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L'expérience "Talents émergents en santé mondiale": une forme de renforcement intensif des capacités des jeunes chercheurs du Sud
No full textResearchers from developing countries, French-speaking nations in particular, are underrepresented in the international biomedical and health literature. Various initiatives seek to address this problem. This article presents the experience of the Emerging Voices for Global Health (EV4GH) program. This initiative provided 52 young researchers from developing countries with intensive skills and content training, with an assortment of complementary components: training in scientific writing and presenting skills, immersion in global health and health systems research, an innovative presentation of their work at the 52nd colloquium of the Institute of Tropical Medicine in Antwerp, and an active role in the first Global Symposium on Health Systems Research, supervised by a team of experienced researchers/coaches who supported them in the publication of a scientific essay. This approach targeting researchers in developing countries and combining the development of skills and knowledge through the publication process, merits reproduction and encouragement. Young researchers from developing countries should not miss out on the second version of this program in October 2012 in Beijing, China
Peri-parturient rise of Cryptosporidium oocysts in cows: new insights provided by duplex quantitative real-time PCR
No full textIn order to clarify if a peri-parturient rise of Cryptosporidium parvum oocysts occurs in cows, faecal samples from 42 cows on two farms were collected. These samples were taken during the pre-parturient, the peri-parturient and the post-parturient periods. Two methods were used to detect the oocysts, a nested-PCR coupled with sequencing and a duplex real-time PCR (qPCR) that quantified Cryptosporidium spp. DNA concentration. The qPCR results were adjusted using a hierarchical Bayesian model taking into account within and between run variation. Generalised Estimating Equation models (GEE) were used to determine if peri-parturient cows were at greater risk of being infected than pre- or post-parturient cows. Fourteen dairy cows exhibited a peri-parturient and post-parturient rise in the excretion of Cryptosporidium spp. oocysts, other than the zoonotic C. parvum. The cows in the suckler beef farm were the only ones infected with the zoonotic species C. parvum at calving. Due to the low concentration of oocysts excreted mainly from species other than C. parvum, it would appear unlikely that cows act as a source of infection for their calves or contribute significantly to environmental contamination
Treatment outcomes among HIV-1 and HIV-2 infected children initiating antiretroviral therapy in a concentrated low prevalence setting in West Africa
No full textBACKGROUND: There is little data on responses to combination antiretroviral therapy (cART) among HIV-infected children in the West African region. We describe treatment outcomes among HIV-1 and HIV-2 infected children initiating cART in a research clinic in The Gambia, West Africa. METHODS: All treatment naive HIV-infected children who initiated cART according to the WHO ART guidelines for children between October 2004 and December 2009 were included in the analysis. Kaplan-Meir estimates and sign-rank test were used to investigate the responses to treatment. RESULTS: 65 HIV-1 and five HIV-2 infected children aged /=5 years at ART initiation were 470 cells/mm3 ((270 - 650; P = 0.0005), 230 cells/mm3 (30 - 610; P = 0.0196) and 615 cells/mm3 (250 - 1060; P = 0.0180) respectively. The proportions of children achieving undetectable HIV-1 viral load at 6-, 12-, 24- and 36 months of treatment were 24/38 (63.2%), 20/36 (55.6%), 8/22 (36.4%) and 7/12 (58.3%) respectively. The probability of survival among HIV-1 infected children after 12 months on ART was 89.9% (95% CI 78.8 - 95.3). CD4 T cell recovery was sub-optimal in all the HIV-2 infected children and none achieved virologic suppression. Two of the HIV-2 infected children died within 6 months of starting treatment while the remaining three were lost to follow-up. Conclusions: The beneficial effects of cART among HIV-1 infected children in our setting are sustained in the first 24 months of treatment with a significant improvement in survival experience up to 36 months; however the outcome was poor in the few HIV-2 infected children initiated on cART
Health systems frameworks in their political context: framing divergent agendas
No full textBACKGROUND: Despite the mounting attention for health systems and health systems theories, there is a persisting lack of consensus on their conceptualisation and strengthening. This paper contributes to structuring the debate, presenting landmarks in the development of health systems thinking against the backdrop of the policy context and its dominant actors. We argue that frameworks on health systems are products of their time, emerging from specific discourses. They are purposive, not neutrally descriptive, and are shaped by the agendas of their authors. DISCUSSION: The evolution of thinking over time does not reflect a progressive accumulation of insights. Instead, theories and frameworks seem to develop in reaction to one another, partly in line with prevailing paradigms and partly as a response to the very different needs of their developers. The reform perspective considering health systems as projects to be engineered is fundamentally different from the organic view that considers a health system as a mirror of society. The co-existence of health systems and disease-focused approaches indicates that different frameworks are complementary but not synthetic.The contestation of theories and methods for health systems relates almost exclusively to low income countries. At the global level, health system strengthening is largely narrowed down to its instrumental dimension, whereby well-targeted and specific interventions are supposed to strengthen health services and systems or, more selectively, specific core functions essential to programmes. This is in contrast to a broader conceptualization of health systems as social institutions. SUMMARY: Health systems theories and frameworks frame health, health systems and policies in particular political and public health paradigms. While there is a clear trend to try to understand the complexity of and dynamic relationships between elements of health systems, there is also a demand to provide frameworks that distinguish between health system interventions, and that allow mapping with a view of analysing their returns. The choice for a particular health system model to guide discussions and work should fit the purpose. The understanding of the underlying rationale of a chosen model facilitates an open dialogue about purpose and strategy
Identification of different trypanosome species in the mid-guts of tsetse flies of the Malanga (Kimpese) sleeping sickness focus of the Democratic Republic of Congo
No full textApplication of molecular techniques in the study of natural infection of Leishmania infantum vectors and utility of sandfly blood meal digestion for epidemiological surveys of leishmaniasis
No full textEpidemiological studies on the distribution of leishmaniasis caused by Leishmania infantum Nicolle, 1908 (Kinetoplastida: Trypanosomatidae) have been based principally on serological surveys of the canine reservoir. This methodology is useful due to the facility of sampling, the rapidity in obtaining results, its consistency and because it allows the detection of heterogeneous foci of canine leishmaniasis (CanL) even in small areas. Other investigations have analysed Leishmania parasitism in sandflies (Diptera: Psychodidae: Phlebotominae) by using classical dissection techniques. These techniques allow the vector species to be incriminated in different foci, although they suffer from being very time consuming. Lately, studies in this field are increasingly using molecular techniques, which are faster and easier to perform. In the present work, we applied a nested-PCR in a study of natural infection of sandflies by Leishmania in three isolated farms where serological data on canine leishmaniasis of local dogs were also obtained. The analysis allowed the detection of 38.7% of females with positive nested-PCR (78%, 18% and 0%, respectively, in the different isolated farms). The positive Leishmania DNA samples were genotyped and identified as L. infantum. The results of this work provide new data for the vectorial capacity of Phlebotomus ariasi in a Pyrenean area, which can be considered at risk of becoming a new focus of CanL. The females with positive nested-PCR displayed blood in the midgut at different degrees of digestion, and/or were gravid. According to the multivariate logistic regression analysis, the risk of nested-PCR-positivity increased significantly with the degree of blood digestion (OR = 1.3; P value = 0.025). The Phlebotomus species and the presence of eggs were not statistically associated with nested-PCR positivity (P value of >0.05). The correlation of positive nested-PCR results with the presence of seropositive dogs in the farm confirms the utility of this technique in the study of the distribution and intensity of leishmaniasis foci. Also, the importance of sandfly blood-meal digestion for epidemiological surveys of leishmaniasis foci has been demonstrated
Bladder morbidity and hepatic fibrosis in mixed Schistosoma haematobium and S. mansoni infections: a population-wide study in northern Senegal
No full textBACKGROUND: The global distribution map of schistosomiasis shows a large overlap of Schistosoma haematobium- and S. mansoni-endemic areas in Africa. Yet, little is known about the consequences of mixed Schistosoma infections for the human host. A recent study in two neighboring co-endemic communities in Senegal indicated that infection intensities of both species were higher in mixed than in single infections. Here, we investigated the relationship between mixed Schistosoma infections and morbidity in the same population. So far, this has only been studied in children. METHODS: Schistosoma infection was assessed by microscopy. Schistosoma-specific morbidity was assessed by ultrasound according to WHO guidelines. Multivariable logistic regression models were used to identify independent risk factors for morbidity. PRINCIPAL FINDINGS: Complete parasitological and morbidity data were obtained from 403 individuals. Schistosoma haematobium-specific bladder morbidity was observed in 83% and S. mansoni-specific hepatic fibrosis in 27% of the participants. Bladder morbidity was positively associated with S. haematobium infection intensity (OR = 1.9 (95% CI 1.3-2.9) for a 10-fold increase in intensity). Moreover, people with mixed infections tended to have less bladder morbidity than those with single S. haematobium infections (OR = 0.3 (95% CI 0.1-1.1)). This effect appeared to be related to ectopic S. mansoni egg elimination in urine. Hepatic fibrosis on the other hand was not related to S. mansoni infection intensity (OR = 0.9 (95% CI 0.6-1.3)), nor to mixed infections (OR = 1.0 (95% CI 0.7-1.7)). CONCLUSIONS/SIGNIFICANCE: This is the first population-wide study on the relationship between mixed Schistosoma infections and morbidity. Mixed infections did not increase the risk of S. mansoni-associated morbidity. They even tended to reduce the risk of S. haematobium-associated morbidity, suggesting a protective effect of S. mansoni infection on bladder morbidity. These unexpected results may have important consequences for schistosomiasis control in co-endemic areas and warrant further investigation
Performance of the PointCare NOW system for CD4 counting in HIV patients based on five independent evaluations
No full textINTRODUCTION: Point-of-care (POC) CD4 testing can improve access to treatment by enabling decentralization and reducing patient loss-to-follow-up. As new POC CD4 technologies become available, their performance should be assessed before widespread deployment. This study reports the findings of five independent evaluations of the PointCare NOW CD4 system. MATERIALS/METHODS: Evaluations were conducted in Southern Africa (Mozambique, South Africa) and North America (Canada, USA). 492 blood samples (55 from HIV-negative blood donors and 437 from HIV-infected patients, including 20 children aged between 12 and 59 months) were tested with both the PointCare NOW and reference flow cytometry instruments. Assessment of bias, precision and levels of clinical misclassification for absolute and percent CD4 count was conducted. RESULTS: PointCare NOW significantly overestimated CD4 absolute counts with a mean relative bias of +35.0%. Bias was greater in samples with CD4 counts below 350 cells/microl stratum (15.1%). Bias in CD4% had a similar trend with an overall relative mean bias of +25.6% and a larger bias for low CD4 stratum (+40.2%) than the higher CD4 stratum (+5.8%). Relative bias for CD4% in children was -6.8%. In terms of repeatability, PointCare NOW had a coefficient of variation of 11%. Using a threshold of 350 cells/microl, only 47% of patients who qualified for antiretroviral therapy with reference CD4 testing, would have been eligible for treatment with PointCare NOW test results. This was 39% using a 200 cells/microl threshold. Agreement with infant samples was higher, with 90% qualifying at a 25% eligibility threshold. CONCLUSION: The performance of the PointCare NOW instrument for absolute and percent CD4 enumeration was inadequate for HIV clinical management in adults. In children, the small sample size was not large enough to draw a conclusion. This study also highlights the importance of independent evaluation of new diagnostic technology platforms before deployment
Decline in HIV prevalence among young men in the general population of Cotonou, Benin, 1998-2008
No full textOBJECTIVE: To assess changes in the prevalence of HIV and other sexually transmitted infections, as well as in different proximal and distal factors related to HIV infection, in the general population of Cotonou between 1998 and 2008, while an intensive preventive intervention targeting the sex work milieu was ongoing. METHODS: A two-stage cluster sampling procedure was used to select the participants in each study. Subjects aged 15-49 who agreed to participate were interviewed and tested for HIV, syphilis, HSV-2, gonorrhoea and chlamydia. We used the Roa-Scott Chi-square test (proportions) and the Student's t test (means) for bivariate comparisons, and adjusted logistic regression models taking into account the cluster effect for multivariate analyses. RESULTS: HIV prevalence decreased significantly in men (3.4% in 1998 versus 2.0% in 2008, p = 0.048), especially in those aged 15-29 (3.0% to 0.5%, p = 0.002). Among men, the prevalence of gonorrhoea decreased significantly (1.1% to 0.3%, p = 0.046) while HSV-2 prevalence increased from 12.0% to 18.1% (p = 0.0003). The proportion of men who reported condom use at least once (29.3% to 61.0%, p<0.0001) and of those having attained a secondary educational level or more (17.1% to 61.3%, p<0.0001) also increased significantly. There was an overall decrease in the prevalence of syphilis (1.5% to 0.6%, p = 0.0003). CONCLUSION: This is the first population-based study reporting a significant decline in HIV prevalence among young men in an African setting where overall prevalence has never reached 5%. The decline occurred while preventive interventions targeting the sex work milieu were ongoing and the educational level was increasing
A clinical prediction score in addition to WHO criteria for anti-retroviral treatment failure in resource-limited settings - experience from Lesotho
No full textOBJECTIVE: To assess the positive predictive value (PPV) of a clinical score for viral failure among patients fulfilling the WHO-criteria for anti-retroviral treatment (ART) failure in rural Lesotho. METHODS: Patients fulfilling clinical and/or immunological WHO failure-criteria were enrolled. The score includes the following predictors: Prior ART exposure (1 point), CD4-count below baseline (1), 25% and 50% drop from peak CD4-count (1 and 2), hemoglobin drop>/=1 g/dL (1), CD4 count/=6 months, 134 (11.8%) had immunological and/or clinical failure, 104 (78%) had blood drawn (13 died, 10 lost to follow-up, 7 did not show up). From 92 (88%) a result could be obtained (2 samples hemolysed, 10 lost). Out of these 92 patients 47 (51%) had viral failure (>/=5000 copies), 27 (29%) viral suppression (/=5. A score>/=5 had a PPV of 100% to detect a VL>40 copies (95%CI: 84-100), and of 90% to detect a VL>/=5000 copies (70-97). Within the score, adherence/=5 and 4 (5%) if score/=5 among patients fulfilling WHO-criteria had a PPV of 100% for a detectable VL and 90% for viral failure. In settings without regular access to VL-testing, this PPV may be considered high enough to switch this patient-group to second-line treatment without confirmatory VL-test