Background: The last decade has seen an expansion of national schistosomiasis control programmes in Africa based on large-scale preventative chemotherapy. In many areas this has resulted in considerable reductions in infection and morbidity levels in treated individuals. In this paper, we quantify changes in the force of infection (FOI), defined here as the per (human) host parasite establishment rate, to ascertain the impact on transmission of some of these programmes under the umbrella of the Schistosomiasis Control Initiative (SCI).
View Article and Find Full Text PDFBackground: Over 1 billion of the world's poorest inhabitants are afflicted by neglected tropical diseases (NTDs). Integrated control programmes aimed at tackling these debilitating NTDs have been recently initiated, mainly using preventative chemotherapy. Monitoring and evaluation (M&E) of these integrated programs presents particular challenges over and above those required for single disease vertical programmes.
View Article and Find Full Text PDFBackground: In the developing world co-infections and polyparasitism within humans appear to be the rule rather than the exception, be it any combination of inter-specific and/or inter- and intra-Genera mixed infections. Mixed infections might generate synergistic or antagonistic interactions and thereby clinically affect individuals and/or impact parasite epidemiology.
Methods: The current study uniquely assesses both Schistosoma mansoni- and Schistosoma haematobium-related morbidity of the liver and the bladder as assessed by ultrasound as well as spleen and liver morbidity through clinical exams.
Objective: To predict the subnational spatial variation in the number of people infected with Schistosoma haematobium in Burkina Faso, Mali and the Niger prior to national control programmes.
Methods: We used field survey data sets covering a contiguous area 2750 x 850 km and including 26,790 school-age children (5-14 years old) in 418 schools. The prevalence of high- and low-intensity infection and associated 95% credible intervals (CrIs) were predicted using Bayesian geostatistical models.
The burden of schistosomiasis in infants and preschool-aged children and their mothers is poorly known. We carried out a cross-sectional epidemiological survey in two villages in Niger: Falmado is endemic for Schistosoma haematobium only, whereas a mixed S. haematobium-S.
View Article and Find Full Text PDFBackground: We investigated changes in the spatial distribution of schistosomiasis in Mali following a decade of donor-funded control and a further 12 years without control.
Methodology/principal Findings: National pre-intervention cross-sectional schistosomiasis surveys were conducted in Mali in 1984-1989 (in communities) and again in 2004-2006 (in schools). Bayesian geostatistical models were built separately for each time period and on the datasets combined across time periods.
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.
We aimed to map the probability of Schistosoma haematobium infection being >50%, a threshold for annual mass praziquantel distribution. Parasitologic surveys were conducted in Burkina Faso, Mali, and Niger, 2004-2006, and predictions were made by using Bayesian geostatistical models. Clusters with >50% probability of having >50% prevalence were delineated in each country.
View Article and Find Full Text PDFBackground: 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.
Burkina Faso, Mali and Niger are countries endemic for schistosomiasis, with a high predominance of Schistosoma haematobium. With the support of the Bill and Melinda Gates Foundation through the Schistosomiasis Control Initiative, national control programmes were launched in these countries in 2004. Here, we describe the progress of implementation for each programme and the challenges for maintaining sustainability for schistosomiasis control in these countries.
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