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Bertrand Sellin

Bio: Bertrand Sellin is an academic researcher from Pasteur Institute. The author has contributed to research in topics: Schistosoma haematobium & Schistosomiasis. The author has an hindex of 18, co-authored 47 publications receiving 1047 citations.

Papers
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Journal ArticleDOI
TL;DR: It is suggested that even a single round of mass chemotherapy can have a substantial impact on S. haematobium infection and its associated morbidity in children in sub-Saharan Africa.
Abstract: Background. In sub-Saharan Africa, 112 million people are infected with Schistosoma haematobium, with the most intense infections in children 5–15 years old. Methods. We describe a longitudinal epidemiological study that evaluates the relationship between S. haematobium infection and associated morbidity in children before and after the large-scale administration of praziquantel for schistosomiasis and albendazole for soil-transmitted helminths. Results. At baseline, higher intensities of S. haematobium infection were observed in children with anemia and/or severe microhematuria, but there was no apparent association between the risk of undernutrition and intensity of S. haematobium infection. Significant reductions in the prevalence and intensity of S. haematobium infection 1 year after treatment were, however, observed. Children who benefited the most from anthelmintic treatment in terms of increased hemoglobin concentrations were those who had anemia at baseline and those with highly positive microhematuria scores at baseline. Conclusions. This study suggests that even a single round of mass chemotherapy can have a substantial impact on S. haematobium infection and its associated morbidity in children.

148 citations

Journal ArticleDOI
TL;DR: Significant and sustained reduction in S. haematobium infection was achieved by biennial treatment in school-age children in Burkina Faso, which may provide a cost-effective treatment strategy for similar national schistosomiasis control programmes in sub-Saharan Africa.
Abstract: Objective To evaluate the impact on schistosomiasis of biennial treatment with praziquantel (PZQ) among school-age children in Burkina Faso, the first country that achieved full national coverage with treatment of more than 90% of the school-age population. Methods A cohort of 1727 schoolchildren (6–14 years old) was monitored at yearly intervals through a longitudinal survey. Additional groups of schoolchildren were monitored in cross-sectional surveys. Parasitological examinations for Schistosoma haematobium and Schistosoma mansoni were performed, and prevalence and intensity of infection before and after treatment were analysed. Findings Data from the longitudinal cohort show that a single round of PZQ treatment significantly reduced prevalence of S. haematobium infection by 87% (from 59.6% to 7.7%) and intensity of infection by 92.8% (from 94.2 to 6.8 eggs/10 ml of urine) 2 years posttreatment. The impact on infection was also confirmed by a cross-sectional survey 2 years post-treatment. Importantly, the proportion of school-age children with heavy S. haematobium infection decreased from around 25% before treatment to around 2–3% 2 years post-treatment. Cross-sectional comparison of S. haematobium infection in 7-year-old children in their first year at school, who received treatment through community-based drug delivery, also showed significant reduction in both prevalence (65.9%) and intensity of S. haematobium infection (78.4%) 2 years after single treatment. A significant reduction in S. mansoni infection was also achieved. Conclusion Significant and sustained reduction in S. haematobium infection was achieved by biennial treatment in school-age children in Burkina Faso. This may provide a cost-effective treatment strategy for similar national schistosomiasis control programmes in sub-Saharan Africa. Bulletin of the World Health Organization 2008;86:780–787.

116 citations

Journal ArticleDOI
TL;DR: Antisera directed against the major Sm28GST epitopes revealed differences in the recognition of the 28-kDa GSTs from the other schistosome species suggesting that these regions have been subjected to evolutionary pressure.

87 citations

Journal ArticleDOI
TL;DR: The relationship between iron status and degree of infection by Schistosoma haematobium was studied in 174 schoolchildren from Niger and shows a deleterious consequence of urinary schistosomiasis on nutrition and hematopoietic status, which should be considered in the design of nutrition intervention programs.
Abstract: The relationship between iron status and degree of infection by Schistosoma haematobium was studied in 174 schoolchildren from Niger in an area endemic for urinary schistosomiasis. Iron deficiency was defined by a combination of three reliable indicators: a low serum ferritin level combined with a low transferrin saturation, a high erythrocyte protoporphyrin level, or both. Hematuria and proteinuria were found in 76.4% and 79.9% of the children, respectively, while 95.4% excreted eggs (geometric mean egg count of 31.5 eggs per 10 ml of urine). Anemia was observed in 59.7% of the subjects. The prevalence of iron deficiency was 47.1%. Anemia was associated with iron deficiency in 57.7% of the cases. The hemoglobin level and transferrin saturation decreased significantly when the degree of hematuria increased, while prevalence of anemia and prevalence of iron deficiency increased significantly. The hemoglobin level and the hematocrit were negatively correlated with egg count, while prevalence of anemia increased with increasing egg count. This inverse relationship between degree of infection by S. haematobium and iron status shows a deleterious consequence of urinary schistosomiasis on nutrition and hematopoietic status, which should be considered in the design of nutrition intervention programs.

62 citations

Journal ArticleDOI
TL;DR: It is concluded that a combined school- and community-based strategy is effective in attaining a high coverage among school-age children in countries where school enrolment is low and where primary schools cannot serve as the exclusive drug distribution points.

59 citations


Cited by
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Journal Article
Fumio Tajima1
30 Oct 1989-Genomics
TL;DR: It is suggested that the natural selection against large insertion/deletion is so weak that a large amount of variation is maintained in a population.

11,521 citations

Journal ArticleDOI
TL;DR: A raised estimate of 2-15% disability seems evident in different functional domains of a person with schistosomiasis, if confirmed in formal patient-preference studies, indicates a need to reassess the authors' priorities for treating this silent pandemic of schistOSomiasis.

836 citations

Journal ArticleDOI
TL;DR: The mechanisms underlying linear growth failure at different ages are described, the short-, medium- and long-term consequences of stunting are discussed, and the evidence for windows of opportunity during the life cycle to target interventions at the stunting syndrome are evaluated.
Abstract: Linear growth failure is the most common form of undernutrition globally. With an estimated 165 million children below 5 years of age affected, stunting has been identified as a major public health priority, and there are ambitious targets to reduce the prevalence of stunting by 40% between 2010 and 2025. We view this condition as a ‘stunting syndrome’ in which multiple pathological changes marked by linear growth retardation in early life are associated with increased morbidity and mortality, reduced physical, neurodevelopmental and economic capacity and an elevated risk of metabolic disease into adulthood. Stunting is a cyclical process because women who were themselves stunted in childhood tend to have stunted offspring, creating an intergenerational cycle of poverty and reduced human capital that is difficult to break. In this review, the mechanisms underlying linear growth failure at different ages are described, the short-, medium- and long-term consequences of stunting are discussed, and th...

683 citations

Book ChapterDOI
TL;DR: In this paper, the origins and geographical spread of F. gigantica and F. hepatica were investigated by means of complete sequences of ribosomal deoxyribonucleic acid (rDNA) internal transcribed spacer (ITS)−2 and ITS−1 and mitochondrial cox1 and nad1 from areas with only one fasciolid species.
Abstract: Fascioliasis, caused by liver fluke species of the genus Fasciola, has always been well recognized because of its high veterinary impact but it has been among the most neglected diseases for decades with regard to human infection. However, the increasing importance of human fascioliasis worldwide has re‐launched interest in fascioliasis. From the 1990s, many new concepts have been developed regarding human fascioliasis and these have furnished a new baseline for the human disease that is very different to a simple extrapolation from fascioliasis in livestock. Studies have shown that human fascioliasis presents marked heterogeneity, including different epidemiological situations and transmission patterns in different endemic areas. This heterogeneity, added to the present emergence/re‐emergence of the disease both in humans and animals in many regions, confirms a worrying global scenario. The huge negative impact of fascioliasis on human communities demands rapid action. When analyzing how better to define control measures for endemic areas differing at such a level, it would be useful to have genetic markers that could distinguish each type of transmission pattern and epidemiological situation. Accordingly, this chapter covers aspects of aetiology, geographical distribution, epidemiology, transmission and control in order to obtain a solid baseline for the interpretation of future results. The origins and geographical spread of F. hepatica and F. gigantica in both the ruminant pre‐domestication times and the livestock post‐domestication period are analyzed. Paleontological, archaeological and historical records, as well as genetic data on recent dispersal of livestock species, are taken into account to establish an evolutionary framework for the two fasciolids across all continents. Emphasis is given to the distributional overlap of both species and the roles of transportation, transhumance and trade in the different overlap situations. Areas with only one Fasciola spp. are distinguished from local and zonal overlaps in areas where both fasciolids co‐exist. Genetic techniques applied to liver flukes in recent years that are useful to elucidate the genetic characteristics of the two fasciolids are reviewed. The intra‐specific and inter‐specific variabilities of ‘pure’ F. hepatica and ‘pure’ F. gigantica were ascertained by means of complete sequences of ribosomal deoxyribonucleic acid (rDNA) internal transcribed spacer (ITS)‐2 and ITS‐1 and mitochondrial deoxyribonucleic acid (mtDNA) cox1 and nad1 from areas with only one fasciolid species. Fasciolid sequences of the same markers scattered in the literature are reviewed. The definitive haplotypes established appear to fit the proposed global evolutionary scenario. Problems posed by fasciolid cross‐breeding, introgression and hybridization in overlap areas are analyzed. Nuclear rDNA appears to correlate with adult fluke characteristics and fasciolid/lymnaeid specificity, whereas mtDNA does not. However, flukes sometimes appear so intermediate that they cannot be ascribed to either F. hepatica‐like or F. gigantica‐like forms and snail specificity may be opposite to the one deduced from the adult morphotype. The phenotypic characteristics of adults and eggs of ‘pure’ F. hepatica and F. gigantica, as well as of intermediate forms in overlap areas, are compared, with emphasis on the definitive host influence on egg size in humans. Knowledge is sufficient to support F. hepatica and F. gigantica as two valid species, which recently diverged by adaptation to different pecoran and lymnaeid hosts in areas with differing environmental characteristics. Their phenotypic differences and ancient pre‐domestication origins involve a broad geographical area that largely exceeds the typical, more local scenarios known for sub‐species units. Phenomena such as abnormal ploidy and aspermic parthenogenesis in hybrids suggest that their separate evolution in pre‐domestication times allowed them to achieve almost total genetic isolation. Recent sequencing results suggest that present assumptions on fasciolid‐lymnaeid specificity might be wrong. The crucial role of lymnaeids in fascioliasis transmission, epidemiology and control was the reason for launching a worldwide lymnaeid molecular characterization initiative. This initiative has already furnished useful results on several continents. A standardized methodology for fasciolids and lymnaeids is proposed herein in order that future work is undertaken on a comparable basis. A complete understanding of molecular epidemiology is expected to help greatly in designing global actions and local interventions for control of fascioliasis.

544 citations

Journal ArticleDOI
TL;DR: An agenda for the elimination of schistosomiasis would aim to identify the gaps in knowledge, and define the tools, strategies and guidelines that will help national control programmes move towards elimination, including an internationally accepted mechanism that allows verification/confirmation of elimination.

500 citations