Objective:To study the distribution and abundance of Biomphalaria(B.)pfeifferi species in the Mwea Irrigation Scheme,their role as intermediate hosts for Schistosoma(S.)mansoni,and the impact of water parameters.Metho...Objective:To study the distribution and abundance of Biomphalaria(B.)pfeifferi species in the Mwea Irrigation Scheme,their role as intermediate hosts for Schistosoma(S.)mansoni,and the impact of water parameters.Methods:A longitudinal field survey was conducted across eight administrative wards and five habitat types using a time-based metal scoop method.Physicochemical water quality parameters were measured both in situ and in the laboratory.The snails were examined for S.mansoni infections by shedding method,and cercariae were identified microscopically.Species identification was also performed.The data was analyzed using ANOVA,regression analysis,and Pearson correlation to identify the association between water physiochemical parameters and Biomphalaria snail abundance.Level of significance was determined at 5%(P≤0.05)with 95%confidence limit.Results:A total of 2013 Biomphalaria species were collected,mainly from Murinduko and Nyangati Wards.Streams(965,47.93%)and tertiary canals(676,33.58%)showed the highest abundance.Biomphalaria species populations were recorded in September 2022(1225),with declines noted in February and August 2023.Snail abundance was significantly and positively correlated with pH(β=27.22,P<0.001),turbidity(β=1.117,P=0.008),and total nitrate(β=71.4,P=0.04),and negatively correlated with conductivity,temperature,total dissolved solids,salinity,and dissolved oxygen.No S.mansoni infections were detected;however,69.95%of snails were infected with echinostome cercariae.B.pfeifferi was the dominant species.Sequence analysis revealed genetic diversity,with five NCBI reference sequences forming a distinct clade from the study samples.Conclusions:B.pfeifferi populations showed seasonal variation and strong environmental associations,emphasizing the need for ecological monitoring in schistosomiasis control.展开更多
文摘Objective:To study the distribution and abundance of Biomphalaria(B.)pfeifferi species in the Mwea Irrigation Scheme,their role as intermediate hosts for Schistosoma(S.)mansoni,and the impact of water parameters.Methods:A longitudinal field survey was conducted across eight administrative wards and five habitat types using a time-based metal scoop method.Physicochemical water quality parameters were measured both in situ and in the laboratory.The snails were examined for S.mansoni infections by shedding method,and cercariae were identified microscopically.Species identification was also performed.The data was analyzed using ANOVA,regression analysis,and Pearson correlation to identify the association between water physiochemical parameters and Biomphalaria snail abundance.Level of significance was determined at 5%(P≤0.05)with 95%confidence limit.Results:A total of 2013 Biomphalaria species were collected,mainly from Murinduko and Nyangati Wards.Streams(965,47.93%)and tertiary canals(676,33.58%)showed the highest abundance.Biomphalaria species populations were recorded in September 2022(1225),with declines noted in February and August 2023.Snail abundance was significantly and positively correlated with pH(β=27.22,P<0.001),turbidity(β=1.117,P=0.008),and total nitrate(β=71.4,P=0.04),and negatively correlated with conductivity,temperature,total dissolved solids,salinity,and dissolved oxygen.No S.mansoni infections were detected;however,69.95%of snails were infected with echinostome cercariae.B.pfeifferi was the dominant species.Sequence analysis revealed genetic diversity,with five NCBI reference sequences forming a distinct clade from the study samples.Conclusions:B.pfeifferi populations showed seasonal variation and strong environmental associations,emphasizing the need for ecological monitoring in schistosomiasis control.
