Marcel Tanner

Ifakara Health Institute, Dār es Salām, Dar es Salaam, Tanzania

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Publications (579)2716.68 Total impact

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    ABSTRACT: The malaria vaccine RTS,S induces antibodies against the Plasmodium falciparum circumsporozoite protein (CSP) and the concentration of Immunoglobulin G (IgG) against the repeat region of CSP following vaccination is associated with protection from P. falciparum malaria. So far, only the quantity of anti-CSP IgG has been measured and used to predict vaccination success, although quality (measured as avidity) of the antigen-antibody interaction shall be important since only a few sporozoites circulate for a short time after an infectious mosquito bite, likely requiring fast and strong binding. Quantity and avidity of anti-CSP IgG in African infants who received RTS,S/AS01E in a 0-1-2-month or a 0-1-7-month schedule in a phase 2 clinical trial were measured by enzyme-linked immunosorbent assay. Antibody avidity was defined as the proportion of IgG able to bind in the presence of a chaotropic agent (avidity index). The effect of CSP-specific IgG concentration and avidity on protective efficacy was modelled using Cox proportional hazards. After the third dose, quantity and avidity were similar between the two vaccination schedules. IgG avidity after the last vaccine injection was not associated with protection, whereas the change in avidity following second and third RTS,S/AS01E injection was associated with a 54% risk reduction of getting malaria (hazard ratio: 0.46; 95% confidence interval (CI): 0.22-0.99) in those participants with a change in avidity above the median. The change in anti-CSP IgG concentration following second and third injection was associated with a 77% risk reduction of getting malaria (hazard ratio: 0.23, 95% CI: 0.11-0.51). Change in IgG response between vaccine doses merits further evaluation as a surrogate marker for RTS,S efficacy. Identifier NCT00436007 .
    Malaria Journal 12/2015; 14(1). DOI:10.1186/s12936-015-0605-7 · 3.11 Impact Factor
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    ABSTRACT: Background: In sub-Saharan Africa, the prevalence of HIV among married and cohabiting couples is substantial. Information about the underlying social drivers of HIV transmission in couples is critical for the development of structural approaches to HIV prevention, but not readily available. We explored the association between social drivers, practices, and HIV status among stable couples in Ifakara, Tanzania. Design: Using a cross-sectional design, we analyzed data from a sample of 3,988 married or cohabiting individuals, aged 15 years and older from the MZIMA adult health community cohort study of 2013. Sociodemographic factors (sex, income, age, and education), gender norms (perceived acceptability for a wife to ask her partner to use a condom when she knows he is HIV positive), marriage characteristics (being in a monogamous or a polygamous marriage, being remarried), sexual behavior practices (lifetime number of sexual partners and concurrent sexual partners), health system factors (ever used voluntary HIV counseling and testing), and lifestyle patterns (alcohol use) were used to explore the odds of being HIV positive, with 95% confidence intervals. Results: Prevalence of HIV/AIDS was 6.7% (5.9% males and 7.1% females). Gender norms, that is, perception that a woman is not justified to ask her husband to use a condom even when she knows he has a disease (adjusted odds ratio AOR=1.51, 95% CI 1.06-2.17), marital characteristics, that is, being remarried (AOR=1.49, 95% CI 1.08-2.04), and sexual behavior characteristics, that is, lifetime number of sexual partners (2-4: AOR=1.47, 95% CI 1.02-2.11; 5+: AOR=1.61, 95% CI 1.05-2.47) were the main independent predictors of HIV prevalence. Conclusions: Among married or cohabiting individuals, the key social drivers/practices that appeared to make people more vulnerable for HIV are gender norms, marriage characteristics (being remarried), and sexual behavior practices (lifetime number of sexual partners). Married and cohabiting couples are an important target group for HIV prevention efforts in Tanzania. In addition to individual interventions, structural interventions are needed to address the gender norms, remarriage, and sexual practices that shape differential vulnerability to HIV in stable couples.
    Global Health Action 09/2015; 8. DOI:10.3402/gha.v8.28941 · 1.93 Impact Factor
  • PLoS Medicine 09/2015; 12(9):e1001881. DOI:10.1371/journal.pmed.1001881 · 14.43 Impact Factor
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    ABSTRACT: Background: Clinical trials of the RTS,S malaria vaccine have completed Phase III and the vaccine is on track for registration. Before making decisions about implementation, it is essential to prepare the ground for introducing the vaccine by assessing awareness and willingness to use malaria vaccines and to provide policy makers with evidence-based information on the best strategies to engage communities to manage the introduction of malaria vaccine in Tanzania. Methods: In November 2011, as part of a large cross-sectional study of all 23 regions of Tanzania (mainland Tanzania and Zanzibar) was conducted during Tanzanian Integrated Measles Campaign (IMC) survey. In this study, the variables of interests were awareness and willingness to use a malaria vaccine. The main outcome measure was willingness to use a malaria vaccine. Logistic regression was used to examine the influence of predictive factors. Results: A representative sample of 5502 (out of 6210) women, aged 18 years or older and with children under 11 months old, was selected to participate, using random sampling probability. Awareness of the forthcoming malaria vaccine, 11.8 % of participants in mainland Tanzania responded affirmatively, compared to 3.4 % in Zanzibar (p value <0.0001). 94.5 % of all respondents were willing to vaccinate their children against malaria, with a slight difference between mainland Tanzania (94.3 %) and Zanzibar (96.8 %) (p value = 0.0167). Conclusions: Although mothers had low awareness and high willingness to use malaria vaccine, still availability of malaria vaccine RTS,S will compliment other existing malaria interventions and it will be implemented through the Immunization, Vaccines and Biologicals (IVB) programme (formerly EPI). The information generated from this study can aid policy makers in planning and setting priorities for introducing and implementing the malaria vaccine.
    Malaria Journal 09/2015; 14(1):355. DOI:10.1186/s12936-015-0889-7 · 3.11 Impact Factor
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    ABSTRACT: This appendix provides two supplementary figures and ten supplementary tables.
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    ABSTRACT: Background The Global Burden of Disease Study 2013 (GBD 2013) aims to bring together all available epidemiological data using a coherent measurement framework, standardised estimation methods, and transparent data sources to enable comparisons of health loss over time and across causes, age–sex groups, and countries. The GBD can be used to generate summary measures such as disability-adjusted life-years (DALYs) and healthy life expectancy (HALE) that make possible comparative assessments of broad epidemiological patterns across countries and time. These summary measures can also be used to quantify the component of variation in epidemiology that is related to sociodemographic development. Methods We used the published GBD 2013 data for age-specific mortality, years of life lost due to premature mortality (YLLs), and years lived with disability (YLDs) to calculate DALYs and HALE for 1990, 1995, 2000, 2005, 2010, and 2013 for 188 countries. We calculated HALE using the Sullivan method; 95% uncertainty intervals (UIs) represent uncertainty in age-specific death rates and YLDs per person for each country, age, sex, and year. We estimated DALYs for 306 causes for each country as the sum of YLLs and YLDs; 95% UIs represent uncertainty in YLL and YLD rates. We quantified patterns of the epidemiological transition with a composite indicator of sociodemographic status, which we constructed from income per person, average years of schooling after age 15 years, and the total fertility rate and mean age of the population. We applied hierarchical regression to DALY rates by cause across countries to decompose variance related to the sociodemographic status variable, country, and time. Findings Worldwide, from 1990 to 2013, life expectancy at birth rose by 6·2 years (95% UI 5·6–6·6), from 65·3 years (65·0–65·6) in 1990 to 71·5 years (71·0–71·9) in 2013, HALE at birth rose by 5·4 years (4·9–5·8), from 56·9 years (54·5–59·1) to 62·3 years (59·7–64·8), total DALYs fell by 3·6% (0·3–7·4), and age-standardised DALY rates per 100 000 people fell by 26·7% (24·6–29·1). For communicable, maternal, neonatal, and nutritional disorders, global DALY numbers, crude rates, and age-standardised rates have all declined between 1990 and 2013, whereas for non–communicable diseases, global DALYs have been increasing, DALY rates have remained nearly constant, and age-standardised DALY rates declined during the same period. From 2005 to 2013, the number of DALYs increased for most specific non-communicable diseases, including cardiovascular diseases and neoplasms, in addition to dengue, food-borne trematodes, and leishmaniasis; DALYs decreased for nearly all other causes. By 2013, the five leading causes of DALYs were ischaemic heart disease, lower respiratory infections, cerebrovascular disease, low back and neck pain, and road injuries. Sociodemographic status explained more than 50% of the variance between countries and over time for diarrhoea, lower respiratory infections, and other common infectious diseases; maternal disorders; neonatal disorders; nutritional deficiencies; other communicable, maternal, neonatal, and nutritional diseases; musculoskeletal disorders; and other non-communicable diseases. However, sociodemographic status explained less than 10% of the variance in DALY rates for cardiovascular diseases; chronic respiratory diseases; cirrhosis; diabetes, urogenital, blood, and endocrine diseases; unintentional injuries; and self-harm and interpersonal violence. Predictably, increased sociodemographic status was associated with a shift in burden from YLLs to YLDs, driven by declines in YLLs and increases in YLDs from musculoskeletal disorders, neurological disorders, and mental and substance use disorders. In most country-specific estimates, the increase in life expectancy was greater than that in HALE. Leading causes of DALYs are highly variable across countries. Interpretation Global health is improving. Population growth and ageing have driven up numbers of DALYs, but crude rates have remained relatively constant, showing that progress in health does not mean fewer demands on health systems. The notion of an epidemiological transition—in which increasing sociodemographic status brings structured change in disease burden—is useful, but there is tremendous variation in burden of disease that is not associated with sociodemographic status. This further underscores the need for country-specific assessments of DALYs and HALE to appropriately inform health policy decisions and attendant actions.
    The Lancet 08/2015; DOI:10.1016/S0140-6736(15)61340-X · 45.22 Impact Factor
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    ABSTRACT: Although global efforts in the past decade have halved the number of deaths due to malaria, there are still an estimated 219 million cases of malaria a year, causing more than half a million deaths. In this forum article, we asked experts working in malaria research and control to discuss the ways in which malaria might eventually be eradicated. Their collective views highlight the challenges and opportunities, and explain how multi-factorial and integrated processes could eventually make malaria eradication a reality.
    BMC Medicine 07/2015; 13(1):167. DOI:10.1186/s12916-015-0384-6 · 7.25 Impact Factor
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    ABSTRACT: The RTS,S/AS01 malaria vaccine candidate recently completed Phase III trials in 11 African sites. Recommendations for its deployment will partly depend on predictions of public health impact in endemic countries. Previous predictions of these used only limited information on underlying vaccine properties and have not considered country-specific contextual data. Each Phase III trial cohort was simulated explicitly using an ensemble of individual-based stochastic models, and many hypothetical vaccine profiles. The true profile was estimated by Bayesian fitting of these models to the site- and time-specific incidence of clinical malaria in both trial arms over 18 months of follow-up. Health impacts of implementation via two vaccine schedules in 43 endemic sub-Saharan African countries, using country-specific prevalence, access to care, immunisation coverage and demography data, were predicted via weighted averaging over many simulations. The efficacy against infection of three doses of vaccine was initially approximately 65 % (when immunising 6-12 week old infants) and 80 % (children 5-17 months old), with a 1 year half-life (exponential decay). Either schedule will avert substantial disease, but predicted impact strongly depends on the decay rate of vaccine effects and average transmission intensity. For the first time Phase III site- and time-specific data were available to estimate both the underlying profile of RTS,S/AS01 and likely country-specific health impacts. Initial efficacy will probably be high, but decay rapidly. Adding RTS,S to existing control programs, assuming continuation of current levels of malaria exposure and of health system performance, will potentially avert 100-580 malaria deaths and 45,000 to 80,000 clinical episodes per 100,000 fully vaccinated children over an initial 10-year phase.
    BMC Medicine 07/2015; 13(1):170. DOI:10.1186/s12916-015-0408-2 · 7.25 Impact Factor
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    ABSTRACT: This appendix provides further methodological detail, supplemental figures, and more detailed results for incidence, prevalence, and years of life lived with disability. The appendix is organised in broad sections following the structure of the main paper.
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    ABSTRACT: Background Up-to-date evidence about levels and trends in disease and injury incidence, prevalence, and years lived with disability (YLDs) is an essential input into global, regional, and national health policies. In the Global Burden of Disease Study 2013 (GBD 2013), we estimated these quantities for acute and chronic diseases and injuries for 188 countries between 1990 and 2013. Methods Estimates were calculated for disease and injury incidence, prevalence, and YLDs using GBD 2010 methods with some important refinements. Results for incidence of acute disorders and prevalence of chronic disorders are new additions to the analysis. Key improvements include expansion to the cause and sequelae list, updated systematic reviews, use of detailed injury codes, improvements to the Bayesian meta-regression method (DisMod-MR), and use of severity splits for various causes. An index of data representativeness, showing data availability, was calculated for each cause and impairment during three periods globally and at the country level for 2013. In total, 35 620 distinct sources of data were used and documented to calculated estimates for 301 diseases and injuries and 2337 sequelae. The comorbidity simulation provides estimates for the number of sequelae, concurrently, by individuals by country, year, age, and sex. Disability weights were updated with the addition of new population-based survey data from four countries. Findings Disease and injury were highly prevalent; only a small fraction of individuals had no sequelae. Comorbidity rose substantially with age and in absolute terms from 1990 to 2013. Incidence of acute sequelae were predominantly infectious diseases and short-term injuries, with over 2 billion cases of upper respiratory infections and diarrhoeal disease episodes in 2013, with the notable exception of tooth pain due to permanent caries with more than 200 million incident cases in 2013. Conversely, leading chronic sequelae were largely attributable to non-communicable diseases, with prevalence estimates for asymptomatic permanent caries and tension-type headache of 2·4 billion and 1·6 billion, respectively. The distribution of the number of sequelae in populations varied widely across regions, with an expected relation between age and disease prevalence. YLDs for both sexes increased from 537·6 million in 1990 to 764·8 million in 2013 due to population growth and ageing, whereas the age-standardised rate decreased little from 114·87 per 1000 people to 110·31 per 1000 people between 1990 and 2013. Leading causes of YLDs included low back pain and major depressive disorder among the top ten causes of YLDs in every country. YLD rates per person, by major cause groups, indicated the main drivers of increases were due to musculoskeletal, mental, and substance use disorders, neurological disorders, and chronic respiratory diseases; however HIV/AIDS was a notable driver of increasing YLDs in sub-Saharan Africa. Also, the proportion of disability-adjusted life years due to YLDs increased globally from 21·1% in 1990 to 31·2% in 2013. Interpretation Ageing of the world's population is leading to a substantial increase in the numbers of individuals with sequelae of diseases and injuries. Rates of YLDs are declining much more slowly than mortality rates. The non-fatal dimensions of disease and injury will require more and more attention from health systems. The transition to non-fatal outcomes as the dominant source of burden of disease is occurring rapidly outside of sub-Saharan Africa. Our results can guide future health initiatives through examination of epidemiological trends and a better understanding of variation across countries.
    The Lancet 06/2015; 386(9995):743–800. DOI:10.1016/S0140-6736(15)60692-4 · 45.22 Impact Factor
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    ABSTRACT: Figure appendix: Change in YLD rate from 1990 to 2013 for 188 countries and 21 regions (changes have been decomposed into 31 major cause groups and countries are ordered by the YLD rate in 1990).
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    ABSTRACT: Scale-up of malaria preventive and control interventions over the last decade resulted in substantial declines in mortality and morbidity from the disease in sub-Saharan Africa and many other parts of the world. Sustaining these gains will depend on the health system performance. Treatment provides individual benefits by curing infection and preventing progression to severe disease as well as community-level benefits by reducing the infectious reservoir and averting emergence and spread of drug resistance. However many patients with malaria do not access care, providers do not comply with treatment guidelines, and hence, patients do not necessarily receive the correct regimen. Even when the correct regimen is administered some patients will not adhere and others will be treated with counterfeit or substandard medication leading to treatment failures and spread of drug resistance. We apply systems effectiveness concepts that explicitly consider implications of health system factors such as treatment seeking, provider compliance, adherence, and quality of medication to estimate treatment outcomes for malaria case management. We compile data for these indicators to derive estimates of effective coverage for 43 high-burden Sub-Saharan African countries. Parameters are populated from the Demographic and Health Surveys and other published sources. We assess the relative importance of these factors on the level of effective coverage and consider variation in these health systems indicators across countries. Our findings suggest that effective coverage for malaria case management ranges from 8% to 72% in the region. Different factors account for health system inefficiencies in different countries. Significant losses in effectiveness of treatment are estimated in all countries. The patterns of inter-country variation suggest that these are system failures that are amenable to change. Identifying the reasons for the poor health system performance and intervening to tackle them become key priority areas for malaria control and elimination policies in the region.
    PLoS ONE 05/2015; 10(5):e0127818. DOI:10.1371/journal.pone.0127818 · 3.23 Impact Factor
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    ABSTRACT: Access to skilled obstetric delivery and emergency care is deemed crucial for reducing maternal mortality. We assessed pregnancy-related mortality by distance to health facilities and by cause of death in a disadvantaged rural area of southern Tanzania. We did a secondary analysis of cross-sectional georeferenced census data collected from June to October, 2007, in five rural districts of southern Tanzania. Heads of georeferenced households were asked about household deaths in the period June 1, 2004, to May 31, 2007, and women aged 13-49 years were interviewed about birth history in the same time period. Causes of death in women of reproductive age were ascertained by verbal autopsy. We also asked for sociodemographic information. Multilevel logistic regression was used to analyse the effects of distance to health facilities providing delivery care on pregnancy-related mortality (direct and indirect maternal and coincidental deaths). The study included 818 583 people living in 225 980 households. Pregnancy-related mortality was high at 712 deaths per 100 000 livebirths, with haemorrhage being the leading cause of death. Deaths due to direct causes of maternal mortality were strongly related to distance, with mortality increasing from 111 per 100 000 livebirths among women who lived within 5 km to 422 deaths per 100 000 livebirths among those who lived more than 35 km from a hospital (adjusted odds ratio 3·68; 95% CI 1·37-9·88). Neither pregnancy-related nor indirect maternal mortality was associated with distance to hospital. Among women who lived within 5 km of a hospital, pregnancy-related mortality was 664 deaths per 100 000 livebirths even though 72% gave birth in hospital and 8% had delivery by caesarean section. Large distances to hospital contribute to high levels of direct obstetric mortality. High pregnancy-related mortality in those living near to a hospital suggests deficiencies in quality of care. Bill & Melinda Gates Foundation. Copyright © 2015 Hanson et al. Open access article published under the terms of CC BY-NC-ND. Published by Elsevier Ltd.. All rights reserved.
    The Lancet Global Health 05/2015; 3(7). DOI:10.1016/S2214-109X(15)00048-0 · 10.04 Impact Factor
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    ABSTRACT: Current vital statistics from governmental institutions in Côte d'Ivoire are incomplete. This problem is particularly notable for remote rural areas that have limited access to the health system. To record all deaths from 2009 to 2011 and to identify the leading causes of death in the Taabo health and demographic surveillance system (HDSS) in south-central Côte d'Ivoire. Deaths recorded in the first 3 years of operation of the Taabo HDSS were investigated by verbal autopsy (VA), using the InterVA-4 model. InterVA-4 is based on the World Health Organization 2012 VA tool in terms of input indicators and categories of causes of death. Overall, 948 deaths were recorded, of which 236 (24.9%) had incomplete VA data. Among the 712 deaths analyzed, communicable diseases represented the leading causes (58.9%), with most deaths attributed to malaria (n=129), acute respiratory tract infections (n=110), HIV/AIDS (n=80), and pulmonary tuberculosis (n=46). Non-communicable diseases accounted for 18.9% of the deaths and included mainly acute abdomen (n=38), unspecified cardiac diseases (n=15), and digestive neoplasms (n=13). Maternal and neonatal conditions accounted for 8.3% of deaths, primarily pneumonia (n=19) and birth asphyxia (n=16) in newborns. Among the 3.8% of deaths linked to trauma and injury, the main causes were assault (n=6), accidental drowning (n=4), contact with venomous plants/animals (n=4), and traffic-related accidents (n=4). No clear causes were determined in 10.0% of the analyzed deaths. Communicable diseases remain the predominant cause of death in rural Côte d'Ivoire. Based on these findings, measures are now being implemented in the Taabo HDSS. It will be interesting to monitor patterns of mortality and causes of death in the face of rapid demographic and epidemiological transitions in this part of West Africa.
    Global Health Action 05/2015; 8:27271. DOI:10.3402/gha.v8.27271 · 1.93 Impact Factor
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    ABSTRACT: Summary Background The effi cacy and safety of the RTS,S/AS01 candidate malaria vaccine during 18 months of follow-up have been published previously. Herein, we report the fi nal results from the same trial, including the effi cacy of a booster dose. Methods From March 27, 2009, until Jan 31, 2011, children (age 5–17 months) and young infants (age 6–12 weeks) were enrolled at 11 centres in seven countries in sub-Saharan Africa. Participants were randomly assigned (1:1:1) at fi rst vaccination by block randomisation with minimisation by centre to receive three doses of RTS,S/AS01 at months 0, 1, and 2 and a booster dose at month 20 (R3R group); three doses of RTS,S/AS01 and a dose of comparator vaccine at month 20 (R3C group); or a comparator vaccine at months 0, 1, 2, and 20 (C3C [control group]). Participants were followed up until Jan 31, 2014. Cases of clinical and severe malaria were captured through passive case detection. Serious adverse events (SAEs) were recorded. Analyses were by modifi ed intention to treat and per protocol. The coprimary endpoints were the occurrence of malaria over 12 months after dose 3 in each age category. In this fi nal analysis, we present data for the effi cacy of the booster on the occurrence of malaria. Vaccine effi cacy (VE) against clinical malaria was analysed by negative binomial regression and against severe malaria by relative risk reduction. This trial is registered with, number NCT00866619. Findings 8922 children and 6537 young infants were included in the modifi ed intention-to-treat analyses. Children were followed up for a median of 48 months (IQR 39–50) and young infants for 38 months (34–41) after dose 1. From month 0 until study end, compared with 9585 episodes of clinical malaria that met the primary case defi nition in children in the C3C group, 6616 episodes occurred in the R3R group (VE 36·3%, 95% CI 31·8–40·5) and 7396 occurred in the R3C group (28·3%, 23·3–32·9); compared with 171 children who experienced at least one episode of severe malaria in the C3C group, 116 children experienced at least one episode of severe malaria in the R3R group (32·2%, 13·7 to 46·9) and 169 in the R3C group (1·1%, –23·0 to 20·5). In young infants, compared with 6170 episodes of clinical malaria that met the primary case defi nition in the C3C group, 4993 episodes occurred in the R3R group (VE 25·9%, 95% CI 19·9–31·5) and 5444 occurred in the R3C group (18·3%, 11·7–24·4); and compared with 116 infants who experienced at least one episode of severe malaria in the C3C group, 96 infants experienced at least one episode of severe malaria in the R3R group (17·3%, 95% CI –9·4 to 37·5) and 104 in the R3C group (10·3%, –17·9 to 31·8). In children, 1774 cases of clinical malaria were averted per 1000 children (95% CI 1387–2186) in the R3R group and 1363 per 1000 children (995–1797) in the R3C group. The numbers of cases averted per 1000 young infants were 983 (95% CI 592–1337) in the R3R group and 558 (158–926) in the R3C group. The frequency of SAEs overall was balanced between groups. However, meningitis was reported as a SAE in 22 children: 11 in the R3R group, ten in the R3C group, and one in the C3C group. The incidence of generalised convulsive seizures within 7 days of RTS,S/AS01 booster was 2·2 per 1000 doses in young infants and 2·5 per 1000 doses in children. Interpretation RTS,S/AS01 prevented a substantial number of cases of clinical malaria over a 3–4 year period in young infants and children when administered with or without a booster dose. Effi cacy was enhanced by the administration of a booster dose in both age categories. Thus, the vaccine has the potential to make a substantial contribution to malaria control when used in combination with other eff ective control measures, especially in areas of high transmission.
    The Lancet 04/2015; 385:1581. · 45.22 Impact Factor
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    ABSTRACT: Objectives: To report on trends of tuberculosis ascertainment among HIV patients in a rural HIV cohort in Tanzania, and assessing the impact of a bundle of services implemented in December 2012, consisting of three components: (i) integration of HIV and tuberculosis services; (ii) GeneXpert for tuberculosis diagnosis; and (iii) electronic data collection. Design: Retrospective cohort study of patients enrolled in the Kilombero Ulanga Antiretroviral Cohort (KIULARCO), Tanzania.). Methods: HIV patients without prior history of tuberculosis enrolled in the KIULARCO cohort between 2005 and 2013 were included.Cox proportional hazard models were used to estimate rates and predictors of tuberculosis ascertainment. Results: Of 7114 HIV positive patients enrolled, 5123 (72%) had no history of tuberculosis. Of these, 66% were female, median age was 38 years, median baseline CD4+ cell count was 243 cells/µl, and 43% had WHO clinical stage 3 or 4. During follow-up, 421 incident tuberculosis cases were notified with an estimated incidence of 3.6 per 100 person-years (p-y) [95% confidence interval (CI) 3.26-3.97]. The incidence rate varied over time and increased significantly from 2.96 to 43.98 cases per 100 p-y after the introduction of the bundle of services in December 2012. Four independent predictors of tuberculosis ascertainment were identified:poor clinical condition at baseline (Hazard Ratio (HR) 3.89, 95% CI 2.87-5.28), WHO clinical stage 3 or 4 (HR 2.48, 95% CI 1.88-3.26), being antiretroviralnaïve (HR 2.97, 95% CI 2.25-3.94), and registration in 2013 (HR 6.07, 95% CI 4.39-8.38). Conclusion: The integration of tuberculosis and HIV services together with comprehensive electronic data collection and use of GeneXpert increased dramatically the ascertainment of tuberculosis in this rural African HIV cohort.
    PLoS ONE 04/2015; : Haraka F, Glass TR, Sikalengo G, Gamell A, Ntamatungiro A, Hatz C, et al. (2015) A Bundle of Services Increased Ascertainment of Tuberculosis among HIV-Infected Individuals Enrolled in a HIV Cohort in Rural Sub-Saharan Africa. PLoS ONE 10(4): e0123275. doi:10.1371/journal.pone.0123275(4). DOI:10.1371/journal.pone.0123275 · 3.23 Impact Factor
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    ABSTRACT: Background: The Chronic Diseases Clinic Ifakara (CDCI) has been providing HIV care and treatment in Kilombero and Ulanga districts in Tanzania since 2005. Over time, several drug-refilling stations were created through the Tanzanian National AIDS Control Programme (NACP) to provide antiretroviral therapy (ART). Without any specific performance and outcome evaluation, these refilling stations were upgraded to comprehensive HIV care and treatment centres (CTCs). The objectives of this study were to evaluate the supply chain of the CTCs, key aspects of patient management and the coping strategies of theCTC staff andART patients during stock-outs of drugs and test kits. Methods: This explorative and cross-sectional study was undertaken in September 2011 and involved CDCI and all 11 peripheral CTCs in Kilombero and Ulanga districts in Tanzania. Data were collected through structured interviews with staff in charge of 12 sites and patients onART during un-announced visits. Results: All sites reported shortage of rapid tests to diagnose HIV. Seven (59%) CTCs experienced stock-outs of co-trimoxazole drugs. The CDCI and all but one peripheral CTC reported stock-outs of ARV medication. CD4 + T cell count service and second line drugs were available at the CDCI and in two CTCs only. To cope with the stock-out situation CTCs staff had to stop testing for HIV, substitute the treatment regimen depending on drug availability or close the CTC temporarily. Patients coped by skipping ARVs and co-trimoxazole medications. Conclusion: Access to ART in Kilombero and Ulanga districts has some critical imbalances in the supply chain and management for HIV/AIDS care and treatment. Potential strategies to overcome the barriers are discussed in relation to routine health management information system, investments into mobile-health and human resource capacity strengthening.
    Tanzania journal of health research 04/2015; 17(2). DOI:10.4314/thrb.v17i2
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    ABSTRACT: Plasmodium and soil transmitted helminth infections (STH) are a major public health problem, particularly among children. There are conflicting findings on potential association between these two parasites. This study investigated the Plasmodium and helminth co-infections among children aged 2 months to 9 years living in Bagamoyo district, coastal region of Tanzania. A community-based cross-sectional survey was conducted among 1033 children. Stool, urine and blood samples were examined using a broad set of quality controlled diagnostic methods for common STH (Ascaris lumbricoides, hookworm, Strongyloides stercoralis, Enterobius vermicularis, Trichuris trichura), schistosoma species and Wuchereria bancrofti. Blood slides and malaria rapid diagnostic tests (mRDTs) were utilized for Plasmodium diagnosis. Out of 992 children analyzed, the prevalence of Plasmodium infection was 13% (130/992), helminth 28.5% (283/992); 5% (50/992) had co-infection with Plasmodium and helminth. The prevalence rate of Plasmodium, specific STH and co-infections increased significantly with age (p < 0.001), with older children mostly affected except for S. stercoralis monoinfection and co-infections. Spatial variations of co-infection prevalence were observed between and within villages. There was a trend for STH infections to be associated with Plasmodium infection [OR adjusted for age group 1.4, 95% CI (1.0-2.1)], which was more marked for S. stercoralis (OR = 2.2, 95% CI (1.1-4.3). Age and not schooling were risk factors for Plasmodium and STH co-infection. The findings suggest that STH and Plasmodium infections tend to occur in the same children, with increasing prevalence of co-infection with age. This calls for an integrated approach such as using mass chemotherapy with dual effect (e.g., ivermectin) coupled with improved housing, sanitation and hygiene for the control of both parasitic infections.
    PLoS Neglected Tropical Diseases 04/2015; 9(4):e0003660. DOI:10.1371/journal.pntd.0003660 · 4.45 Impact Factor

Publication Stats

18k Citations
2,716.68 Total Impact Points


  • 2009–2015
    • Ifakara Health Institute
      Dār es Salām, Dar es Salaam, Tanzania
    • Institut de Formation et de Recherche Démographiques
      Jaúnde, Centre Region, Cameroon
  • 1982–2015
    • Swiss Tropical and Public Health Institute
      • Department of Epidemiology and Public Health
      Bâle, Basel-City, Switzerland
  • 2014
    • Umeå University
      Umeå, Västerbotten, Sweden
  • 1998–2014
    • Universität Basel
      • Swiss Tropical and Public Health Institute (Swiss TPH)
      Bâle, Basel-City, Switzerland
    • The University of Edinburgh
      • Institute of Cell Biology
      Edinburgh, Scotland, United Kingdom
  • 2011–2013
    • University of Queensland 
      • School of Population Health
      Brisbane, Queensland, Australia
    • Eawag: Das Wasserforschungs-Institut des ETH-Bereichs
      Duebendorf, Zurich, Switzerland
    • University of Tuebingen
      • Department of Tropical Medicine
      Tübingen, Baden-Württemberg, Germany
  • 2010–2013
    • London School of Hygiene and Tropical Medicine
      • Faculty of Infectious and Tropical Diseases
      Londinium, England, United Kingdom
  • 2007–2011
    • Centre Suisse De Recherches Scientifiques En Côte D'Ivoire
      Abijan, Lagunes, Ivory Coast
    • University of Nebraska Medical Center
      • College of Pharmacy
      Omaha, Nebraska, United States
  • 2008
    • National Institute of Parasitic Diseases
      Shanghai, Shanghai Shi, China
  • 2006
    • University of Abobo-Adjamé
      Abijan, Lagunes, Ivory Coast
    • Jiangsu Institute of Parasitic Diseases
      Wu-hsi, Jiangsu Sheng, China
  • 2001–2004
    • Princeton University
      • Office of Population Research
      Princeton, New Jersey, United States
    • University of Barcelona
      Barcino, Catalonia, Spain
  • 2002
    • Chinese Center For Disease Control And Prevention
      Peping, Beijing, China
    • University of Zurich
      Zürich, Zurich, Switzerland
  • 1996–2001
    • Hospital Clínic de Barcelona
      • Servicio de Microbiología
      Barcino, Catalonia, Spain
    • University of Oxford
      Oxford, England, United Kingdom
  • 1999
    • Doctors Without Borders
      Lutetia Parisorum, Île-de-France, France
  • 1997
    • Johns Hopkins University
      • Department of International Health
      Baltimore, Maryland, United States
  • 1986–1990
    • University of Geneva
      Genève, Geneva, Switzerland