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HIV-1 Infection Prevalence and Incidence Trends in Areas of Contrasting Levels of Infection in the Kagera Region, Tanzania, 1987-2000
Abstract
This study aimed at assessing the extent to which decline in HIV infection prevalence reflects decline in incidence in 3 areas with contrasting initial exposure to the HIV epidemic in the Kagera region of Tanzania. A population sample was recruited for the baseline study in 1987 through a multistage cluster sampling technique to determine HIV prevalence. Seronegative individuals identified in the baseline and subsequent studies were followed up for 3 years to yield trends in incidence that were compared for the 3 areas. The overall age-adjusted HIV-1 prevalence in the high-prevalence area of Bukoba urban declined significantly from 24.2% in 1987 to 18.2% in 1993 and later to 13.3% in 1996 (P = 0.0001). In the medium-prevalence area of Muleba, overall age-adjusted prevalence declined significantly from 10.0% in 1987 to 6.8% in 1996 and later to 4.3% in 1999 (P = 0.0003), whereas in the low-prevalence area of Karagwe the prevalence declined from 4.5% in 1987 to 2.6% in 1999 (P = 0.01). In all 3 areas, the most significant decline was consistently observed among women in the age group 15-24 years. No age group exhibited a significant upward prevalence trend. The HIV-1 incidence for Bukoba urban declined from 47.5 to 9.1 per 1000 person-years of observation in 1989 and 1996, respectively, whereas in Muleba it decreased from 8.2 to 3.9 in 1989 and 2000, respectively. Sex-specific estimates indicated a significant decline among women in the high-prevalence area of Bukoba urban from 51.5 to 9.2 per 1000 person-years at risk (P = 0.001). It is concluded that the HIV-1 epidemic in Kagera is on the decrease as reflected by the decline in HIV-1 incidence and prevalence trends particularly among the 15-24 year olds. The decline in the 3 areas of differing magnitude implies that the HIV/AIDS epidemic may be arrested early without necessarily peaking to saturation levels.
... The Kagera region, which had high levels of HIV prevalence in the late 1980s, ranging from 4.5% in the rural Karagwe district to 24% in the urban Bukoba district, has witnessed a decline in HIV, especially in the previously high-prevalence urban district. In all three zones of the study area, the decline was more pronounced among women (see Table 1) (Killewo, Sandstrom, Bredberg-Rådén, Mhalu, Biberfeld & Wall, 1993;Kwesigabo, 2001;Kwesigabo, Killewo, Urassa, Lugalla, Emmelin & Mutembei, 2005). ...
... Prevalence was used as proxy for HIV incidence among 15-to 24-year-olds because prevalence in this age group reflects new HIV infections since those individuals would have just become sexually active. It is rare to find HIV infections of long duration in this age group since almost all the infections will have been recently acquired and hence constitute incident cases (Kwesigabo et al., 2005). ...
... Several factors may explain the declining trends in HIV infections in Kagera region. These include health education, voluntary counselling and testing for HIV (VCT), and promotion of condom use and an increased use of condoms (Kwesigabo et al., 2005). Increased awareness and knowledge about the causes and prevention of HIV and AIDS has been accompanied by more openness and a decrease in HIV stigma. ...
The article presents a synthesis of data from three village case studies focusing on how structural and cognitive social capital may have influenced the progression of the HIV epidemic in the Kagera region of Tanzania. Grounded theory was used to develop a theoretical model describing the possible links between structural and cognitive social capital and the impact on sexual health behaviours. Focus group discussions and key informant interviews were carried out to represent the range of experiences of existing social capital. Both structural and cognitive social capital were active avenues for community members to come together, empower each other, and develop norms, values, trust and reciprocal relations. This empowerment created an enabling environment in which members could adopt protective behaviours against HIV infection. On the one hand, we observed that involvement in formal and informal organisations resulted in a reduction of numbers of sexual partners, led people to demand abstinence from sexual relations until marriage, caused fewer opportunities for casual sex, and gave individuals the agency to demand the use of condoms. On the other hand, strict membership rules and regulations excluded some members, particularly excessive alcohol drinkers and debtors, from becoming members of the social groups, which increased their vulnerability in terms of exposure to HIV. Social gatherings (especially those organised during the night) were also found to increase youths’ risk of HIV infection through instances of unsafe sex. We conclude that even though social capital may at times have negative effects on individuals’ HIV-prevention efforts, this study provides initial evidence that social capital is largely protective through empowering vulnerable groups such as women and the poor to protect against HIV infection and by promoting protective sexual behaviours.
... In recent years, a number of countries with generalised Human immunodeficiency Virus (HIV) epidemic have reported declining prevalence in some population and places and stabilization in others [1][2][3][4][5][6][7]. Variation in the spread of HIV infection has increased the demand for data on HIV prevalence and sexual behaviour trends to inform and evaluate HIV prevention activities. ...
... Prevalent state of sexually transmitted infections [13] including Herpes Simplex Virus type-2 (prevalence 33.2% in this village, unpublished) render rural population vulnerable for more intensified epidemics. This indicates that while HIV-1 infection might be decreasing in urban areas as reported from various recent studies, it could be taking a different direction in rural areas [1][2][3]5,7,22,24,26]. ...
... Contrary to our findings, studies in Rakai Uganda and Kagera, Tanzania have reported a decreased HIV prevalence and incidence [2,3]. However, these studies have been conducted in areas considered to be the epicentre of the HIV/AIDS epidemic in Africa where several prevention programmes are operating and the epidemic is more mature. ...
Monitoring dynamics in HIV-1 infection and risk behaviours is important in evaluating, adjusting and scaling up prevention programmes. The objective of this study was to estimate trends in the prevalence of HIV-1 infection and risk behaviours over 15 years in a rural village population in Kilimanjaro region of Tanzania using repeated population-based cross-sectional surveys.
Four rounds of HIV-1 sero-epidemiological and behavioural surveys were completed during 1991 to 2005 in the study village. House-to-house registrations of people aged 15-44 years with an address in the village were conducted before each survey. All consenting individuals were then interviewed for pertinent risk behaviours and tested for HIV-1 seropositivity.
Participation proportions ranged from 73.0% to 79.1%. Overall, age and sex-adjusted HIV-1 prevalence increased from 3.2% in 1991 to 5.6 % in 2005 (relative increase 75.0%; ptrend < 0.001). The increase was significant for both men and women (ptrends < 0.001) and more evident among women aged 35-44 years (2.0% to 13.0%, ptrend < 0.001). Among participants aged 15-24 years a decrease in number of sexual partners was observed with a corresponding stable HIV-1 prevalence. Participants aged 25-44 years continued to report multiple sexual partners, and this was corroborated with increased HIV-1 prevalence trend (4.0% to 9.0%, ptrends < 0.001). Among men aged 25-44 years and women aged 15-24 years significant increases in condom use were observed (ptrend < 0.01).
The HIV-1 prevalence seems to have increased among older participants but remained stable among younger participants. Encouraging trends toward safer sex practices were observed among young participants, while only modest behavioural changes were seen among the older participants. Prevention efforts in rural areas need to be intensified and to address people of all ages.
... 1,2,9 Tanzania, a country with 7% of its adult population living with HIV, has also noted a diverse pattern in HIV transmission. 10 In some areas, reports show a decreasing trend in the spread of HIV, especially among individuals aged 15-24 years, 8,10,11 while in others, there is gradual increase and continuing spread of HIV. 9,11 Information on time trends, changes in the prevalence and incidence of HIV infection, and the causes is thus important, because it helps to form a basis for planning future prevention and intervention needs. ...
... This pattern of decline in HIV trends among young women has been documented in Kagera and Mbeya regions of Tanzania, in rural and urban Uganda, in Zambia and recently in Zimbabwe, among women attending antenatal care (ANC) and in population-based studies. [3][4][5][6][7][8]11 Taken with caution, the declining HIV infection in young women (o 25 years) may reflect a decline in new infections in the general population, because the infections are relatively new, and the effects of sub-fertility and mortality have not set in. 3,4,8 Evidence has shown that both ulcerative and nonulcerative STIs facilitate transmission and acquisition of HIV. 20 Prompt and effective STI treatment has been shown to reduce vulnerability to HIV at the individual level and in high-risk groups. ...
... This pattern of decline in HIV trends among young women has been documented in Kagera and Mbeya regions of Tanzania, in rural and urban Uganda, in Zambia and recently in Zimbabwe, among women attending antenatal care (ANC) and in population-based studies. [3][4][5][6][7][8]11 Taken with caution, the declining HIV infection in young women (o 25 years) may reflect a decline in new infections in the general population, because the infections are relatively new, and the effects of sub-fertility and mortality have not set in. 3,4,8 Evidence has shown that both ulcerative and nonulcerative STIs facilitate transmission and acquisition of HIV. 20 Prompt and effective STI treatment has been shown to reduce vulnerability to HIV at the individual level and in high-risk groups. ...
The objective of this study was to describe trends over time in HIV prevalence, sexually transmitted infections (STIs) and sexual behaviour among women in Moshi urban, Tanzania. Two cross-sectional studies were conducted in 1999 and in 2002-04 among women attending three primary health-care clinics. They were interviewed and screened for HIV and STIs. There was a significant decrease in HIV prevalence (11.5-6.9%). The decline was greatest among women aged 15-24 years. Syphilis, trichomoniasis, bacterial vaginosis, genital ulcers and reported STI symptoms also decreased significantly over the three-year inter-survey period. The proportion of women reporting casual sex decreased and knowledge of STI symptoms and health-care seeking behaviour improved. Herpes simplex virus type 2, genital warts, age at sexual debut, age at first pregnancy and condom use remained unchanged. In conclusion, decline in curable STIs and casual sex partners may partly explain the observed decline in HIV seroprevalence. Both STIs and sexual behaviour should be monitored in HIV sentinel surveillance. There remains a gap between knowledge of preventive behaviour and actual preventive practices.
... All these pieces of evidence suggest that schooling is the major means by which individuals acquire knowledge, skills, and capacities necessary for future performance in occupation as well as useful for the prevention of disease (Duncan et al., 2002, Kawachi et al., 2010. Though the above has been established in the literature, few studies reported conflicting results regarding the relationship between SES and HIV prevalence in sub-Saharan Africa including Tanzania (Bloom et al., 2002, Kwesigabo et al., 2005, Msamanga et al. 2006, Todd et al., 2006. Studies in Tanzania demonstrated that HIV prevalence was higher among, urban residents than among rural residents (Mnyika et al., 1994); men and women in professional jobs than among agricultural workers (Msisha et al., 2008); individuals with lower educational levels, and those not married monogamously (Kwesigabo et al., 2005). ...
... Though the above has been established in the literature, few studies reported conflicting results regarding the relationship between SES and HIV prevalence in sub-Saharan Africa including Tanzania (Bloom et al., 2002, Kwesigabo et al., 2005, Msamanga et al. 2006, Todd et al., 2006. Studies in Tanzania demonstrated that HIV prevalence was higher among, urban residents than among rural residents (Mnyika et al., 1994); men and women in professional jobs than among agricultural workers (Msisha et al., 2008); individuals with lower educational levels, and those not married monogamously (Kwesigabo et al., 2005). Likewise, women with more than five members per household, and those who spent less on food had a significantly lower HIV prevalence (Msamanga et al., 2006), which will ultimately influence MTCT. ...
Background: There are pieces of evidence of the association between socioeconomic factors and HIV prevalence in sub-Saharan Africa. However, there is a dearth of information on such a relationship in Tanzania. Objective: To determine the relationship between household socioeconomic factors and HIV prevalence among under five-year children in Muheza district, Tanzania. Methods: A facility-based study among HIV-exposed children with their respective mothers/guardians was conducted from June 2015 to June 2016. Information on the HIV status of the child and household socio-demographic characteristics were analyzed in the STATA version 13.0. Results: A total of 576 child-mother/guardian pairs were interviewed. Sixty-one (10.6%) children were confirmed to be HIV positive. The odds of HIV infection were found to be lower among children belonging to the heads of households with secondary and high levels of education (AOR = 0.5, 95% CI 0.2-0.9); P=0.04, those living in wealthier households (AOR = 0.5, 95% CI 0.3-0.9; P=0.03) and those whose mothers/guardians had good knowledge of HIV (AOR = 0.2, 95% CI 0.1-0.3; P<0.001) compared to their counterparts. Conclusion: Children with heads of households having high educational levels and those from wealthier households were associated with reduced odds of acquiring HIV infection in Muheza district.
... Lack of capacity and insufficient diagnostic resources and medicines have resulted to most of the deaths which occurred in hospitals [6]. Human resources capacity, skills and availability have been implicated to high morbidity mortality rates in Tanzania [37], a country that is experiencing human resource crisis and inadequate health system capacity [38][39]. ...
... The decline in deaths due to malaria is likely to be attributed to the decline in incidence and prevalence of the disease during the past decade associated with intensive interventions [37]. A similar decline followed by stabilization in the prevalence of HIV in Tanzania observed in this study has been previously reported by other workers [38]. The availability of antiretroviral drugs is described as a key factor contributing to the decline of deaths among HIV-infected patients and prolonging the lives of those infected [39], hence the observed stabilized mortality pattern. ...
Background
Understanding the causes of inpatient mortality in hospitals is important for monitoring the population health and evidence-based planning for curative and public health care. Dearth of information on causes and trends of hospital mortality in most countries of Sub-Saharan Africa has resulted to wide use of model-based estimation methods which are characterized by estimation errors. This retrospective analysis used primary data to determine the cause-specific mortality patterns among inpatient hospital deaths in Tanzania from 2006–2015.
Materials and methods
The analysis was carried out from July to December 2016 and involved 39 hospitals in Tanzania. A review of hospital in-patient death registers and report forms was done to cover a period of 10 years. Information collected included demographic characteristics of the deceased and immediate underlying cause of death. Causes of death were coded using international classification of diseases (ICD)-10. Data were analysed to provide information on cause-specific, trends and distribution of death by demographic and geographical characteristics.
Principal findings
A total of 247,976 deaths were captured over a 10-year period. The median age at death was 30 years, interquartile range (IQR) 1, 50. The five leading causes of death were malaria (12.75%), respiratory diseases (10.08%), HIV/AIDS (8.04%), anaemia (7.78%) and cardio-circulatory diseases (6.31%). From 2006 to 2015, there was a noted decline in the number of deaths due to malaria (by 47%), HIV/AIDS (28%) and tuberculosis (26%). However, there was an increase in number of deaths due to neonatal disorders by 128%. Malaria and anaemia killed more infants and children under 5 years while HIV/AIDS and Tuberculosis accounted for most of the deaths among adults.
Conclusion
The leading causes of inpatient hospital death were malaria, respiratory diseases, HIV/AIDS, anaemia and cardio-circulatory diseases. Death among children under 5 years has shown an increasing trend. The observed trends in mortality indicates that the country is lagging behind towards attaining the global and national goals for sustainable development. The increasing pattern of respiratory diseases, cancers and septicaemia requires immediate attention of the health system.
... Thus, the adult prevalence decreased from a high of 24% in 1987 in Bukoba town to 18 % in 1993 and later to 13% in 1996. In the medium prevalence rural area of the Muleba district the corresponding figures were 10 % in 1987, 7 % in 1996 and 4 % in 1999 with the fastest decline among women aged 15 to 24 years (Kwesigabo et al., 1998;Kwesigabo et al., 2005). The prevalence has in all probability continued to decline since then. ...
... The rapid decline in prevalence is due to decreased incidence, which is confirmed by the decline of prevalence among recently infected young women. Special studies in Kagera have also shown that the incidence declined by 80% in urban Bukoba and was halved in the Muleba district (Kwesigabo et al., 2005). ...
... west of Lake Victoria, and bordering Rwanda, Burundi and Uganda. Kagera is mostly rural and primarily engaged in producing bananas and coffee in the north, and rain-fed annual crops (maize, sorghum, and cotton) in the south. The region is an area of early and high HIV prevalence, which has led to a significant increase in prime-age mortality rates. Kwesigabo et al. (2005) report on three population samples in 1987 in districts of contrasting exposure in Kagera, and find an overall age-adjusted HIV prevalence of 24.2% in urban Bukoba district; 10.0% in Muleba district, a medium-prevalence area; and 4.5% in Karagwe district, a low-prevalence area. ...
... which has been attributed both to mortality of those infected and lower incidence (as measured by repeat testing of the original population-based sample). In urban Bukoba, prevalence went down to 18.2% in 1993 and 13.3% in 1996. In the other areas studied, prevalence also declined considerably, to 4.3% and 2.6% in Muleba and Karagwe, respectively. Kwesigabo et al. (2005) note that the decline in these areas of different initial HIVexposure suggests that the epidemic may have been arrested early without necessarily peaking to " saturation levels " (in which all people most at risk are infected). Nevertheless, and of relevance to our study, a rapid decline in prevalence, even without a change in the incid ...
HIV/AIDS is drastically changing the demographic landscape in high-prevalence countries in Africa. The prime-age adult population bears the majority of the mortality burden, and these “missing” prime-age adults have implications for the socioeconomic well-being of surviving family members. This study uses a 13-year panel from Tanzania to examine the impacts of prime-age mortality on the time use and health outcomes of older adults, with a focus on long-run impacts and gender dimensions. Prime-age deaths are weakly associated with increases in working hours of older women when the deceased adult was coresident in the household. The association is strongest when the deceased adult was living with the elderly individual at the time of death and for deaths in the distant past, suggesting that shorter-run studies may not capture the full extent of the consequences of adult mortality for survivors. Holding more assets seems to buffer older adults from having to work more after these shocks. Most health indicators are not worse for older adults when a prime-age household member has died, although more distant adult deaths are associated with an increased probability of acute illness for the surviving elderly. For deaths of children who were not residing with their parents at baseline, the findings show no impact on hours worked or health outcomes.
... There is a diverse pattern of trends in HIV prevalence for different geographical areas in the country. In some areas the reports show a decreased trend in the prevalence and incidence of HIV, especially among individuals aged 15–24 years [3,4]. In others, there is a gradual and continuing spread of HIV [4,5]. ...
... In others, there is a gradual and continuing spread of HIV [4,5]. In all areas however, women continue to experience higher rates of prevalence and incidence than men2345, and 58% of the HIV-infected in the whole country are women [6] . There is therefore a need to elucidate risk factors continuing to contribute to the HIV epidemic among women of reproductive age. ...
Women continue to be disproportionately affected by HIV in Tanzania, and factors contributing to this situation need to be identified. The objective of this study was to determine social, behavioral and biological risk factors of HIV infection among pregnant women in Moshi urban, Tanzania. In 2002-2004, consenting women (N = 2654), attending primary health clinics for routine antenatal care were interviewed, examined and biological samples collected for diagnosis of HIV and other sexually transmitted/reproductive tract infections.
The prevalence of HIV was 6.9%. The risk for HIV was greater among women whose male partner; had other sexual partners (adjusted odds ratio [AOR], 15.11; 95% confidence interval [CI], 8.39-27.20), traveled frequently (AOR, 1.79; 95% CI, 1.22-2.65) or consumed alcohol daily (AOR, 1.68; 95% CI, 1.06-2.67). Other independent predictors of HIV were age, number of sex partners, recent migration, and presence of bacterial vaginosis, genital ulcer, active syphilis and herpes simplex virus type 2.
Development of programs that actively involve men in HIV prevention is important in reducing transmission of HIV in this population. Further, interventions that focus on STI control, the mobile population, sexual risk behavior and responsible alcohol use are required.
... Therefore, the current finding showing much a higher prevalence in this rural adult population (6.4% unadjusted)) suggests that the rate of HIV-1 infection may be increasing in this community. This is in line with other published studies in Tanzania [6,15,17,24]. It has been reported that despite the observed decrease in HIV-1 prevalence in some populations in Africa, variability in prevalence exists between and within countries [1,3]. ...
... This means that we can not establish causal-effect relationships between HIV-1 and those factors. However, these factors have also been described in stronger designs to be associated with HIV infection [5,17,23,24] securing their importance in this population. ...
Variability in stages of the HIV-1 epidemic and hence HIV-1 prevalence exists in different areas in sub-Saharan Africa. The purpose of this study was to investigate the magnitude of HIV-1 infection and identify HIV-1 risk factors that may help to develop preventive strategies in rural Kilimanjaro, Tanzania.
A cross-sectional study was conducted between March and May of 2005 involving all individuals aged between 15-44 years having an address in Oria Village. All eligible individuals were registered and invited to participate. Participants were interviewed regarding their demographic characteristics, sexual behaviors, and medical history. Following a pre-test counseling, participants were offered an HIV test.
Of the 2 093 eligible individuals, 1 528 (73.0%) participated. The overall age and sex adjusted HIV-1 prevalence was 5.6%. Women had 2.5 times higher prevalence (8.0% vs. 3.2%) as compared to men. The age group 25-44 years, marriage, separation and low education were associated with higher risk of HIV-1 infection for both sexes. HIV-1 infection was significantly associated with >2 sexual partners in the past 12 months (women: Adjusted odds ratio [AOR], 2.5 (95%CI: 1.3-4.7), and past 5 years, [(men: AOR, 2.2 (95%CI:1.2-5.6); women: AOR, 2.5 (95%CI: 1.4-4.0)], unprotected casual sex (men: AOR,1.8 95%CI: 1.2-5.8), bottled alcohol (Men: AOR, 5.9 (95%CI:1.7-20.1) and local brew (men: AOR, 3.7 (95%CI: 1.5-9.2). Other factors included treatment for genital ulcers and genital discharge in the past 1 month. Health-related complaints were more common among HIV-1 seropositive as compared to seronegative participants and predicted the presence of HIV-1 infection.
HIV-1 infection was highly prevalent in this population. As compared to our previous findings, a shift of the epidemic from a younger to an older age group and from educated to uneducated individuals was observed. Women and married or separated individuals remained at higher risk of infection. To prevent further escalation of the HIV epidemic, efforts to scale up HIV prevention programmes addressing females, people with low education, lower age at marriage, alcohol consumption, condom use and multiple sexual partners for all age groups remains a top priority. Care and treatment are urgently needed for those infected in rural areas.
... That is, the risk has decreased from one person in twenty being infected each year to one person in a hundred. The figures are slightly better for women between the ages of 15-24 years, for whom a decreased incidence was also noted in areas with middle and low initial prevalence (29). ...
... However, the good news is that the situation may be better than feared. The Bukoba-study shows that the most significant decline in HIV-incidence is among women in the age group 15-24 years (29). If these figures are correct, and assuming the virus is as contagious and people as susceptible as before, this must reflect a change in sexual behaviour. ...
The overall picture of health in sub-Saharan Africa can easily be painted in dark colours. The aim of this viewpoint is to discuss epidemiological data from Tanzania on overall health indicators and the burden of malaria and HIV. Is the situation in Tanzania improving or deteriorating? Are the health-related millennium development goals (MDG) on reducing under-five mortality, reducing maternal mortality and halting HIV and malaria within reach?
Conclusion: Child mortality and infant mortality rates are decreasing quite dramatically. Malaria prevention strategies and new effective treatment are being launched. The MDG 4 on child mortality is clearly within reach, and the same optimism may apply to MDG 6 on combating malaria.
... The first AIDS cases were reported there in 1983, and the first HIV seroprevalence study conducted in 1987 estimated the prevalence to be 24.2%in Bukoba urban district, one of the high-prevalence areas in the region [36]. The explosion of the HIV epidemic in that region was mainly attributed to the mobility of the Tanzania People's Defence Force as they helped wage a liberation struggle in neighboring Uganda [12]. ...
... The prevalence as well as the incidence of HIV in Kagera has shown a steady decline from the mid-1980s to the present time, with the most recent prevalence estimated at 3.9%. This trend is partly the result of changes in people's sexual behaviors over time as a result of the concentrated intervention efforts in the region [36]. The fact that Kagera no longer has the highest HIV prevalence in the country and that the epidemic has now moved across the country to the southern regions of Mbeya and Iringa points to the complex and dynamic nature of the epidemic, and indicates that there is something about context that fosters the growth and movement of the epidemic within different areas in Tanzania. ...
To examine the extent to which the regional and neighborhood distribution of HIV in Tanzania is caused by the differential distribution of individual correlates and risk factors.
Nationally representative, cross-sectional data on 12,522 women and men aged 15-49 years from the 2003-2004 Tanzanian AIDS Indicator Survey. Three-level multilevel binary logistic regression models were specified to estimate the relative contribution of regions and neighborhoods to the variation in HIV seroprevalence.
Spatial distribution of individual correlates (and risk factors) of HIV do not explain the neighborhood and regional variation in HIV seroprevalence. Neighborhoods and regions accounted for approximately 14 and 6% of the total variation in HIV. HIV prevalence ranged from 1.8% (Kigoma) to 6.7% (Iringa) even after adjusting for the compositional make-up of these regions. An inverse association was observed between log odds of being HIV positive and neighborhood poverty [odds ratio (OR) 0.24, 95% confidence interval (CI) 0.09-0.61] and regional poverty (OR 0.97, 95% CI 0.95-0.99).
Our study provides evidence for independent contextual variations in HIV, above and beyond that which can be ascribed to geographical variations in individual-level correlates and risk factors. We emphasize the need to adopt both a group-based and a place-based approach, as opposed to the dominant high-risk group approach, for understanding the epidemiology of HIV as well as for developing HIV intervention activities.
... Over the past four decades, behavioural changes among Tanzanians, influenced by both increased awareness campaigns and access to ARVs, have played a crucial role in reducing HIV/AIDS transmission. Kwesigabo (2005) argues that alongside biomedical advancements, individual behavioural adjustments have contributed significantly to the declining epidemic trend. This finding aligns with global efforts recommended by UNAIDS (2005), which emphasize comprehensive care, stigma reduction, and community engagement as pivotal strategies in combating HIV/AIDS. ...
The prevalence of HIV/AIDS among Tanzanians, especially in the Kagera region, has been widely recognized since 1983 when the first cases of HIV infection were diagnosed. This study employed a qualitative approach and a narrative research design to uncover the socially constructed reality surrounding the HIV/AIDS epidemic in Tanzania. By delving into detailed narratives provided by key respondents, the study examined the evolving anthropological perspectives on HIV/AIDS before and after the scientific diagnosis of the epidemic in Tanzania, spanning the period from 1983 to 2023. The study found that, initially, there was a sense of mystery surrounding the origin and nature of the illness, as it seemed to emerge unexpectedly. By then, witchcraft was believed to be the cause of this calamity. However, a significant moment occurred in 1983 when three patients received medical diagnoses at Ndolage Hospital in Muleba District. The diagnosis and awareness campaign represented a pivotal moment in people's perceptions, gradually transitioning from associating HIV/AIDS with witchcraft to understanding the scientific explanation of the epidemic. Nonetheless, stigma towards AIDS patients persisted until the introduction of antiretroviral (ARV) medication in 2004. With the availability of ARVs, trust was restored among HIV/AIDS patients, enabling them to engage in daily activities without encountering stigma or discrimination in their communities. Additionally, ARVs contributed to diminishing the stigma associated with HIV/AIDS. As more individuals gained access to treatment and led healthier lives with HIV, misconceptions and fears surrounding the disease diminished, fostering greater acceptance and support for those living with HIV. The study's findings highlight the significance of culturally tailored interventions that address the disparity between deeply rooted cultural beliefs regarding the origins of illness and scientific explanations. These interventions encompass organizing workshops and community forums that offer culturally sensitive information about the scientific understanding of diseases such as HIV/AIDS, while also acknowledging and respecting traditional beliefs. Therefore, it is crucial that when the association between the epidemic and cultural beliefs, as well as stigma, is evident, awareness campaigns are maintained through community-driven initiatives and continuous educational efforts.
... Over the past four decades, behavioural changes among Tanzanians, influenced by both increased awareness campaigns and access to ARVs, have played a crucial role in reducing HIV/AIDS transmission. Kwesigabo (2005) argues that alongside biomedical advancements, individual behavioural adjustments have contributed significantly to the declining epidemic trend. This finding aligns with global efforts recommended by UNAIDS (2005), which emphasize comprehensive care, stigma reduction, and community engagement as pivotal strategies in combating HIV/AIDS. ...
... Recent scholarship on HIV prevention and education has argued that in the absence of a cure, the most promising strategy for curtailing the prevalence of the disease is to modify the socially and culturally rooted sexual behaviors [1,2]. In fact, sexual behavioral modification has been the most consistent explanation for the decline in HIV/ AIDS prevalence in sub-Saharan Africa [3]. For instance, [2] found that changes in sexual behaviors as well as church policy demanding testing couples before marriage has had a significant influence on lowering HIV/AIDS prevalence in Kagera Region in Tanzania. ...
... south. Projections based on the 2002 census put the population of Kagera at a little over 2.5 million people (URT, 2006b). Under half of the population was between 0–14 years and around 5% were over 65 years old. Kagera is known for being one of the early epicenters of HIV/AIDS with the first cases having been detected at Ndolage Hospital in 1983. Kwesigabo et al. (2005) studied trends in prevalence rates and note their steady decline over the years. While urban Bukoba recorded a peak of 24% prevalence in 1987, other districts had figures well below that. The Tanzanian Commission for AIDS (TACAIDS), the National Bureau of Statistics (NBS), and ORC Macro (2005) put the region-wide prevalence in 2004 at 3 ...
A rather unique panel tracking more than 3,300 individuals from households in rural Kagera, Tanzania during 1991/4-2010 shows that about one in two individuals/households who exited poverty did so by transitioning from agriculture into the rural nonfarm economy or secondary towns. Only one in seven exited poverty by migrating to a large city, although those moving to a city experienced on average faster consumption growth. Further analysis of a much larger cross-country panel of 51 developing countries cannot reject that rural diversification and secondary town development lead to more inclusive growth patterns than metropolitization. Indications are that this follows because more of the poor find their way to the rural nonfarm economy and secondary towns, than to distant cities. The development discourse would benefit from shifting beyond the rural-urban dichotomy and focusing instead more on how best to urbanize and develop the rural nonfarm economy and secondary towns.
... However, those studies were conducted in areas Mmbaga, Hussain, Leyna, Klouman, Masenga, Sam, Mnyika and that could be considered HIV epicentres. Incidence of HIV-1 infection in this population was comparable to that reported for the rural area of Muleba in the Kagera region of Tanzania at the time of this study (see Killewo et al., 1993; Kwesigabo, Killewo, Urassa, Lugalla, Emmelin, Mutembei, Biberfeld, Wall & Sandstrom, 2005). As incidence data represent the most effective direct measure of whether HIV transmission is increasing or abating in a given population (Wawer, Serwadda, Gray, Sewankambo, Li, Nalugoda, Lutalo & Konde-Lule, 1997), our findings suggest that HIV-1 infection was on the increase in this rural population. ...
This study aimed at describing the prevalence and incidence of HIV-1 and change in the prevalence of reproductive tract infections (RTIs) and sexual risk behaviours in the rural Kilimanjaro region of Tanzania. Two cross-sectional surveys among the total village population of Oria were conducted in 1991 and 1993. All individuals with a permanent address in the village were registered and invited to participate. After informed consent, participants gave blood for HIV-1 testing. Participants aged 15–44 years were interviewed regarding their socio-demographic characteristics and sexual risk behaviours and underwent genital examination and testing for RTIs. In 1991 and 1993, respectively, 3 239 (83.6%) and 2 191 (76.9%) individuals in the village participated. Prevalence of HIV-1 increased from 1.3% to 1.8%, but the difference was not significant (p = 0.17). HIV-1 incidence was 13.0/1000 person-years-at-risk (PYAR) for women and 4.3/1000 PYAR for men (relative risk was 3.0; 95% CI: 1.12–8.16). There was a significant increase in the prevalence of gonorrhoea, bacterial vaginosis and vaginal candidiasis (p < 0.001). The percentage of individuals who reported having multiple sexual partners during the 12 months preceding the survey increased from 12.9% to 24.1% (p < 0.001). The results suggest that RTIs and HIV-1 infections increased in this population in the early 1990s. Women were at higher risk of HIV-1 infection as compared to men. Sexual risk behaviours and RTIs may have contributed to HIV-1 transmission in this community. The data collected may help to inform the future design and evaluation of various intervention measures.
... Similar HIV-1 incidence and related epidemiological data have been reported from Uganda, Tanzania, Malawi, Zimbabwe, and elsewhere. [3][4][5][6][7][8][9][10][11][12][13] Although related, HIV observational cohort data in Kenya have been published, most, if not all, of the data have been from urban and higher risk populations [14][15][16] or, in the case of incidence rates methods, may utilize estimates based upon the BED HIV-1 Capture EIA (BED) assay with or without supplemental adjustments. [17][18][19] The Kericho HIV cohort study utilized rigorous, gold standard laboratory assays (ie, enzymelinked immunosorbent assay and Western blot) and provides primary HIV-1 incidence data from a traditionally nonhigh risk population in a rural setting. ...
Background: Incidence data from prospective cohort studies using rigorous laboratory methods are important in designing and evaluating HIV vaccine and therapeutic clinical trials and health care programs. We report 36-month HIV-1 incidence rates and demographic and psychosocial risks from the Kericho cohort in rural Kenya's southern Rift Valley Province.
Methods: Thirty-six month, prospective, closed, observational cohort study of adult plantation workers and dependents followed biannually. HIV-1 incidence rates per 100 person-years (py) were calculated, and Cox regression analyses were used to estimate hazards ratios (HR) associated with seroconversion.
Results: Two thousand four hundred volunteers (mean age ± SD = 30.1 ± 8.5 years; 36.5% women) participated. Twenty-nine new HIV cases were identified in year 1 of follow-up, which increased to cumulative totals of 49 and 63 cases in years 2 and 3, respectively. The corresponding 1-, 2-, and 3-year incidence rates were 1.41 [95% confidence interval (CI) = 0.95-2.02], 1.16 (95% CI = 0.86-1.54), and 1.00 (95% CI = 0.77-1.28) per 100 py. Risk factors associated with HIV seroconversion included the following: of the Luo tribe (HR = 3.31; 95% CI = 1.65-6.63), marriage more than once (HR = 2.83; 95% CI = 1.20-6.69), self-reported male circumcision (HR = 0.32; 95% CI = 0.17-0.60), history of sexually transmitted infection (HR = 2.40; 95% CI = 1.09-5.26), history of substance abuse during sex (HR = 2.44; 95% CI = 1.16-5.13), and history of transactional sex (HR = 3.30; 95% CI = 1.79-6.09).
Conclusions: HIV-1 incidence rates were relatively low in adult plantation workers and dependents in rural Kenya. Cohorts including higher risk populations (eg, commercial sex workers) warrant consideration for regional HIV preventive vaccine trials. Even low incidence, well-described cohorts generate valuable epidemiological clinical trial data.
... Key informant interviews and focus group discussions (FGDs) were performed in three case villages selected to represent high, medium and low prevalence zones, based on estimates from the 1987 survey (Kwesigabo et al., 2005). The study was performed in one ward in each of the identified zones. ...
We present data from an exploratory case study characterising the social capital in three case villages situated in areas of varying HIV prevalence in the Kagera region of Tanzania. Focus group discussions and key informant interviews revealed a range of experiences by community members, leaders of organisations and social groups. We found that the formation of social groups during the early 1990s was partly a result of poverty and the many deaths caused by AIDS. They built on a tradition to support those in need and provided social and economic support to members by providing loans. Their strict rules of conduct helped to create new norms, values and trust, important for HIV prevention. Members of different networks ultimately became role models for healthy protective behaviour. Formal organisations also worked together with social groups to facilitate networking and to provide avenues for exchange of information. We conclude that social capital contributed in changing HIV related risk behaviour that supported a decline of HIV infection in the high prevalence zone and maintained a low prevalence in the other zones.
... Kagera is known for being one of the early epicentres of HIV/AIDS with the first cases having been detected at Ndolage Hospital in 1983. Kwesigabo et al. (2005) studied trends in prevalence rates and note their steady decline over the years. While urban Bukoba recorded a peak of 24 per cent prevalence in 1987, other districts had figures well below that. ...
This paper uses linked qualitative and quantitative data to explore the growth trajectories of matched households in the Kagera region of Tanzania, finding that agriculture and trade provided the two main routes out of poverty. The interplay between initial conditions, shocks, networks and experiences of life beyond their village determine whether a person moves out of poverty in the following decade.
... We do not, however, fi nd any evidence of this in the data in terms of clustering of deaths or deaths caused by localized epidemics. 8. Killewo et al. (1990), Killewo et al. (1993, and Kwesigabo et al. (2005) have provided epidemiological data on HIV/AIDS prevalence and incidence in the region. at baseline, 5.8% did not participate, mainly due to the household having relocated after enumeration (53%). ...
This article presents unique evidence that orphanhood matters in the long run for health and education outcomes in a region of northwestern Tanzania. We study a sample of 718 non-orphaned children surveyed in 1991-1994 who were traced and reinterviewed as adults in 2004. A large proportion, 19%, lost one or more parents before age 15 in this period, allowing us to assess permanent health and education impacts of orphanhood. In the analysis, we control for a wide range of child and adult characteristics before orphanhood, as well as community fixed effects. We find that maternal orphanhood has a permanent adverse impact of 2 cm of final height attainment and one year of educational attainment. Expressing welfare in terms of consumption expenditure, the result is a gap of 8.5% compared with similar children whose mothers survived until at least their 15th birthday.
... Studies, however, have shown how the HIV prevalence has drastically fallen in the years between 1984 and 1999. In the high prevalence area of Bukoba Urban, it has fallen from 24.2% to 13.3%; in the medium prevalence of Muleba, from 10% to 4.3%, and; in the low prevalence area of Karagwe, from 4.5% to 2.6% (Kwesigabo et al. 2005). The reasons for the decrease of the prevalence are linked to changes in sexual behaviours, norms, values and customs that are of high risk for HIV transmission. ...
Kagera is one of the areas considered to be an epicentre of the HIV/AIDS epidemic in Tanzania. This has been due to linking HIV/AIDS and the cross-border trade between Uganda and Tanzania, an activity that was due to lack of essential commodities after the Uganda-Tanzania War of 1978-1981. In a survey in the landing sites of Lake Victoria, where one of the elements is to know the state of HIV/AIDS, it is found out that people are giving up in their struggle against HIV/AIDS, a situation that leads to the perception of contracting HIV/AIDS being an "occupational hazard". As the African sexual permissiveness theory has been at the back of the bio-medical discourse and the eventual behavioural change paradigms in guiding HIV/AIDS interventions, this article proposes change of discourse by having the meaningful life discourse in HIV/AIDS interventions.
... For comparison, in a cohort of police officers in Dar es Salaam, Tanzania [31], the HIV-1 prevalence and incidence was on the same level or higher compared with other urban [32] and rural [33,34] populations in Tanzania. ...
To study prevalence and incidence of HIV-1 and HIV-2 between 1990 and 2007 and to examine impact of the civil war in 1998-1999. We also wanted to investigate possible interaction between HIV-1 and HIV-2.
Open prospective cohort study of 4592 police officers in Guinea-Bissau, West Africa.
Analysis of HIV-1 and HIV-2 prevalence and incidence divided in 2-3 years time strata.
HIV-1 prevalence (including HIV-1/HIV-2 dual reactivity) increased gradually from 0.6 to 3.6% before the war and was 9.5% in the first serosurvey after the war. HIV-1 incidence more than doubled during and shortly after the war, from 0.50 to 1.22 per 100 person-years. Both prevalence and incidence of HIV-1 decreased in the following periods after the war. HIV-2 prevalence decreased from 13.4 to 6.2% during the entire study period and HIV-2 incidence decreased from 1.38 to 0.18 per 100 person-years. Adjusted incidence rate ratios of HIV-1 incidence in HIV-2-positive participants compared with HIV-negative participants ranged from 1.02 to 1.18 (not significant) depending on the confounding variables included.
HIV-1 has increased, whereas HIV-2 has decreased and the risk of acquiring HIV-1 is now more than four times higher as compared with HIV-2. The civil war in 1998-1999 appears to have induced a temporary increase in HIV-1 transmission, but now a stabilization of HIV-1 incidence and prevalence seems to have taken place. There was no evidence of a protective effect of HIV-2 against HIV-1 infection.
... The few studies that have examined the relationship between socioeconomic status (SES) and HIV/AIDS have produced mixed and conflicting results. [3][4][5][6][7] It has been posited that in early epidemic stages HIV/AIDS primarily affects the wealthy and that as the epidemic progresses the disease disproportionately affects the poor. 8 Although, poverty is believed to be a significant driver of HIV, the relationship is not very clearcut. ...
To examine the relationship between multiple dimensions of socioeconomic status (SES) and HIV seroprevalence in Tanzania.
Using a large nationally representative sample of 7515 sexually active adults drawn from the 2003-04 Tanzania HIV/AIDS Indicator Survey, we analysed the relationship between multiple SES measures and HIV seroprevalence using weighted logistic regression models.
In adjusted models, individuals in the highest quintile of standard of living had increased odds ratio (OR) of being HIV-positive (male: OR 2.38, 95% CI 1.17-4.82; female: OR 3.74, 95% CI 2.16-6.49). Occupational status was differentially associated with HIV in men and women; women in professional jobs had higher OR of being HIV-positive (OR 1.54, 95% CI 1.02-2.38), whereas unemployed men had higher risk of being HIV-positive (OR 3.49, 95% CI 1.43-8.58). No marked association was found between increasing education and HIV seroprevalence for men (P = 0.83) and women (P = 0.87).
Contrary to the prevailing perception that low SES individuals tend to be more vulnerable to HIV-infection, we found a positive association between standard of living and HIV-infection. Strategies aimed at reducing HIV-infection needs to be cognizant of the complex social heterogeneity in the patterns of HIV-infection.
... Research on ANC sentinel surveillance has mainly been focused on the role of behavioural data in ANC surveil- lance [13], uses of prevalence data [14], coverage [15], assessing the trends of HIV prevalence161718 , comparison between HIV prevalence from ANC and community prevalence [9,10] and methods of adjustment of estimates from ANC surveillance [11,19]. In addition some research has addressed the differences in fertility according to HIV status [2,20]. ...
Most estimates of HIV prevalence have been based on sentinel surveillance of pregnant women which may either under-estimate or over-estimate the actual prevalence in adult female population. One situation which can lead to either an underestimate or an overestimate of the actual HIV prevalence is where there is a significant difference in fertility rates between HIV-positive and HIV-negative women. Our aim was to compare the fertility rates of HIV-infected and HIV-uninfected women in Cameroon in order to make recommendations on the appropriate adjustments when using antenatal sentinel data to estimate HIV prevalence.
Cross-sectional, population-based study using data from 4493 sexually active women aged 15 to 49 years who participated in the 2004 Cameroon Demographic and Health Survey.
In the rural area, the age-specific fertility rates in both HIV positive and HIV negative women increased from 15-19 years age bracket to a maximum at 20-24 years and then decreased monotonically till 35-49 years. Similar trends were observed in the urban area. The overall fertility rate for HIV positive women was 118.7 births per 1000 woman-years (95% Confidence Interval [CI] 98.4 to 142.0) compared to 171.3 births per 1000 woman-years (95% CI 164.5 to 178.2) for HIV negative women. The ratio of the fertility rate in HIV positive women to the fertility rate of HIV negative women (called the relative inclusion ratio) was 0.69 (95% CI 0.62 to 0.75).
Fertility rates are lower in HIV-positive than HIV-negative women in Cameroon. The findings of this study support the use of summary RIR for the adjustment of HIV prevalence (among adult female population) obtained from sentinel surveillance in antenatal clinics.
... In respect of HIV epidemics there is also some enlightenment. In the Kagera region of Tanzania the HIV prevalence declined continuously from 1987 to 2000 [7], which may be associated with interventional activities and behavioural changes [8]. The lack of vital statistics hampers policy-makers' and managers' ability to make proper decisions regarding reproductive health. ...
... Despite this widespread use of ANCbased trends, validity and accuracy concerns as well as changing HIV dynamics in general populations as the epidemic matures, continue to pause interpretation challenges when these estimates are extrapolated to the general population[6,8910. However, population-based data on trends in HIV prevalence and related risk factors are still limited because only a few serial surveys have been conducted[2,10111213. Furthermore, potential biases are also likely to hamper validity and reliability of population-based HIV surveys[14]. ...
Abstract Background Understanding the epidemiological HIV context is critical in building effective setting-specific preventive strategies. We examined HIV prevalence patterns in selected communities of men and women aged 15–59 years in Zambia. Methods Population-based HIV surveys in 1995 (n = 3158), 1999 (n = 3731) and 2003 (n = 4751) were conducted in selected communities using probability proportional to size stratified random-cluster sampling. Multivariate logistic regression and trend analyses were stratified by residence, sex and age group. Absence
... A similar pattern of change in ANC-based HIV prevalence reported here has been observed in the majority of surveillance sites in Zambia, and the most likely scenario is that similar change mechanisms were seen in many of these populations (Sandøy et al. 2006). Historically, the only and dramatic parallel declines and not associated with postponement of birth, observed from both antenatal-and population-based data was in Kagera region during the 1990s (Asiimwe-Okiror et al. 1997; Kwesigabo et al. 1998 Kwesigabo et al. , 2005). The declines in Kagera may have been a signal of continuing declines in the general population as the epidemic matured. ...
To determine to what extent antenatal clinic (ANC)-based estimates reflect HIV prevalence trends among men and women in a high prevalence urban population.
Examination of data from serial population-based HIV surveys in 1995 (n = 2115), 1999 (n = 1962) and 2003 (n = 2692), and ANC-based surveillance in 1994 (n = 450), 1998 (n = 810) and 2002 (n = 786) in the same site in Lusaka, Zambia. The population-based surveys recorded refusal rates between 6% and 10% during the three rounds.
Among ANC attendees, prevalence declined by 20% (25.0% to 19.9%; P = 0.101) in the age group 15-24 years and was stable overall. In the general population, the prevalence declined by 49% (P < 0.001) and by 32% (P < 0.001) in age group 15-24 and 15-49, respectively. Among women only, HIV prevalence declined by 44% (22.5% to 12.5%; P < 0.001) and by 27% (29.6% to 21.7%; P < 0.001) in age group 15-24 and 15-49 years, respectively. In addition, prevalence substantially declined in higher educated women aged 15-24 years (20.7% to 8.5%, P < 0.001).
ANC-based estimates substantially underestimated declines in HIV prevalence in the general population. This seemed to be partially explained by a combination of marked differentials in prevalence change by educational attainment and changes in fertility-related behaviours among young women. These results have important implications for the interpretation of ANC-based HIV estimates and underscore the importance of population-based surveys.
Background:
The HIV epidemic exacerbated the prevalence of prime-aged adult death in many parts of sub-Saharan Africa, resulting in increased rates of orphanhood. Little is known about whether this will coincide with adverse psychosocial wellbeing in adulthood for those who were orphaned at childhood.
Methods:
We studied a cohort of 1,108 children from Kagera, a region of Tanzania that was heavily affected by HIV early in the epidemic. During the baseline data collection in 1991-94 these children were aged 0-16 years and had both parents alive. We followed them roughly 16-19 years later in 2010, by which time 531 children (36%) had lost either one or both parents before their 19 birthday. We compared the 2010 10-item Rosenberg Self-Esteem Scale (RSES) score between children who lost a parent before the age of 19 and those who did not. We used the baseline data to control for pre-orphanhood confounders. This is important, since we find that children who will lose their fathers in the future before age 19 came from somewhat lower socioeconomic backgrounds.
Results:
We found no correlation between maternal death and self-esteem measured through RSES. Paternal death was strongly correlated to lower levels of self-esteem (0.2 standard deviations lower RSES CI95% 0.059-0.348) and the correlation was stronger when the death occurred during the child's teenage years. These effects are net of socioeconomic differences that existed before the orphanhood event.
Conclusions:
Our study supports the further development and piloting of programmes that address psychosocial problems of orphans.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial License 4.0 (CCBY-NC), where it is permissible to download, share, remix, transform, and buildup the work provided it is properly cited. The work cannot be used commercially without permission from the journal.
In this commentary we introduce the population age and gender distributions, the birth rate, and life expectancy in Tanzania's largely agricultural society and highlight the vulnerable status of mothers and children. We present underlying causes of poor health, the leading causes of Disability-Adjusted Life Years and review threats from exposure to disease, toxic substances, and injuries that require protection of populations and control efforts. We summarize health challenges posed by malaria, tuberculosis, and HIV/AIDS, non-communicable diseases, and by new threats that may change the picture of disease and require adjustments in how training institutions prepare the health workforce.
Objective:
Previous studies found educated individuals to have higher risk of human immunodeficiency virus (HIV)-1 infection in Africa. A reverse in this association was predicted. We investigated the change in this association from 1991 to 2005 in a rural population in Tanzania.
Study design:
Two cross-sectional surveys were conducted in 1991(N = 1,152, response rate 76.4%) and 2005 (N = 1,528, 73.0%). Consenting individuals aged 15 to 44 years living in Oria village were interviewed and gave blood for HIV-1 testing.
Results:
Primary [adjusted odds ratio (AOR), 2.7; 95% confidence interval (CI): 1.3-20.0] and secondary/higher education (AOR, 4.5; 95% CI: 1.4-24.9) were associated with increased risk of HIV-1 infection in 1991. A reversed association was observed in 2005 where reduced odds of infection were associated with primary (AOR, 0.5; 95% CI: 0.2-0.8) and secondary/higher education (AOR, 0.4; 95% CI: 0.3-0.9). This was most pronounced among educated men. Corresponding reduction in risk behaviors were observed. Increased odds of reporting ever use of condom (AOR, 2.8; 95% CI: 1.1-7.3) and 70% reduction in reporting >or=2 sexual partners in the past year was observed among educated women. Educated men reported 60% reduction in the odds of reporting >or=2 sexual partners in the past month preceding the last survey.
Conclusions:
A reversed association between education attainment and HIV-1 infection was observed in this population between 1991 and 2005. Education seems to have an empowering role in women. Decreased risk among educated men may have an impact on HIV-1 transmission. Improving education sector in rural areas might be instrumental in the fight against the HIV epidemic.
This paper presents unique evidence that orphanhood matters in the long-run for health and education outcomes, in a region of Northwestern Tanzania. We study a sample of 718 non-orphaned children surveyed in 1991-94, who were traced and reinterviewed as adults in 2004. A large proportion, 19 percent, lost one or more parents before the age of 15 in this period, allowing us to assess permanent health and education impacts of orphanhood. In the analysis, we can control for a wide range of child and adult characteristics before orphanhood, as well as community fixed effects. We find that maternal orphanhood has a permanent adverse impact of 2 cm of final height attainment and one year of educational attainment. Expressing welfare in terms of consumption expenditure, the result is a gap of 8.5 percent compared to similar children whose mother survived till at least their 15 th birthday.
In sub-Saharan Africa human immunodeficiency virus (HIV) epidemic has a major influence on tuberculosis (TB) epidemiology. Ethiopia is among the countries in the region most heavily affected by the HIV and TB. Recent evidence indicated that the HIV/AIDS epidemic may be more heterogeneous in different age categories, between males and females, across different risk groups, and/or in different geographical settings than previously believed. This heterogeneity implies that HIV/AIDS programs for a particular area should be based not only on national-level statistics, but it also needs to be geographically focused, and directed to those regions, districts or communities exhibiting higher prevalence. The current study was aimed to evaluate trends of the prevalence of HIV and TB infection in Wolaita Sodo town.
This is institution based retrospective study and it covered the period of 2004 to 2008. We reviewed the medical records of 7375 patients with a diagnosis of TB and 11447 individuals screened for HIV at three heath institutions located in Wolaita Sodo town. Statistical significance of trend in proportions over the study period was evaluated by chi2 test for trend using Epi-Info version 6.03. P-value less than 0.05 was reported as being statistically significant.
The prevalence of TB was 17.1% (1262/7375), that of HIV was 10.7% (1220/11447) and the prevalence of HIV and TB co-infection was 7.8% (36/459). With the exception of 2008 annual TB cases, the prevalence of TB in Wolaita Sodo showed an overall significant decline over the study period (chi2 = 59.4, P < 0.001). The prevalence of TB (P = 0.003) and HIV (P < 0.001) has an increasing trend with age for study participants younger than 44 years and decrease then after (P < 0.001). Being a female was a significant risk factor for HIV infection (OR = 1.35; 95% CI: 1.23 to 1.47) but not for TB infection.
In the study area annual prevalence of TB, HIV and TB/HIV co-infection were significantly decreased from 2004 to 2008 in the age range of 25-44 years. However, the level of infection of these infections is still high and remains as being public health problems in the study area. Therefore, a good practice of TB and HIV control strategy adopted in the area should be strictly continued.
This article presents an extension of the cohort-component model of population projection (CCMPP) first formulated by Heuveline (2003) that is capable of modeling a population affected by HIV. Heuveline proposes a maximum likelihood approach to estimate the age profile of HIV incidence that produced the HIV epidemics in East Africa during the 1990s. We extend this work by developing the Leslie matrix representation of the CCMPP, which greatly facilitates the implementation of the model for parameter estimation and projection. The Leslie matrix also contains information about the stable tendencies of the corresponding population, such as the stable age distribution and time to stability. Another contribution of this work is that we update the sources of data used to estimate the parameters, and use these data to estimate a modified version of the CCMPP that includes (estimated) parameters governing the survival experience of the infected population. A further application of the model to a small population with high HIV prevalence in rural South Africa is presented as an additional demonstration. This work lays the foundation for development of more robust and flexible Bayesian estimation methods that will greatly enhance the utility of this and similar models.
To control the global HIV epidemic, targeted interventions to reduce the incidence of HIV infections are urgently needed until an effective HIV vaccine is available. This study describes HIV-1 incidence and associated risk factors in a general population cohort of adults from Mbeya region, Tanzania, who participated in a vaccine preparedness study.
We conducted a closed prospective cohort study with 6-monthly follow-up from 2002 to 2006 enrolling adults from the general population. HIV-1 incidence and risk factors for HIV-1 acquisition were analyzed using Cox regression.
We observed 2578 seronegative participants for a mean period of 3.06 person years (PY) (7471 PY in total). Overall HIV-1 incidence was 1.35 per 100 PY (95% confidence interval [CI], 1.10-1.64/100 PY). The highest overall HIV-1 incidence was found in females from Itende village (1.55 per 100 PY; 95% CI, 0.99-2.30/100 PY); the highest age-specific incidence was observed in semiurban males aged 30 to 34 years (2.75 per 100 PY; 95% CI, 0.75-7.04). HIV-1 acquisition was independently associated with female gender (hazard ratio [HR], 1.64; 95% CI, 1.05-2.57), younger age at enrollment (age 18-19 versus 35-39 years: HR, 0.29; 95% CI, 0.11-0.75), alcohol consumption (almost daily versus none: HR, 2.01; 95% CI, 1.00-4.07), education level (secondary school versus none: HR, 0.39; 95% CI, 0.17-0.89), and number of lifetime sex partners (more than five versus one: HR, 2.22; 95% CI, 1.13-4.36).
A high incidence of HIV was observed in this cohort, and incident infection was strongly associated with young age, alcohol consumption, low school education level, and number of sex partners. Targeted interventions are needed to address the elevated risk associated with these factors.
This paper presents unique evidence that orphanhood matters in the long-run for health and education outcomes, in a region of Northwestern Tanzania. We study a sample of 718 nonorphaned children surveyed in 1991-94, who were traced and reinterviewed as adults in 2004. A large proportion, 19 percent, lost one or more parents before the age of 15 in this period, allowing us to assess permanent health and education impacts of orphanhood. In the analysis, we can control for a wide range of child and adult characteristics before orphanhood, as well as community fixed effects. We find that maternal orphanhood has a permanent adverse impact of 2 cm of final height attainment and one year of educational attainment. Expressing welfare in terms of consumption expenditure, the result is a gap of 8.5 percent compared to similar children whose mother survived till at least their 15th birthday.
To assess changes in HIV incidence and prevalence in Caió, a rural area of Guinea-Bissau, between 1990 and 2007.
Three cross-sectional community surveys.
In 1990, 1997, and 2007, surveys were conducted among adults. The prevalence of HIV-1 and of HIV-2 was estimated for each survey, and incidence rates were calculated for the first (1990-1997) and second period (1997-2007).
The HIV-1 incidence was approximately 4.5/1000 person-years in the two periods, whereas the HIV-2 incidence decreased from 4.7 (95% confidence interval 3.6-6.2) in the first to 2.0 (95% confidence interval 1.4-3.0) per 1000 person-years in the second period (P < 0.001). HIV-1 prevalence rose from 0.5% in 1990 to 3.6% in 2007, and HIV-2 prevalence decreased from 8.3% in 1990 to 4.7% in 2007. HIV-1 prevalence was less than 2% in 15 to 24 year olds in all surveys and was highest (7.2%) in 2007 among 45 to 54 year olds. The HIV-2 prevalence was fivefold higher in older subjects (> or =45 yr) compared with those less than 45 years in both sexes in 2007.
HIV-1 incidence is stable, and its prevalence is increasing, whereas HIV-2 incidence and prevalence are both declining. In contrast with what has been observed in other sub-Saharan countries, HIV-1 prevalence is lower in younger age groups than older age groups.
This article uses a 13-year panel of individuals in Tanzania to assess how adult mortality shocks affect both the short- and long-run consumption growth of surviving household members. Using unique data that tracks individuals from 1991 to 2004, we examine consumption growth, controlling for a set of initial community, household, and individual characteristics; the effect is identified using the sample of households in 2004 that grew out of baseline households. We find robust evidence that an affected household will see consumption drop 7% within the first 5 years after the adult death. With high growth in the sample over this time period, this creates a 19 percentage point growth gap with the average household. There is some evidence of persistent effects of these shocks for up to 13 years, but these effects are imprecisely estimated and not significantly different from zero. The impact of female adult death is found to be particularly severe.
This paper presents unique evidence that orphanhood matters in the long run for health and education outcomes, in a region of Northwestern Tanzania. The paper studies a sample of 718 non-orphaned children surveyed in 1991-94, who were traced and re-interviewed as adults in 2004. A large proportion, 19 percent, lost one or more parents before the age of 15 in this period, allowing the authors to assess the permanent health and education impacts of orphanhood. The analysis controls for a wide range of child and adult characteristics before orphanhood, as well as community fixed effects. The findings show that maternal orphanhood has a permanent adverse impact of 2 cm of final height attainment and one year of educational attainment. Expressing welfare in terms of consumption expenditure, the result is a gap of 8.5 percent compared with similar children whose mother survived till at least their 15th birthday.
In sub-Saharan Africa, the prevalence of orphanhood among children has been greatly exacerbated by the HIV/AIDS pandemic. If orphanhood harms a child's development and these effects perpetuate into adult life, then the African orphan crisis could seriously jeopardize the continent's future generations. Whether or not there exists an adverse, causal and intergenerational effect of HIV/AIDS on development is of crucial importance for setting medical priorities. This study is the first to empirically investigate the impact of orphanhood on health and schooling using long-term longitudinal data following children into adulthood.
We examined a cohort of 718 children interviewed in the early 1990s and again in 2004. Detailed survey questionnaires and anthropometric measurements were administered at baseline and during a follow-up survey. Final attained height and education (at adulthood) between children who lost a parent before the age of 15 and those who did not were compared.
On average, children who lose their mother before the age of 15 suffer a deficit of around 2 cm in final attained height (mean 1.96; 95% CI 0.06-3.77) and 1 year of final attained schooling (mean 1.01; 95% CI 0.39-1.81). This effect is permanent and the hypothesis that it is causal cannot be rejected by our study. Although father's death is a predictor of lower height and schooling as well, we reject the hypothesis of a causal link.
The African orphan crisis, exacerbated by the HIV/AIDS epidemic will have important negative intergenerational effects.
Previous studies found educated individuals to have higher risk of human immunodeficiency virus (HIV)-1 infection in Africa. A reverse in this association was predicted. We investigated the change in this association from 1991 to 2005 in a rural population in Tanzania.
Two cross-sectional surveys were conducted in 1991(N = 1,152, response rate 76.4%) and 2005 (N = 1,528, 73.0%). Consenting individuals aged 15 to 44 years living in Oria village were interviewed and gave blood for HIV-1 testing.
Primary [adjusted odds ratio (AOR), 2.7; 95% confidence interval (CI): 1.3-20.0] and secondary/higher education (AOR, 4.5; 95% CI: 1.4-24.9) were associated with increased risk of HIV-1 infection in 1991. A reversed association was observed in 2005 where reduced odds of infection were associated with primary (AOR, 0.5; 95% CI: 0.2-0.8) and secondary/higher education (AOR, 0.4; 95% CI: 0.3-0.9). This was most pronounced among educated men. Corresponding reduction in risk behaviors were observed. Increased odds of reporting ever use of condom (AOR, 2.8; 95% CI: 1.1-7.3) and 70% reduction in reporting >or=2 sexual partners in the past year was observed among educated women. Educated men reported 60% reduction in the odds of reporting >or=2 sexual partners in the past month preceding the last survey.
A reversed association between education attainment and HIV-1 infection was observed in this population between 1991 and 2005. Education seems to have an empowering role in women. Decreased risk among educated men may have an impact on HIV-1 transmission. Improving education sector in rural areas might be instrumental in the fight against the HIV epidemic.
To assess the trend in HIV-1 seroprevalence in an adult population in Uganda.
An observational cohort study with four year follow up.
A cluster of 15 villages in rural Uganda.
All residents of the 15 villages--about 10,000 people.
Prevalence of HIV-1 infection as assessed by enzyme immunoassay.
During the five year period the overall standardised seroprevalence of HIV-1 showed little change; 8.2% in 1990, 7.6% in 1994. Among males aged 13-24 years the prevalence decreased from 3.4% to 1.0% (P for trend < 0.001); among females of the same age the corresponding values were 9.9% and 7.3%. The decrease was greatest in males aged 20-24 years and females aged 13-19 years.
This is the first report of a decline in HIV-1 prevalence among young adults in a general population in sub-Saharan Africa with high overall HIV-1 prevalence. It is too early to conclude that the epidemic in this population is in decline, but the results of this study should be reason for some cautious optimism and encourage the vigorous pursuit of AIDS control measures.
Major interventions to reduce HIV transmission involve increasing knowledge about preventing HIV transmission for sustained behavioral changes; and enhancing the control of sexually transmitted diseases (STD), which increase the probability of HIV transmission. Activities have also been developed to prevent the transmission of HIV by blood, donor selection, and more rational use of transfusions. Behavioral changes among injecting drug users have also been promoted. Recommendations are made for the evaluation of AIDS programs, focusing on prevention of sexual transmission of HIV, and outlining the approach developed by the Global Program on AIDS (GPA; Geneva, Switzerland) for use by national programs. Based on the feasibility, accuracy, reliability and validity of the quantitative assessment of programs, 10 indicators of progress and outcomes of prevention activities have been developed by GPA. These include indicators of population knowledge regarding preventive practices, reported sexual behavior and use of condoms in the general population, STD service evaluation, and indicators of program impact. The latter are measured through the reported STD incidence in the general male population, and syphilis and HIV prevalence in women. The four methods are proposed for measuring the 10 core prevention indicators (PI). Five PIs are measured during a population survey: reported knowledge of preventive practices (PI-1), condom availability at peripheral level (PI-3), reported frequency of nonregular sexual partners (PI-4), reported condom use during nonregular sexual encounters (PI-5), and reported STD incidence among men (PI-9). Condom availability at central level (PI-2) is assessed through key-informant interviews with major distributors. Structured health facility surveys allow assessment of the appropriateness of STD case management (PI-6 and PI-7). A serosurvey among antenatal clinic attenders aged 15-24 years allows the measurement of HIV and syphilis seroprevalence in that population (PI-8 and PI-10). GPA recommends that such surveys be repeated after a period of 1 to several years.
Routine surveillance of HIV (human immunodeficiency virus) infection and AIDS has been established over the past decade in many countries around the world. HIV estimates derived from empirical data are essential to the assessment of the HIV situation in different parts of the world and trends are used in tracking the development of regional epidemics, thereby keeping intervention activities focused on realities. As of the end of 1995, and following an extensive country-by-country review of HIV/AIDS data, a cumulative total of 6 million AIDS cases were estimated to have occurred in adults and children worldwide and currently 20.1 million adults are estimated to be alive and infected with HIV or have AIDS. Of the total prevalent HIV infections, the majority remain concentrated in eastern, central and southern Africa, but the epidemic is evolving with spread of infection from urban to rural areas, as well as to West and South Africa, India and South-east Asia, and to a lesser extent--with proportional shifts to heterosexual infections--in North America, western Europe and Latin America. While the longer-term dimensions of the HIV epidemic at global level cannot be forecast with confidence, WHO currently projects a cumulative total of close to 40 million HIV infections in men, women and children by the year 2000. By that time, the male:female ratio of new infections will be close to 1:1. Recent trends indicate that HIV prevalence levels may be stabilizing or even decreasing among pregnant women in southern Zaire and parts of Uganda, among military recruits aged 21 in Thailand, and in some populations of northern Europe and the USA. While these changes may take place as part of the intrinsic dynamic of the epidemic, there is some evidence that declines in HIV prevalence are related to declines in HIV incidence which are, at least partly, due to prevention efforts. The challenge of surveillance and evaluation methods is now to identify the ingredients of success which may reveal a glimmer of hope.
To examine trends in HIV prevalence and behaviours in Zambia during the 1990s.
The core Zambian system for epidemiological surveillance and research has two major components: (i) HIV sentinel surveillance at selected antenatal clinics (ANC) in all provinces; and (ii) population-based HIV surveys in selected sentinel populations (1996 and 1999). The former was refined in 1994 to improve the monitoring of prevalence trends, whereas the latter was designed to validate ANC-based data, to study change in prevalence and behaviour concomitantly and to assess demographic impacts.
The ANC-based data showed a dominant trend of significant declines in HIV prevalence in the 15--19 years age-group, and for urban sites also in age-group 20--24 years and overall when rates were adjusted for over-representation of women with low education. In the general population prevalence declined significantly in urban women aged 15--29 years whereas it showed a tendency to decline among rural women aged 15-24 years. Prominent decline in prevalence was associated with higher education, stable or rising prevalence with low education. There was evidence in urban populations of increased condom use, decline in multiple sexual partners and, among younger women, delayed age at first birth.
The results suggested a dominant declining trend in HIV prevalence that corresponds to declines in incidence since the early 1990s attributable to behavioural changes. Efforts to sustain the ongoing process of change in the well-educated segments of the population should not be undervalued, but the modest change in behaviour identified among the most deprived groups represents the major preventive challenge.
For more than a decade, most experts have assumed that more than 90% of HIV in African adults results from heterosexual transmission. In this exercise, we show how data from studies of risk factors for HIV can be used to estimate the proportion from sexual transmission, and we present our estimates.
Calculating two ways from available data, our two point estimates — we do not estimate confidence intervals — are that 25-29% of HIV incidence in African women and 30-35% in men is attributable to sexual transmission; these estimates assume 10% annual epidemic growth. These findings call for reconceptualization of research to more accurately assess routes of HIV transmission.
Objective.
—To determine the sociodemographic and behavioral risk factors associated with human immunodeficiency virus (HIV) infection in two cohorts of young men selected for military service in northern Thailand.Design.
—Military conscripts were studied cross-sectionally after conscription in May 1991 and November 1991. Risk factors were assessed by interview with trained nonmilitary interviewers.Setting.
—Two military training bases in Chiang Mai, Thailand.Participants.
—A total of 2417 young men aged 19 to 23 years (mean age, 21 years) conscripted by lottery into military service in the Royal Thai Army or Royal Thai Air Force from six provinces in northern Thailand.Main Outcome Measures.
—Human immunodeficiency virus seroprevalence by enzyme-linked immunosorbent assay confirmed by Western blot and univariate and multivariate analyses of sociodemographic and behavioral risk factors associated with HIV seroprevalence.Results.
—Overall, 289 (12.0%) of 2417 men were HIV-seropositive at baseline. The strongest associations with being HIV positive were heterosexual activities. History of sex with a female commercial sex worker (CSW) was frequent (96.5% of men who were HIV-positive and 79.0% of men who were HIV-negative) and strongly associated with HIV infection on univariate and multivariate analyses (adjusted odds ratio, 1.60 to 2.07, depending on the frequency of CSW contact). Also, sexually transmitted diseases were common and associated with HIV infection in both univariate and multivariate analyses (adjusted odds ratio, 3.36). Sex with other males and injection drug use were uncommon and not associated with HIV infection. Condom use was reported in 61.5% of men at last sex with a CSW but was not shown to be protective of prevalent HIV infection.Conclusion.
—The epidemic of HIV infection has spread widely among young men in northern Thailand, despite reported frequent and recent use of condoms during sex with female CSWs. Control of HIV infection in this population will probably require more regular and effective use of condoms, prevention and treatment of sexually transmitted diseases, and reduction in the frequency of CSW contact.(JAMA. 1993;270:955-960)
Objective: To describe the trends in HIV transmission and sexual behaviour in a rural population in Africa. Design: An open community cohort study with demographic surveillance and surveys of all consenting adults. Methods: All residing adults aged 15–44 years who participated in surveys in 1994–1995, 1996–1997 and 1999–2000 were tested for HIV infection and provided information on sexual behaviour. The district AIDS control programme was the only intervention. Result: The prevalence of HIV among adults aged 15–44 years increased gradually from 5.9% in 1994–1995 to 6.6% in 1996–1997 and 8.1% in 1999–2000. The incidence of HIV increased from 0.8 to 1.3 per 100 person-years during 1994–1997 and 1997–2000, respectively. In spite of a modest increase in knowledge during the study period, most individuals continued to feel that they were not at risk of HIV, and sexual risk behaviour remained largely unchanged, except for a small increase in condom use. HIV transmission levels continued to be higher in the trading centre than in the nearby rural villages within this small geographical area, although differences became smaller over time. Conclusion: The gradual and continuing spread of HIV and the striking lack of change in sexual behaviour in this rural population suggest that the low-cost district intervention package does not appear to be adequate to stem the growth of the epidemic, and more intensive AIDS control efforts are needed.
The results of a population-based follow-up study are presented. The baseline study which started in August 1987, was carried out to determine the prevalence of human immunodeficiency virus (HIV-1) infection in the Kagera region of Tanzania. A multistage cluster sampling technique was adopted in the selection of the study population. In the follow-up survey which started in June 1988, members of the same study population were revisited and studied in order to determine the incidence of HIV-1 infection among those who were HIV seronegative in the initial survey. HIV serology was conducted by using enzyme-linked immunosorbent assay and all positive sera were confirmed by the Western blot technique. A total population of 1316 adults aged 15-54 years was studied, constituting an average follow-up response rate of 69% in the rural areas and of 59% in the urban area. The overall incidence of HIV-1 infection among the adult population sample was 13.7 per 1000 person-years at risk with the highest incidence in the urban zone (47.5 per 1000 person-years at risk) and the lowest incidence in one of the three rural zones (4.9 per 1000 person-years at risk). The age-specific annual incidence was highest in the age group 25-34 years for males and in the age group 15-24 for females. From these results it was estimated that the number of newly infected adults in the region each year is about 8200 with a range between 5400 and 11 000 corresponding to the 95% confidence limits on the overall incidence. This observation indicates a serious level of continued transmission of HIV-1 infection in the region. It therefore calls for more intensified control measures against the epidemic at all levels in the country since a similar picture may exist in the other regions.
To assess trends over the last 12 years in HIV-1/HIV-2 seroprevalence among blood donors in African nations and to correlate trends with national AIDS policies, with the purpose of preventing future cases.
Using collated data of African seroepidemiologic studies published by the U.S. Bureau of the Census, we established a best-fit linear trend, determined by regression analysis of HIV-1 and HIV-2 seroprevalence values for African blood donors against time, with adjustments for sample size of reported studies.
Among 38 nations with sufficient data, 11 showed increases in HIV-1 seroprevalence, six showed decreases and 21 showed no significant changes. Decreases were seen primarily in nations with a high HIV-1 seroprevalence before 1989 (P<0.001, Chi-square). HIV-2 seroprevalence decreased in all nations where it was tested except Nigeria. There was a moderate correlation between decreases in HIV-1 and HIV-2 seroprevalence values (correlation coefficient = 0.39). No significant correlations between HIV policies and subsequent HIV-1 seroprevalence trends among blood donors and HIV patients were detected.
A great disparity exists in trends in HIV-1 seroprevalence among African nations. HIV-2 seroprevalence is consistently decreasing throughout most of West Africa, the exception being Nigeria. The absence of any significant correlation between HIV seroprevalence trends and healthcare policies suggests that other factors are more influential than national policy in determining such trends and, by extrapolation, trends in AIDS prevalence.
After the recognition of AIDS (acquired immunodeficiency syndrome) in the early 1980s, uncertainty about the present and future dimensions of HIV (human immunodeficiency virus) infection led to the development of many models to estimate current and future numbers of HIV infections and AIDS cases. The Global Programme on AIDS (GPA) of the World Health Organization (WHO) has developed an AIDS projection model which relies on available HIV seroprevalence data and on the annual rate of progression from HIV infection to AIDS for use in areas where reporting of AIDS cases is incomplete, and where scant data are available to quantify biological and human behavioural variables. Virtually all models, including the WHO model, have projected large increases in the number of AIDS cases by the early 1990s. Such short-term projections are considered relatively reliable since most of the new AIDS cases will develop in persons already infected with HIV. Longer-term prediction (10 years or longer) is less reliable because HIV prevalence and future trends are determined by many variables, most of which are still not well understood. WHO has now applied the Delphi method to project HIV prevalence from the year 1988 to mid-2000. This method attempts to improve the quality of the judgements and estimates for relatively uncertain issues by the systematic use of knowledgeable "experts". The mean value of the Delphi projections for HIV prevalence in the year 2000 is between 3 and 4 times the 1988 base estimate of 5.1 million; these projections have been used to obtain annual estimates of adult AIDS cases up to the year 2000. Coordinated HIV/AIDS prevention and control programmes are considered by the Delphi participants to be potentially capable of preventing almost half of the new HIV infections that would otherwise occur between 1988 and the year 2000. However, more than half of the approximately 5 million AIDS cases which are projected for the next decade will occur despite the most rigorous and effective HIV/AIDS prevention efforts since these AIDS cases will develop in persons whose HIV infection was acquired prior to 1989. The Delphi projections of HIV infection and AIDS cases derived from the WHO projection model need to be periodically reviewed and modified as additional data become available. These projections should be viewed as the first of many attempts to develop estimates for planning strategies to combat the HIV/AIDS pandemic in the 1990s.
A population-based survey was carried out in the Kagera region of the United Republic of Tanzania in 1987 to determine the magnitude of HIV-1 infection and to study associated risk factors. The region was divided into one urban and three rural zones. A multistage cluster sampling technique was adopted. Antibodies to HIV-1 were determined by enzyme-linked immunosorbent assay and confirmed by Western blot analysis. A total of 2,475 adults (aged 15-54 years) and 1,961 children (aged 0-14 years) was studied. The overall prevalence of HIV-1 infection among adults was 9.6%, with a higher prevalence in the urban zone (24.2%) than in the three rural zones (10.0, 4.5 and 0.4%, respectively). The corresponding figures for children were 1.3% overall: 3.9% in the urban area and for the rural areas 1.2, 0.8 and 0.0%, respectively. The age-specific seroprevalence for adults was highest in the age group 25-34 years. The age-standardized sex-specific prevalence was higher among women than men in the urban zone, while it was the same in the rural zones. Change of sexual partners among adults was associated with an increased risk of HIV-1 seropositivity. Travelling outside the region but within the country was also found to be associated with increased risk of HIV-1 infection but only in the rural population.
To determine the sociodemographic and behavioral risk factors associated with human immunodeficiency virus (HIV) infection in two cohorts of young men selected for military service in northern Thailand.
Military conscripts were studied cross-sectionally after conscription in May 1991 and November 1991. Risk factors were assessed by interview with trained nonmilitary interviewers.
Two military training bases in Chiang Mai, Thailand.
A total of 2417 young men aged 19 to 23 years (mean age, 21 years) conscripted by lottery into military service in the Royal Thai Army or Royal Thai Air Force from six provinces in northern Thailand.
Human immunodeficiency virus seroprevalence by enzyme-linked immunosorbent assay confirmed by Western blot and univariate and multivariate analyses of sociodemographic and behavioral risk factors associated with HIV seroprevalence.
Overall, 289 (12.0%) of 2417 men were HIV-seropositive at baseline. The strongest associations with being HIV positive were heterosexual activities. History of sex with a female commercial sex worker (CSW) was frequent (96.5% of men who were HIV-positive and 79.0% of men who were HIV-negative) and strongly associated with HIV infection on univariate and multivariate analyses (adjusted odds ratio, 1.60 to 2.07, depending on the frequency of CSW contact). Also, sexually transmitted diseases were common and associated with HIV infection in both univariate and multivariate analyses (adjusted odds ratio, 3.36). Sex with other males and injection drug use were uncommon and not associated with HIV infection. Condom use was reported in 61.5% of men at last sex with a CSW but was not shown to be protective of prevalent HIV infection.
The epidemic of HIV infection has spread widely among young men in northern Thailand, despite reported frequent and recent use of condoms during sex with female CSWs. Control of HIV infection in this population will probably require more regular and effective use of condoms, prevention and treatment of sexually transmitted diseases, and reduction in the frequency of CSW contact.
The results of a population-based follow-up study are presented. The baseline study which started in August 1987, was carried out to determine the prevalence of human immunodeficiency virus (HIV-1) infection in the Kagera region of Tanzania. A multistage cluster sampling technique was adopted in the selection of the study population. In the follow-up survey which started in June 1988, members of the same study population were revisited and studied in order to determine the incidence of HIV-1 infection among those who were HIV seronegative in the initial survey. HIV serology was conducted by using enzyme-linked immunosorbent assay and all positive sera were confirmed by the Western blot technique. A total population of 1316 adults aged 15-54 years was studied, constituting an average follow-up response rate of 69% in the rural areas and of 59% in the urban area. The overall incidence of HIV-1 infection among the adult population sample was 13.7 per 1000 person-years at risk with the highest incidence in the urban zone (47.5 per 1000 person-years at risk) and the lowest incidence in one of the three rural zones (4.9 per 1000 person-years at risk). The age-specific annual incidence was highest in the age group 25-34 years for males and in the age group 15-24 for females. From these results it was estimated that the number of newly infected adults in the region each year is about 8200 with a range between 5400 and 11,000 corresponding to the 95% confidence limits on the overall incidence.(ABSTRACT TRUNCATED AT 250 WORDS)
The spread of the human immunodeficiency virus (HIV) and the resulting morbidity and mortality are major public health challenges with adverse social and economic implications. The pregnant population serves as an important marker of the extent of the problem in the sexually active low risk categorized population. Furthermore, a high HIV prevalence among women of childbearing age contributes to neonatal and infant mortality through perinatal transmission and also a large number of uninfected children become orphans. The objective of the present study was to determine the HIV prevalence rate and the risk factors in pregnant women attending antenatal care clinics in the Greater Harare area of Zimbabwe. Women presenting for antenatal care in four maternity clinics between May 1994 and June 1995 were tested for HIV-1 and HIV-2 antibodies following informed consent, counselling and completion of a questionnaire. Of the 1.168 women, 30.4 pc tested HIV-1 positive, with prevalence rates ranging from 23.6 pc at a lower density clinic, 28.6 pc in a medium density clinic, 30.7 pc in a higher density clinic and 33.2 pc at the referral maternity hospital. HIV-2 was present in 7.6 pc of the women. The 20 to 29 years age group had the highest HIV prevalence of 35 pc, (Odds Ratio (OR) = 2.4; 95 pc CI-1.33 to 4.32). Single pregnant women were more likely to test positive, (OR = 2.1; 95 pc CI = 1.2 to 3.7). Thirty five pc of the women reported previous use of condoms and in those where condom use was reported in casual relationships, there was a higher risk of HIV (OR 6.1; 95 pc CI = 2.1 to 17.3). Reported use of intravaginal herbs was associated with HIV risk (OR 1.4; 95 pc CI = 1.1 to 1.8; p < 0.03). History of genital ulcer (OR = 2.3), discharge (OR = 2.4), rash (OR = 2.7), genital ulcer with PID (OR = 5.8) was significantly associated with HIV infection. Present findings indicate a 30.4 pc HIV prevalence rate for a sample of 1,168 pregnant women in Harare. This rate is much higher than the 18 pc HIV prevalence rate reported for 1,008 pregnant women in the same Greater Harare area in 1990. We conclude that there is need for further innovative and aggressive community based as well as institutional interventions aimed at reducing HIV risk. Prevention strategies should include a wide range of socially contextualized initiatives.
To assess whether trends in serial HIV-1 prevalence reflect trend in HIV incidence, and to decompose the effects of HIV-1 incidence, mortality, mobility and compliance on HIV-1 prevalence in a population-based cohort.
Two-year follow up (1990-1992) of an open cohort of all adults aged 15-59 years, resident in a sample of 31 representative community clusters in rural Rakai District, Uganda.
A detailed household enumeration was concluded at baseline and in each subsequent year. All household residents were listed, and all deaths and in- and out-migrations that occurred in the intersurvey year wee recorded. In each year, all consenting adults were interviewed and provided a serological sample; 2591 adults aged 15-59 years were enrolled at baseline.
HIV prevalence among adults declined significantly 1990 and 1992 (23.4% at baseline, 21.8% in 1991, 20.9% in 1992; P < 0.05). Declining prevalence was also observed in subgroups, including young adults aged 15-24 years (from 20.6 to 16.2% over 3 years; P < 0.02), women of reproductive age (from 27.1 to 23.5%; P < 0.05), and pregnant women (from 25.4 to 20.0%; not significant), However, HIV incidence did not change significantly among all adults aged 15-59 years (2.1 +/- 0.4 per 100 person-years of observation (PYO) in 1990-1991 and 2.0 +/- 0.3 per 100 PYO in 1991-1992], nor in population subgroups. HIV-related mortality was high (13.5 per 100 PYO among the HIV-positive), removing more infected persons that were added by seroconversion. Net out-migration also removed substantial numbers of HIV-positive individuals.
In this mature HIV epidemic, HIV prevalence declined in the presence of stable and incidence. HIV-related mortality contributed most to the prevalence decline. Prevalence was not an adequate surrogate measure of incidence, limiting the utility or serial prevalence measures in assessing the dynamics of the HIV epidemic and in evaluating the impact of current preventive strategies.
In northwestern Tanzania, a population-based survey of HIV-1 infection in the Kagera region in 1987 demonstrated a high prevalence (24.2%) in adults of Bukoba town, whereas it was lower (10.0%) in the surrounding rural district of Bukoba. In 1993 and 1996, population-based cross-sectional studies were carried out in urban and rural Bukoba districts, respectively, to monitor the time trend in the prevalence of HIV-1 infection in the region. In both studies, a multistage cluster sampling technique was adopted in selecting study individuals. Consenting individuals between 15 and 54 years of age were interviewed using a structured questionnaire. Following individual counseling, blood samples were drawn and tested for HIV infection using enzyme-linked immunosorbent assay (ELISA) antibody detection tests. The overall age-adjusted HIV-1 seroprevalence in urban Bukoba decreased from 24.2% (134 of 553) in 1987 to 18.3% (118 of 653) in 1993 (p = .008). The age-adjusted gender-specific prevalence declined significantly in women, from 29.1% (95 of 325) to 18.7% (74 of 395; p = .0009). Except for men > or = 35 years of age, whose prevalence appeared to have an upward trend between the two studies, all other age groups in both genders had a downward trend; this finding was most significant in women between 15 and 24 years of age (from 27.6% to 11.2%; p = .0004). For the rural population, the overall prevalence decreased from 10.0% (54 of 538) in 1987 to 6.8% (118 of 1728) in 1996 (p = .01). Except for rural women between 15 and 24 years of age whose prevalence decreased from 9.7% (12 of 124) to 3.1% (12 of 383; p = .002), other age groups in the rural populations showed no change in prevalence. Ongoing interventions in this area leading to behavioral change may have contributed to this observation. An incidence study is under way to confirm this observation and to investigate the factors that are responsible for the decline in the HIV-1 prevalence.
To assess the present level of HIV-2 infection in an adult population in Bissau and to evaluate sex and age-specific changes in HIV-2 prevalence and incidence between 1987 and 1996.
Sex and age-specific changes in HIV-2 prevalence were evaluated comparing a survey from 1987 in a sample of 100 houses with a survey performed in 1996 in an independent sample of 212 houses from the same study area. HIV-2 incidence rates were examined in an adult population (age > or = 15 years) from 100 randomly selected houses followed with four consecutive HIV serosurveys from 1987 to 1996.
The HIV-2 prevalence in 1996 was 6.8% (men, 4.7%; women, 8.4%). Compared with the 1987 survey there was a significant decrease in prevalence among men [age-adjusted relative risk (RR), 0.50; 95% confidence interval (CI), 0.31-0.83], whereas it remained unchanged in women (RR, 1.00; 95% CI, 0.67-1.48). The male-to-female RR decreased from 0.99 (95% CI, 0.61-1.61) in 1987 to 0.51 (95% CI, 0.34-0.76) in 1996. The overall annual incidence rate was 0.54 per 100 person-years of observation (PYO), being higher in women (0.72 per 100 PYO) than in men (0.31 per 100 PYO). With the observation time divided into an early and a late period, there was a decrease in incidence with time among men (0.66 to 0.00 per 100 PYO), but no major change among women (0.59 to 0.85 per 100 PYO). The two trends differed significantly (P = 0.03). We observed a higher annual incidence rate amongst older women aged > 44 years (1.77 per 100 PYO) than among younger women (0.55 per 100 PYO; P = 0.05).
There are no signs of an epidemic spread of HIV-2 in Bissau even though the HIV-1 prevalence is increasing rapidly. A significant reduction in the male HIV-2 prevalence and incidence rates has resulted in a major shift in the pattern of spread of HIV-2, from being equally distributed to being predominantly a female infection. Currently, older women in particular seem to have a high risk of getting infected.
To monitor the HIV-1 epidemic in Western Uganda and the possible impact of interventions.
Results from sentinel surveillance of HIV-1 seroprevalence were compared with cross-sectional serosurvey data and model simulations.
Age-specific trends in HIV-1 prevalence between 1991 and 1997 amongst antenatal clinic (ANC) attenders in the town of Fort Portal, where a comprehensive AIDS control programme has been implemented since 1991, were analysed. Results were compared with outputs from a mathematical model simulating the HIV-1 epidemic in Uganda. Two scenarios were modelled: one without and one with behaviour change. Sentinel surveillance data were compared with data from a population-based HIV-1 serosurvey at the study site, which was carried out in early 1995.
Data from 3271 ANC attenders identified greater education and being single as risk factors for HIV-1 infection. A significant decrease of risk for women with secondary school education over time was observed, whereas the risk for illiterate women remained high. Among women aged 15-19 years (n = 1045) education and marital status-adjusted HIV-1 prevalence declined steadily from 32.2% in 1991 to 10.3% in 1997. For 20-24-year-old women (n = 1010) HIV-1 prevalence increased until 1993 from 19.9% to 31.7% and decreased thereafter (21.7% in 1997). These trends closely follow the prediction of the model simulation assuming behaviour change, and for 1995-1997, confidence intervals of the HIV-1 prevalence estimate exclude the model output for an uninfluenced epidemic. No clear trends of HIV-1 prevalence were found in older women (n = 1216) and comparisons with the model were ambiguous. Sentinel surveillance data at the time of the population survey closely reflected results for the female general population sample for the two younger age-groups (15-19 and 20-24 years). In contrast, pregnant women aged 25-29 years showed significantly lower rates than the population sample (20.8% versus 45.1%).
HIV-1 prevalence amongst ANC attenders aged 15-24 years can be used to monitor the HIV-1 epidemic in the given setting. Declining trends of HIV-1 prevalence in women aged 15-19 and 20-24 years most likely correspond to a reduced HIV-1 incidence attributable to changes in behaviour. Our data also show that sentinel surveillance data need to be age-stratified to give useful information.
To assess trends in HIV-1 infection rates and changes in sexual behaviour over 7 years in rural Uganda.
An adult cohort followed through eight medical-serological annual surveys since 1989-1990. All consenting participants gave a blood sample and were interviewed on sexual behaviour.
On average, 65% of residents gave a blood sample at each round. Overall HIV-1 prevalence declined from 8.2% at round 1 to 6.9% at round 8 (P = 0.008). Decline was most evident among men aged 20-24 years (11.7 to 3.6%; P < 0.001) and women aged 13-19 (4.4% to 1.4%; P = 0.003) and 20-24 (20.9% to 13.8%; P = 0.003). However, prevalence increased significantly among women aged 25-34 (13.1% to 16.6%; P = 0.04). Although overall incidence declined from 7.7/1000 person-years (PY) in 1990 to 4.6/1000 PY in 1996, neither this nor the age-sex specific rates changed significantly (P > 0.2). Age-standardized death rates for HIV-negative individuals were 6.5/1000 PY in 1990 and 8.2/1000 PY in 1996; corresponding rates for HIV-positive individuals were 129.7 and 102.7/1000 PY, respectively. There were no significant trends in age-adjusted death rates during follow-up for either group. There was evidence of behaviour change towards increase in condom use in males and females, marriage at later age for girls, later sexual debut for boys and a fall in fertility especially among unmarried teenagers.
This is the first general population cohort study showing overall long-term significant reduction in HIV prevalence and parallel evidence of sexual behaviour change. There are however no significant reductions in either HIV incidence or mortality.
Objective: To identify risk factors associated with HIV incidence in a rural Ugandan population. Design: Case-control study. Methods: Men and women who seroconverted between 1990 and 1997 (cases) and seronegative subjects (controls) were drawn from a general population cohort of approximately 5000 adults in rural, southwestern Uganda. Information on risk factors was ascertained through a detailed interview and physical examination by clinicians who were blind to the study subjects' HIV status. All patients were interviewed within 2 years of their estimated date of seroconversion. Results: Data were available on 130 men (37 cases, 93 controls) and 133 women (46 cases, 87 controls). There was a significantly higher risk of infection in men (odds ratio [OR], 6.51; 95% confidence interval [CI], 1.06-39.84) and women (OR, 4.75; 95% CI, 1.26-17.9) who were unmarried and in a steady relationship, and in men who were divorced, separated, or widowed (OR, 4.33; 95% CI, 1.32-14.25) compared with those who were married. There was a significantly higher risk of HIV infection in men (OR, 3.78; 95% CI, 1.20-11.93) and women (OR, 20.78; 95% CI, 2.94-141.2) who reported >=5 lifetime sexual partners compared with those who reported at most 1 partner. For men, there was an increased risk of infection associated with receiving increasing numbers of injections in the 6 months prior to interview (p < .001 for trend). Women reporting sex against their will in the year prior to interview were at higher risk of infection (OR, 7.84; 95% CI, 1.29-47.86,; p = .020). Conclusions: The strongest risk factor for HIV incidence in this rural Ugandan population is lifetime sexual partners. The increased risks found for women reporting coercive sex and men reporting injections require further investigation.
To measure prevalence and model incidence of HIV infection.
2013 consecutive pregnant women attending public sector antenatal clinics in 1997 in Hlabisa health district, South Africa. Historical seroprevalence data, 1992-1995.
Serum remaining from syphilis testing was tested anonymously for antibodies to HIV to determine seroprevalence. Two models, allowing for differential mortality between HIV-positive and HIV-negative people, were used. The first used serial seroprevalence data to estimate trends in annual incidence. The second, a maximum likelihood model, took account of changing force of infection and age-dependent risk of infection, to estimate age-specific HIV incidence in 1997. Multiple logistic regression provided adjusted odds ratios (OR) for risk factors for prevalent HIV infection.
Estimated annual HIV incidence increased from 4% in 1992/1993 to 10% in 1996/1997. In 1997, highest age-specific incidence was 16% among women aged between 20 and 24 years. In 1997, overall prevalence was 26% (95% confidence interval [CI], 24%-28%) and at 34% was highest among women aged between 20 and 24 years. Young age (<30 years; odds ratio [OR], 2.1; p = .001), unmarried status (OR 2.2; p = .001) and living in less remote parts of the district (OR 1.5; p = .002) were associated with HIV prevalence in univariate analysis. Associations were less strong in multivariate analysis. Partner's migration status was not associated with HIV infection. Substantial heterogeneity of HIV prevalence by clinic was observed (range 17%-31%; test for trend, p = .001).
This community is experiencing an explosive HIV epidemic. Young, single women in the more developed parts of the district would form an appropriate cohort to test, and benefit from, interventions such as vaginal microbicides and HIV vaccines.
To estimate HIV-1 prevalence among women attending an antenatal clinic in the Gulu District (North Uganda) and, based on these data, among the district's female population.
Anonymous HIV-1 screening was performed for 8555 antenatal clinic attendees aged 15-39 years in the period 1993-1997. The results were used to estimate the prevalence among the district's female population, accounting for differences in fertility rates by HIV-1 serostatus.
Among antenatal clinic attendees, HIV-1 prevalence showed a significant linear decrease (P < 0.001), from 26.0% in 1993 [95% confidence Interval (CI), 23.2-29.0%] to 16.1% in 1997 (95% CI, 14.8-17.5%). This decrease was mostly due to a marked decrease until 1995 (14.3%; 95% Cl, 12.7-16.0%) and was more pronounced among women aged under 30 years (P < 0.001), from both urban and rural areas (P < 0.001). The risk of being infected was higher among women from urban areas (Gulu Municipality), both over the entire period (adjusted prevalence proportion ratio = 1.54; 95% CI, 1.40-1.68) and by individual year. The estimated prevalence for the 15-39-year-old female population, standardized by age and area of residence, decreased from 25.4% in 1993-1994 to 17.8% in 1996-1997; these rates were 1.22 and 1.28 times higher, respectively, than those among antenatal clinic attendees.
The trend of decrease among young women, for whom changes in HIV-1 prevalence more closely reflect incidence, could be partially due to a reduction in risk behaviour and a consequent decreasing incidence. Differences in fertility rates by HIV-1 serostatus should be addressed when using antenatal clinic data to estimate prevalence among the general female population.
In Uganda, there have been encouraging reports of reductions in HIV-1 prevalence but not in incidence, which is the most reliable measure of epidemic trends. We describe HIV-1 incidence and prevalence trends in a rural population-based cohort between 1989 and 1999.
We surveyed the adult population of 15 neighbouring villages for HIV-1 infection using annual censuses, questionnaires, and serological surveys. We report crude annual incidence rates by calendar year and prevalence by survey round.
6566 HIV-1 seronegative adults were bled two or more times between January, 1990, and December, 1999, contributing 31984 person years at risk (PYAR) and 190 seroconversions. HIV-1 incidence fell from 8.0 to 5.2 per 1000 PYAR between 1990 and 1999 (p=0.002, chi(2) for trend). Significant sex-specific and age-group-specific reductions in incidence were evident. Incidence was 37% lower for 1995-99 than for 1990-94 (p=0.002, t-test). On average, 4642 adult residents had a definite HIV-1 serostatus at each yearly survey round. HIV-1 prevalence fell significantly between the first and tenth annual survey rounds (p=0.03, chi(2) for trend), especially among men aged 20-24 years (6.5% to 2.2%) and 25-29 years (15.2% to 10.9%) and women aged 13-19 years (2.8% to 0.9%) and 20-24 years (19.3% to 10.1%) (all p<0.001, chi(2) for trend).
Our findings of a significant drop in adult HIV-1 incidence in rural Ugandans give hope to AIDS control programmes elsewhere in sub-Saharan Africa where rates of HIV-1 infection remain high.
The objective of this study was to examine the epidemic trends of HIV-1 infection in a rural population cohort in Uganda followed for 10 years. The methods used were to assess incidence and prevalence trends in adults in this longitudinal cohort study. The results showed that incidence of infection has fallen significantly in all adults, and separately in males, females, young adults and older adults over the course of the study period. There was also a reduction in prevalence, especially in young men and women. There was some evidence of a cohort effect in women. The conclusions are that this study provides the first evidence of a falling incidence in a rural general population in Africa. This was an observational cohort exposed to national health education messages, giving hope that similar campaigns elsewhere in Africa could be used effectively in efforts to control the HIV epidemic.
To describe the trends in HIV transmission and sexual behaviour in a rural population in Africa.
An open community cohort study with demographic surveillance and surveys of all consenting adults.
All residing adults aged 15-44 years who participated in surveys in 1994-1995, 1996-1997 and 1999-2000 were tested for HIV infection and provided information on sexual behaviour. The district AIDS control programme was the only intervention.
The prevalence of HIV among adults aged 15-44 years increased gradually from 5.9% in 1994-1995 to 6.6% in 1996-1997 and 8.1% in 1999-2000. The incidence of HIV increased from 0.8 to 1.3 per 100 person-years during 1994-1997 and 1997-2000, respectively. In spite of a modest increase in knowledge during the study period, most individuals continued to feel that they were not at risk of HIV, and sexual risk behaviour remained largely unchanged, except for a small increase in condom use. HIV transmission levels continued to be higher in the trading centre than in the nearby rural villages within this small geographical area, although differences became smaller over time.
The gradual and continuing spread of HIV and the striking lack of change in sexual behaviour in this rural population suggest that the low-cost district intervention package does not appear to be adequate to stem the growth of the epidemic, and more intensive AIDS control efforts are needed.
This paper is a follow-up of earlier findings by the Kagera AIDS Research Project (KARP), which documented declining trends in the prevalence and incidence of HIV infection in the Kagera region of Tanzania. The paper examines socio-cultural and sexual behavioral changes as possible determinants of the observed declining trends in Bukoba, the largest urban area of the region. The study used in-depth interviews, focus group discussions, field observations and ethnographic assessments to collect the required data. The findings suggest that since the initial years of the epidemic there have been significant changes in sexual behaviors, norms, values, and customs that are considered high-risk for HIV transmission. The findings show an increase in condom use, abstinence, zero grazing (sticking to one sexual partner) and uptake of voluntary HIV testing while traditional practices such as polygamy, widow inheritance, excessive alcohol consumption, and sexual networking are declining. We suggest that these changes are partly a result of the severity of the epidemic itself in the study area, and interventions that have been carried out in this area since 1987. The major interventions have included health education, the distribution of condoms, AIDS education in schools, voluntary HIV counseling and testing. These are encouraging findings that give hope and we believe that other places within Tanzania and other countries experiencing a severe AIDS crisis have much to learn from this experience. However, changes in norms and behavior are vulnerable; people in Kagera are still at risk and there is a need for continued intervention together with monitoring of the direction of the epidemic.
During the past year, a group has argued that unsafe injections are a major if not the main mode of HIV-1 transmission in sub-Saharan Africa. We review the main arguments used to question the epidemiological interpretations on the lead role of unsafe sex in HIV-1 transmission, and conclude there is no compelling evidence that unsafe injections are a predominant mode of HIV-1 transmission in sub-Saharan Africa. Conversely, though there is a clear need to eliminate all unsafe injections, epidemiological evidence indicates that sexual transmission continues to be by far the major mode of spread of HIV-1 in the region. Increased efforts are needed to reduce sexual transmission of HIV-1.
Monitoring of HIV-1 infection prevalence and trends in the general population using pregnant women as a sentinel population: 9 years experience from the Kagera region of Tanzania.
- Kwesigabo
High HIV incidence and prevalence among young women in rural South Africa: developing a cohort for intervention trials.
- Wilkinson