[show abstract][hide abstract] ABSTRACT: Objective. To compare maternal morbidity in HIV-infected and uninfected pregnant women. Methods. Major maternal morbidity (severe febrile illness, illnesses requiring hospital admissions, surgical revisions, or illnesses resulting in death) was measured prospectively in a cohort of HIV-infected and uninfected women followed from 36 weeks of pregnancy to 6 weeks after delivery. Odds ratios of major morbidity and associated factors were examined using logistic regression. Results. Major morbidity was observed in 46/129 (36%) and 104/390 (27%) of the HIV-infected and HIV-uninfected women, respectively, who remained in followup. In the multivariable analysis, major morbidity was independently associated with HIV infection, adjusted odds ratio (AOR) 1.7 (1.1 to 2.7), nulliparity (AOR 2.0 (1.3 to 3.0)), and lack of, or minimal, formal education (AOR 2.1 (1.1 to 3.8)). Conclusions. HIV was associated with a 70% increase in the odds of major maternal morbidity in these Ugandan mothers.
[show abstract][hide abstract] ABSTRACT: Given the well documented occurrence of immune reconstitution inflammatory syndrome (IRIS) in HIV-infected patients who recently started combination antiretroviral therapy (cART), we examined whether cART initiation increased the risk of Kaposi sarcoma and non-Hodgkin lymphoma (NHL) using data from the Concerted Action on SeroConversion to AIDS and Death in Europe (CASCADE) collaboration.
A nested matched case-control study design was used to assess the effects of individual CD4 cell trajectories and exposure to cART close to the time of cancer diagnosis.
Cases were patients diagnosed with either cancer during follow-up with a minimum of two consecutive CD4 cell readings within the year preceding diagnosis. For each case, up to 10 controls, matched by sex and cohort, were selected by random sampling. Changes in CD4 cell count, calculated by simple and piecewise linear regression, and recent exposure to cART were compared within matched case-control sets using conditional logistic regression.
Using data on 689 cases and 4588 controls, we found that an initially low and decreasing CD4 cell count during the year prior to cancer diagnosis is predictive of both Kaposi sarcoma and NHL. Most of this cancer risk is explained by the immunodeficiency characteristic of the period before cART initiation; however, an increased cancer risk was seen in patients who initiated cART in the previous 3 months (odds ratio 2.31; 95% confidence interval 1.33, 4.00).
Although IRIS may transiently increase the risk of Kaposi sarcoma or NHL in HIV-infected patients, the timely initiation of cART remains the best strategy to avoid the development of these malignancies.
AIDS (London, England) 05/2011; 25(11):1395-403. · 4.91 Impact Factor
[show abstract][hide abstract] ABSTRACT: The impact of infection with HIV on the risk of cancer in children is uncertain, particularly for those living in sub-Saharan Africa. In an ongoing study in a paediatric oncology centre in Malawi, children (aged </= 15 years) with known or suspected cancers are being recruited and tested for HIV and their mothers or carers interviewed. This study reports findings for children recruited between 2005 and 2008.
Only children with a cancer diagnosis were included. Odds ratios (OR) for being HIV positive were estimated for each cancer type (with adjustment for age (<5 years, >/= 5 years) and sex) using children with other cancers and non-malignant conditions as a comparison group (excluding the known HIV-associated cancers, Kaposi sarcoma and lymphomas, as well as children with other haematological malignancies or with confirmed non-cancer diagnoses).
Of the 586 children recruited, 541 (92%) met the inclusion criteria and 525 (97%) were tested for HIV. Overall HIV seroprevalence was 10%. Infection with HIV was associated with Kaposi sarcoma (29 cases; OR = 93.5, 95% CI 26.9 to 324.4) and with non-Burkitt, non-Hodgkin lymphoma (33 cases; OR = 4.4, 95% CI 1.1 to 17.9) but not with Burkitt lymphoma (269 cases; OR = 2.2, 95% CI 0.8 to 6.4).
In this study, only Kaposi sarcoma and non-Burkitt, non-Hodgkin lymphoma were associated with HIV infection. The endemic form of Burkitt lymphoma, which is relatively frequent in Malawi, was not significantly associated with HIV. While the relatively small numbers of children with other cancers, together with possible limitations of diagnostic testing may limit our conclusions, the findings may suggest differences in the pathogenesis of HIV-related malignancies in different parts of the world.
[show abstract][hide abstract] ABSTRACT: To investigate any long term effects on mortality in participants in experimental research related to chemical warfare agents from 1941 to 1989.
Historical cohort study. Data sources Archive of UK government research facility at Porton Down, UK military personnel records, and national death and cancer records. Participants 18,276 male members of the UK armed forces who had spent one or more short periods (median 4 days between first and last test) at Porton Down and a comparison group of 17,600 non-Porton Down veterans followed to 31 December 2004.
Mortality rate ratio of Porton Down compared with non-Porton Down veterans and standardised mortality ratio of each veteran group compared with the general population. Both ratios adjusted for age group and calendar period.
Porton Down veterans were similar to non-Porton Down veterans in year of enlistment (median 1951) but had longer military service (median 6.2 v 5.0 years). After a median follow-up of 43 years, 40% (7306) of Porton Down and 39% (6900) of non-Porton Down veterans had died. All cause mortality was slightly greater in Porton Down veterans (rate ratio 1.06, 95% confidence interval 1.03 to 1.10, P<0.001), more so for deaths outside the UK (1.26, 1.09 to 1.46). Of 12 cause specific groups examined, rate ratios in Porton Down veterans were increased for deaths attributed to infectious and parasitic (1.57, 1.07 to 2.29), genitourinary (1.46, 1.04 to 2.04), circulatory (1.07, 1.01 to 1.12), and external (non-medical) (1.17, 1.00 to 1.37) causes and decreased for deaths attributed to in situ, benign, and unspecified neoplasms (0.60, 0.37 to 0.99). There was no clear relation between type of chemical exposure and cause specific mortality. The mortality in both groups of veterans was lower than that in the general population (standardised mortality ratio 0.88, 0.85 to 0.90; 0.82, 0.80 to 0.84).
Mortality was slightly higher in Porton Down than non-Porton Down veterans. With lack of information on other important factors, such as smoking or service overseas, it is not possible to attribute the small excess mortality to chemical exposures at Porton Down.
[show abstract][hide abstract] ABSTRACT: To determine cancer morbidity in members of the armed forces who took part in tests of chemical warfare agents from 1941 to 1989.
Historical cohort study, with cohort members followed up to December 2004.
Archive of UK government research facility at Porton Down, UK military personnel records, and national death and cancer records.
All veterans included in the cohort study of mortality, excluding those known to have died or been lost to follow-up before 1 January 1971 when the UK cancer registration system commenced: 17,013 male members of the UK armed forces who took part in tests (Porton Down veterans) and a similar group of 16,520 men who did not (non-Porton Down veterans).
Cancer morbidity in each group of veterans; rate ratios, with 95% confidence intervals, adjusted for age group and calendar period.
3457 cancers were reported in the Porton Down veterans compared with 3380 cancers in the non-Porton Down veterans. While overall cancer morbidity was the same in both groups (rate ratio 1.00, 95% confidence interval 0.95 to 1.05), Porton Down veterans had higher rates of ill defined malignant neoplasms (1.12, 1.02 to 1.22), in situ neoplasms (1.45, 1.06 to 2.00), and those of uncertain or unknown behaviour (1.32, 1.01 to 1.73).
Overall cancer morbidity in Porton Down veterans was no different from that in non-Porton Down veterans.
[show abstract][hide abstract] ABSTRACT: This study describes exposures to military veterans who participated between 1941 and 1989 in British research at Porton Down on the effects of exposure to chemical warfare agents and to defences against those agents. The study is part of a programme of epidemiological research initiated in response to service veterans' concerns about possible long-term health effects of their participation.
All entries in 97 books held in the Porton Down historical experimental archive covering the years 1939-1989 were reviewed. For tests between April 1941 and December 1989, data were abstracted on chemicals used, with additional detail abstracted for tests involving vesicants and nerve agents. For tests recorded during 1939-1941, similar data were abstracted for a representative sample of tests.
Historical data were abstracted for 17 303 veterans included in the cohort study of 18,276 servicemen who took part in tests at Porton Down between 1941 and 1989. The median number of days per veteran on which tests were carried out was 2 days. The median difference between the last and first day of testing was 4 days. A large number of chemicals were tested over this period (n = 492). The type of chemical tested varied over time. Exposures were often modified by respirator use or use of protective clothing or protective equipment. It was possible to assign a quantitative measure of cumulative exposure to 73% of veterans exposed to the vesicant sulphur mustard--3491 (34%) of exposed veterans had cumulative exposures > or =10.63 mg and for 70% of veterans exposed to the nerve agent sarin--658 (29%) of exposed veterans had cumulative exposures > or =15.0 mg min m(-3). Ninety-three per cent of veterans exposed to sulphur mustard were classified to a semi-quantitative scale of dermal effect--3771 (37%) had a vesicle or necrosed area, and 69% of veterans exposed to sarin could be categorized by change in blood cholinesterase activity--1033 (31%) had a depression in cholinesterase activity of > or =30%.
The experimental archive at Porton Down has proved to be a rich source of data on tests conducted between 1941 and 1989. It has been possible to categorize most veterans according to date of test, chemical group, chemical, type of protection and, for certain chemicals, level of exposure and/or degree of acute toxicity. These categorizations have been used to assign veterans to exposure groups for epidemiological analysis.
Annals of Occupational Hygiene 02/2009; 53(1):83-97. · 2.16 Impact Factor
[show abstract][hide abstract] ABSTRACT: Burkitt lymphoma, a childhood tumor common in parts of sub-Saharan Africa, has been directly associated with Epstein-Barr virus (EBV) and indirectly with prevalence of malaria. We studied antibodies to both EBV and malaria in children diagnosed with this cancer in Uganda. We performed a case-control study of HIV-seronegative children (<or=15 years) admitted to hospital. Cases were diagnosed with Burkitt lymphoma and controls with non-malignant conditions or non-lymphatic cancers. Interviews were conducted and serological samples collected and, when possible, tested for both EBV and malaria. Adjusted odds ratios (ORs) for Burkitt lymphoma were estimated using unconditional logistic regression adjusting for sex, age, residential district, household income and tribe. The mean age of cases was 7 years and 61% were male. Compared to controls, cases were more likely to be reported having received more frequent treatment for malaria in the past year (OR = 2.0; p = 0.001) and less likely to be living in a home where insecticides were used (OR = 0.2; p < 0.0001). Odds ratios for Burkitt lymphoma in children increased with increasing antibody levels against EBV (p < 0.0001) and malaria (p = 0.05). Findings were similar for children residing in districts close to the capital city and in remote areas. Cases were 5 times more likely than controls to have raised levels of both EBV and malaria antibodies (OR = 5.0; p = 0.003). Our findings suggest that EBV and malaria may act synergistically in the pathogenesis of childhood Burkitt lymphoma. Malaria prevention measures may also prevent this childhood cancer.
International Journal of Cancer 03/2008; 122(6):1319-23. · 6.20 Impact Factor
[show abstract][hide abstract] ABSTRACT: Burkitt lymphoma, a childhood cancer common in parts of sub-Saharan Africa, has been associated with Epstein Barr Virus (EBV) and malaria, but its association with human immunodeficiency virus (HIV) is not clear.
We conducted a case-control study of Burkitt lymphoma among children (aged < or = 15 years) admitted to the pediatric oncology unit in Blantyre, Malawi between July 2005 and July 2006. Cases were 148 children diagnosed with Burkitt lymphoma and controls were 104 children admitted with non-malignant conditions or cancers other than hematological malignancies and Kaposi sarcoma. Interviews were conducted and serological samples tested for antibodies against HIV, EBV and malaria. Odds ratios for Burkitt lymphoma were estimated using unconditional logistic regression adjusting for sex, age, and residential district. Cases had a mean age of 7.1 years and 60% were male. Cases were more likely than controls to be HIV positive (Odds ratio (OR)) = 12.4, 95% Confidence Interval (CI) 1.3 to 116.2, p = 0.03). ORs for Burkitt lymphoma increased with increasing antibody titers against EBV (p = 0.001) and malaria (p = 0.01). Among HIV negative participants, cases were thirteen times more likely than controls to have raised levels of both EBV and malaria antibodies (OR = 13.2; 95% CI 3.8 to 46.6; p = 0.001). Reported use of mosquito nets was associated with a lower risk of Burkitt lymphoma (OR = 0.2, 95% CI, 0.03 to 0.9, p = 0.04).
Our findings support prior evidence that EBV and malaria act jointly in the pathogenesis of Burkitt lymphoma, suggesting that malaria prevention may decrease the risk of Burkitt lymphoma. HIV may also play a role in the etiology of this childhood tumor.
PLoS ONE 01/2008; 3(6):e2505. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: As part of an epidemiological study of cancer in Uganda, we investigated social, sexual and reproductive factors in relation to the risk of cancer of the uterine cervix. Patients with all cancer types or with benign tumours were recruited from hospitals in Kampala, Uganda, interviewed about various demographic and lifestyle factors and tested for antibodies against the human immunodeficiency virus-1 (HIV). The case-control study reported here involves 702 HIV-seronegative women, 343 of whom were diagnosed with cancer of the uterine cervix. Key findings were that the risk of cervical cancer increased linearly with the number of pregnancies [chi2(1)=44.7; P<0.0001]; a woman reporting having had 10 or more children had a roughly seven-fold increase in risk of the tumour as compared with women reporting fewer than four pregnancies (odds ratio=7.1; 95% confidence interval 3.8-13.2). The risk also varied inversely with age at first reported sexual intercourse [chi2(1)=8.4; P=0.004], perhaps reflecting an earlier age of infection with human papillomavirus, the main causal agent. These results are in line with those reported from studies in other countries.
European Journal of Cancer Prevention 12/2007; 16(6):555-8. · 2.97 Impact Factor
[show abstract][hide abstract] ABSTRACT: To report the experience of health workers who had played key roles in the early stages of implementing the prevention of mother-to-child HIV transmission services (PMTCT) in Uganda.
Interviews were conducted with 15 key informants including counsellors, obstetricians and PMTCT coordinators at the five PMTCT test sites in Uganda to investigate the benefits, challenges and sustainability of the PMTCT programme. Audio-taped interviews were held with each informant between January and June 2003. These were transcribed verbatim and manually analysed using the framework approach.
The perceived benefits reported by informants were improvement of general obstetric care, provision of antiretroviral prophylaxis for HIV-positive mothers, staff training and community awareness. The main challenges lay in the reluctance of women to be tested for HIV, incomplete follow-up of participants, non-disclosure of HIV status and difficulties with infant feeding for HIV-positive mothers. Key informants thought that the programme's sustainability depended on maintaining staff morale and numbers, on improving services and providing more resources, particularly antiretroviral therapy for the HIV-positive women and their families.
Uganda's experience in piloting the PMTCT programme reflected the many challenges faced by health workers. Potentially resource-sparing strategies such as the 'opt-out' approach to HIV testing required further evaluation.
Journal of Public Health 10/2007; 29(3):269-74. · 1.99 Impact Factor
[show abstract][hide abstract] ABSTRACT: As part of an epidemiological study of cancer in Uganda, we investigated the titre of antibodies against BK virus among 821 people with different cancer types and benign tumours. Among study participants, 790 were considered seropositive for anti-BK virus antibodies and all analyses were conducted on transformed data. The mean optical density (a measure of antibody titre) for all patients combined (including the 31 who were considered seronegative) was 1.03 (standard error 0.01), but was 5% higher in women than in men (P=0.05), and 8% higher among HIV seropositive than seronegative people (P=0.002). Otherwise, there were few consistent associations between anti-BK virus antibodies and any social and lifestyle factor investigated. Differences in the mean optical density for each cancer type were estimated using multivariate analysis of variance with adjustment for sex, age group and HIV serostatus, using all other patients as controls. The mean optical density was about 17% lower among those with oral cancer (optical density 0.86, standard error 0.06; P=0.01, based on 30 patients) and about 20% higher among those with prostate cancer (optical density 1.22, standard error 0.09; P=0.01, based on 11 cases) than among all other patients combined. The number of cases of each cancer was too small to exclude the possibility of these findings arising by chance. No other cancer site or type was significantly associated with low, or with high anti-BK virus antibody titres.
European Journal of Cancer Prevention 09/2006; 15(4):285-9. · 2.97 Impact Factor
[show abstract][hide abstract] ABSTRACT: There has been a Human Volunteer Programme at the British chemical weapons research facility at Porton Down since the First World War, in which some of the participants were exposed to chemical warfare agents.
To identify any striking specific morbidity patterns in members of the Porton Down Veterans Support Group (PDVSG).
A self-completed postal questionnaire was prepared including health immediately after the visits to Porton Down, subsequent diagnoses and hospital admissions, symptoms in, and after, the first 5 years after the visits, fatigue symptoms and current quality of life, measured using the SF-36.
Responses were received from 289 of 436 (66%). Results reported here relate to 269 male respondents of mean age 66.8 years. Sixty-six per cent reported their first visit to Porton Down in the 1950s. The most common diagnoses or hospital admissions reported were diseases of the circulatory system. In the first 5 years after their visits the most common symptoms were headache, irritability or outbursts of anger and feeling un-refreshed after sleep. In the later period, most common symptoms were fatigue, feeling un-refreshed after sleep and sleeping difficulties. Sixty-five per cent met the definition for a case of 'fatigue'. Current quality of life dimensions were consistently lower than age-specific estimates from general population samples.
Members of the PDVSG responding to this survey reported poorer quality of life than the general population. Despite there being no clear pattern of specific morbidities, we cannot rule out ill-health being potentially associated with past experience at Porton Down.
Occupational Medicine 09/2006; 56(5):329-37. · 1.45 Impact Factor
[show abstract][hide abstract] ABSTRACT: To study the effect of HIV infection on quality of life (QOL) during pregnancy and puerperium, QOL was measured in a cohort study at St. Francis Hospital Nsambya, Kampala, Uganda. Dartmouth COOP charts were administered to 132 HIV-positive and 399 HIV-negative women at 36 weeks of pregnancy and six weeks post-partum. Responses were coded from 0 = best health-status to 4 = worst health-status and scores of 3-4 defined as poor. Odds ratios (OR) (95% confidence intervals(CI)) for poor scores were calculated and independent predictors of poor QOL examined using logistic regression. In pregnancy, HIV-positive women were more likely to have poor scores in feelings: OR = 3.2(1.9-5.3), daily activities: OR = 2.8(1.4-5.5), pain: OR = 2.1(1.3-3.5), overall health: OR = 1.7(1.1-2.7) and QOL: OR = 7.2(3.6-14.7), all p= <or= 0.01. Differences in physical fitness, change in health, social activities and social support were not statistically significant (all p>0.2). HIV infection was independently associated with poor QOL: OR = 8.5(3.8-19). Findings in puerperium were similar to those in pregnancy except more HIV-positive women had poor scores in social activities: OR = 2.5(1.4-4.7) and change in health: OR = 5.4(2-14.5) and infant death also predicted poor QOL: OR = 6.7(2.4-18.5). The findings reflect HIV's adverse impact on maternal QOL and the need for interventions to alleviate this infection's social and emotional effects.
AIDS Care 08/2006; 18(6):614-20. · 1.60 Impact Factor
[show abstract][hide abstract] ABSTRACT: Antibody titres against Kaposi's sarcoma associated herpesvirus (KSHV or human herpesvirus 8 (HHV-8)) and Epstein-Barr virus (EBV) were examined in people who subsequently developed Kaposi's sarcoma and non-Hodgkin's lymphoma, within randomised controlled trials of antiretroviral therapy in adults infected with the human immunodeficiency virus-1 (HIV). For each case of Kaposi's sarcoma (n=189) and each case of non-Hodgkin's lymphoma (n=67), which developed after randomisation, one control was randomly selected from other trial participants, after matching for age, sex, ethnicity, mode of HIV transmission, type of treatment received and period of follow-up. Using sera taken an average of two and a half years before the diagnosis of cancer, titres of antibodies against KSHV latent (LANA) and lytic (K8.1) antigens and against EBV (VCA) antigens were investigated in relation to subsequent risks of cancer by calculating odds ratios (OR) using conditional logistic regression. Latent antibodies against KSHV were detectable among 38% (72 out of 189) of Kaposi's sarcoma cases and 12% (23 out of 189) of their controls (OR=4.4, 95% confidence intervals (CI) 2.3-8.3, P<0.001). The OR for Kaposi's sarcoma increased with increasing antilatent KSHV antibody titre (chi(2)(1) for trend=32.2, P<0.001). Lytic antibodies against KSHV were detectable among 33% (61 out of 187) of Kaposi's sarcoma cases and 19% (36 out of 187) of their controls (OR=2.0, 95% CI 1.2-3.4, P=0.003) and the OR for Kaposi's sarcoma increased with increasing antilytic KSHV antibody titre (chi(2)(1) for trend=6.2, P=0.02). Virtually, all cases and controls had anti-EBV antibodies detected and the OR for non-Hodgkin's lymphoma associated with a doubling of the anti-EBV antibody titre was estimated to increase by a multiplicative factor of 1.3 (95% CI 0.9-1.7, P=0.1). Kaposi's sarcoma was not associated with antibody levels against EBV (P=0.4) and non-Hodgkin's lymphoma was not associated with antibodies against KSHV (latent P=0.3; lytic P=0.5). Adjustment for CD4 count at the time of sample collection made no material difference to any of the results. In conclusion, among human immunodeficiency virus infected people, high levels of antibodies against KSHV latent and lytic antigens are strongly associated with subsequent risk of Kaposi's sarcoma but not non-Hodgkin's lymphoma. Antibody titre to EBV does not appear to be strongly associated with subsequent risk of Kaposi's sarcoma or non-Hodgkin's lymphoma in HIV infected people.
British Journal of Cancer 06/2006; 94(10):1504-9. · 5.08 Impact Factor
[show abstract][hide abstract] ABSTRACT: Data from Africa on infection with Helicobacter pylori (H. pylori) are sparse. Therefore, as part of an epidemiological study of cancer in Uganda, we investigated the prevalence and determinants of antibodies against H. pylori among 854 people with different cancer types and benign tumours. Patients were recruited from hospitals in Kampala, Uganda, interviewed about various demographic and lifestyle factors and tested for antibodies against H. pylori. In all patients combined, excluding those with stomach cancer (which has been associated with H. pylori infection), the prevalence of antibodies was 87% (723/833) overall, but declined with increasing age (p = 0.02) and was lower among people who were HIV seropositive compared to seronegative (p < 0.001). Otherwise, there were few consistent epidemiological associations. Among those with stomach cancer, 18/21 (86%) had anti-H. pylori antibodies (odds ratio 0.8, 95% confidence intervals 0.2-2.9, p = 0.7; estimated using all other patients as controls, with adjustment for age, sex and HIV serostatus). No other cancer site or type was significantly associated with anti-H. pylori antibodies. The prevalence of H. pylori reported here is broadly in accord with results from other developing countries, although the determinants of infection and its' role in the aetiology of gastric cancer in Uganda remain unclear.
[show abstract][hide abstract] ABSTRACT: Changing behaviour is an important method for preventing HIV infection. We examined why a community randomized trial of a behavioural intervention found no significant effect of this on HIV incidence in rural Uganda.
An individual-level analysis of a community randomized trial.
All sexually active, initially HIV-seronegative individuals with data on sexual behaviour were included (1558 men and 1836 women). Uptake of the intervention was measured using self-reported attendance at meetings, videos, dramas, and interactions with community educators in the past year. Sexual behaviour was assessed using self-reported condom use and the number of sexual partners in the past year.
Overall, 81% of individuals in the intervention communities and 9% in the comparison communities reported attending at least one of the intervention activities in the past year. Attendance was lower in women, in those aged 55 years or older, and in the widowed. There was a lower HIV incidence in those who reported attending at least one intervention activity compared with those who attended none, and in women this effect was statistically significant (in women, adjusted rate ratio 0.41, 95% CI 0.19-0.89, P = 0.024; in men, adjusted rate ratio 0.66, 95% CI 0.25-1.79, P = 0.42). Reported behaviour change did not differ markedly between those who did and did not report attending any intervention activities.
Although the intervention had no significant benefit in the communities as a whole, it resulted in a reduced risk of HIV acquisition in women who attended it. The methodological implications for future trials are discussed.
AIDS 11/2004; 18(15):2055-63. · 6.41 Impact Factor
[show abstract][hide abstract] ABSTRACT: In a case-control study in Uganda, we examined associations between different cancer sites or types in relation to antibodies against human papillomaviruses (HPV)-16, -18 and -45. For each cancer site or type, the control group comprised all other cancers excluding those known, or thought to be associated with HPV infection (cancers of the uterine cervix, penis and eye). Among controls the seroprevalence of antibodies was 11% (68/616) against HPV-16, 5% (29/605) against HPV-18 and 6% (35/605) against HPV-45. Antibodies against HPV-16 were significantly associated with only two cancers: uterine cervix [prevalence of antibodies 27% (51/191); odds ratio (OR) 2.0, 95% confidence interval (CI) 1.2-3.1, P=0.01] and penis [prevalence of antibodies 27% (4/15); OR 6.4, 95% CI 1.7-24.3, P=0.01]. For both cancers, the risk increased with increasing anti-HPV-16 antibody titre (Ptrend=0.01 for each). No cancer site or type was significantly associated with antibodies against HPV-18 and -45.
European Journal of Cancer Prevention 05/2004; 13(2):113-8. · 2.97 Impact Factor
[show abstract][hide abstract] ABSTRACT: Randomized intervention trials in which the community is the unit of randomization are increasingly being used to evaluate the impact of public health interventions. In the design of community randomized trials (CRT), the power of the study is likely to be affected by two issues: the matching or stratification of communities, and the number and size of the communities to be randomized.
Data from three East African community intervention trials, designed to evaluate the impact of interventions to reduce human immunodeficiency virus (HIV) incidence, are used to compare the efficiency of different trial designs.
Compared with an unmatched design, stratification reduced the between-community variation in the Mwanza trial (from 0.51 to 0.24) and in the Masaka trial (from 0.38 to 0.28). The reduction was smaller in the Rakai trial where the selected communities were more homogeneous (from 0.15 to 0.11). For all trials, individual matching of communities produced estimates of between-community variation similar to those from the stratified designs. The linear association between HIV prevalence and incidence was strong in the Mwanza trial (correlation coefficient R = 0.83) and the Masaka trial (R = 0.83), but weak in the Rakai trial (R = 0.28). Unmatched study designs that use smaller communities tend to increase between-community variation, but reduce the design effect and improve study power.
These empirical data suggest that selection of homogeneous communities, or stratification of communities prior to randomization, may improve the power of CRT.
International Journal of Epidemiology 11/2003; 32(5):755-62. · 6.98 Impact Factor
[show abstract][hide abstract] ABSTRACT: A case-control study from Uganda found that the risk of Kaposi's sarcoma increased with increasing titre of antibodies against Kaposi's sarcoma-associated herpesvirus (KSHV) latent nuclear antigens, independently of HIV infection. Clinically, widespread Kaposi's sarcoma was more frequent among patients with HIV infection than in those without, but was not related to anti-KSHV antibody titres.
British Journal of Cancer 09/2003; 89(3):502-4. · 5.08 Impact Factor