Background:Schistosomiasis is classically described as a rural disease that occurs in areas with poor sanitary conditions.However,over recent decades,there has been an expansion of schistosomiasis foci towards urban a...Background:Schistosomiasis is classically described as a rural disease that occurs in areas with poor sanitary conditions.However,over recent decades,there has been an expansion of schistosomiasis foci towards urban areas faced with a rapid and disordered urbanization.In Bamako,Mali,the impact of environmental change on vector-borne diseases such as schistosomiasis is not well known.This study sought to identify the presence of schistosomiasis transmission hotspots in Bamako.Using this perspective,we aimed to describe the risk factors of the endemization and maintenance of schistosomiasis.Materials and methods:A cross-sectional study was carried out in the six municipalities(communes)in Bamako.Environmental information was obtained from earth observation satellites in order to maximize ecological contrasts.Twenty-nine blocks of 200 m x 200 m were identified.We selected a school inside or nearest to each block for urine and stool samples examination.The study cohort was school children aged between eight and 15 years.The Kato-Katz technique and filtration were used for Schistosoma mansoni and S.haematobium ova research in stools and urine,respectively.The schools and snail breeding sites were georeferenced.Four malacological surveys were conducted between October 2011 and February 2012.Bivariate analysis was used to identify independent predictors of being infected with schistosomiasis.Results:The prevalence rate of S.haematobium was 14.7%(n=1,761)and that of S.mansoni 1.5%(n=1,491).Overall,the urinary form was endemic in 76.6%of schools.The infection significantly varied between the municipalities(p<0.001).It was also more prevalent on the left side of the Niger River than the right side(17.4%vs.9.5%respectively;p<0.001).The vicinity to snail breeding sites(OR=3.677;95%IC[2.765–4.889];p<10-3)and parents’occupations(OR=7.647;95%IC[2.406–24.305];p<0.001)were the most important risk factors associated with S.haematobium infection exposure.Biomphalaria pfeifferi,Bulinus truncatus,and B.globosus were the intermediate hosts captured.The schistosome natural infection rates(SNIRs),which were low or nil in October and November,rose to 2.8%in January and 8.3%in February for B.pfeifferi and B.truncatus,respectively.Conclusion:Our findings show that there is a high transmission risk for schistosomiasis in Bamako.Appropriate integrated control measures need to be introduced to control the transmission of this disease in the study area.展开更多
基金We acknowledge the generous support provided by the International Mix Unity(UMI)of the National Scientific Research Centre(CNRS)of France,the Academic Centres of the right and left sides of the Niger River,the directors the selected schools,the schoolchildren,the research assistants for their input and dedication to the study,the staff of the Faculty of Pharmacy,and all other persons without whose support this study would not have been possible.
文摘Background:Schistosomiasis is classically described as a rural disease that occurs in areas with poor sanitary conditions.However,over recent decades,there has been an expansion of schistosomiasis foci towards urban areas faced with a rapid and disordered urbanization.In Bamako,Mali,the impact of environmental change on vector-borne diseases such as schistosomiasis is not well known.This study sought to identify the presence of schistosomiasis transmission hotspots in Bamako.Using this perspective,we aimed to describe the risk factors of the endemization and maintenance of schistosomiasis.Materials and methods:A cross-sectional study was carried out in the six municipalities(communes)in Bamako.Environmental information was obtained from earth observation satellites in order to maximize ecological contrasts.Twenty-nine blocks of 200 m x 200 m were identified.We selected a school inside or nearest to each block for urine and stool samples examination.The study cohort was school children aged between eight and 15 years.The Kato-Katz technique and filtration were used for Schistosoma mansoni and S.haematobium ova research in stools and urine,respectively.The schools and snail breeding sites were georeferenced.Four malacological surveys were conducted between October 2011 and February 2012.Bivariate analysis was used to identify independent predictors of being infected with schistosomiasis.Results:The prevalence rate of S.haematobium was 14.7%(n=1,761)and that of S.mansoni 1.5%(n=1,491).Overall,the urinary form was endemic in 76.6%of schools.The infection significantly varied between the municipalities(p<0.001).It was also more prevalent on the left side of the Niger River than the right side(17.4%vs.9.5%respectively;p<0.001).The vicinity to snail breeding sites(OR=3.677;95%IC[2.765–4.889];p<10-3)and parents’occupations(OR=7.647;95%IC[2.406–24.305];p<0.001)were the most important risk factors associated with S.haematobium infection exposure.Biomphalaria pfeifferi,Bulinus truncatus,and B.globosus were the intermediate hosts captured.The schistosome natural infection rates(SNIRs),which were low or nil in October and November,rose to 2.8%in January and 8.3%in February for B.pfeifferi and B.truncatus,respectively.Conclusion:Our findings show that there is a high transmission risk for schistosomiasis in Bamako.Appropriate integrated control measures need to be introduced to control the transmission of this disease in the study area.
