Mansonic schistosomiasis is the main cause of portal hypertension in Brazil. Hepatosplenic (HS) form is manifested by hepatomegaly mainly on the left hepatic lobe associated with large splenomegaly and bleeding due to...Mansonic schistosomiasis is the main cause of portal hypertension in Brazil. Hepatosplenic (HS) form is manifested by hepatomegaly mainly on the left hepatic lobe associated with large splenomegaly and bleeding due to esophageal varices with high mortality rates.展开更多
Mapping and diagnosis of infections by the three major schistosome species(Schistosoma haematobium,S.mansoni and S.japonicum)has been done with assays that are known to be specific but increasingly insensitive as prev...Mapping and diagnosis of infections by the three major schistosome species(Schistosoma haematobium,S.mansoni and S.japonicum)has been done with assays that are known to be specific but increasingly insensitive as prevalence declines or in areas with already low prevalence of infection.This becomes a true challenge to achieving the goal of elimination of schistosomiasis because the multiplicative portion of the life-cycle of schistosomes,in the snail vector,favors continued transmission as long as even a few people maintain low numbers of worms that pass eggs in their excreta.New mapping tools based on detection of worm antigens(circulating cathodic antigen-CCA;circulating anodic antigen-CAA)in urine of those infected are highly sensitive and the CAA assay is reported to be highly specific.Using these tools in areas of low prevalence of all three of these species of schistosomes has demonstrated that more people harbor adult worms than are regularly excreting eggs at a level detectable by the usual stool assay(Kato-Katz)or by urine filtration.In very low prevalence areas this is sometimes 6-to10-fold more.Faced with what appears to be a sizable population of“egg-negative/worm-positive schistosomiasis”especially in areas of very low prevalence,national NTD programs are confounded about what guidelines and strategies they should enact if they are to proceed toward a goal of elimination.There is a critical need for continued evaluation of the assays involved and to understand the contribution of this“egg-negative/worm-positive schistosomiasis”condition to both individual morbidity and community transmission.There is also a critical need for new guidelines based on the use of these more sensitive assays for those national NTD programs that wish to move forward to strategies designed for elimination.展开更多
文摘Mansonic schistosomiasis is the main cause of portal hypertension in Brazil. Hepatosplenic (HS) form is manifested by hepatomegaly mainly on the left hepatic lobe associated with large splenomegaly and bleeding due to esophageal varices with high mortality rates.
基金The authors received financial support from the University of Georgia Research Foundation,Inc.,which was funded by the Bill&Melinda Gates Foundation for the SCORE projectThe funders had no role in the study design,data collection and analysis,decision to publish or preparation of the manuscript.
文摘Mapping and diagnosis of infections by the three major schistosome species(Schistosoma haematobium,S.mansoni and S.japonicum)has been done with assays that are known to be specific but increasingly insensitive as prevalence declines or in areas with already low prevalence of infection.This becomes a true challenge to achieving the goal of elimination of schistosomiasis because the multiplicative portion of the life-cycle of schistosomes,in the snail vector,favors continued transmission as long as even a few people maintain low numbers of worms that pass eggs in their excreta.New mapping tools based on detection of worm antigens(circulating cathodic antigen-CCA;circulating anodic antigen-CAA)in urine of those infected are highly sensitive and the CAA assay is reported to be highly specific.Using these tools in areas of low prevalence of all three of these species of schistosomes has demonstrated that more people harbor adult worms than are regularly excreting eggs at a level detectable by the usual stool assay(Kato-Katz)or by urine filtration.In very low prevalence areas this is sometimes 6-to10-fold more.Faced with what appears to be a sizable population of“egg-negative/worm-positive schistosomiasis”especially in areas of very low prevalence,national NTD programs are confounded about what guidelines and strategies they should enact if they are to proceed toward a goal of elimination.There is a critical need for continued evaluation of the assays involved and to understand the contribution of this“egg-negative/worm-positive schistosomiasis”condition to both individual morbidity and community transmission.There is also a critical need for new guidelines based on the use of these more sensitive assays for those national NTD programs that wish to move forward to strategies designed for elimination.
