RESUMO
Since the primary objective of mass chemotherapy in schistosomiasis control is reduction of schistosome-induced morbidity, it would be reasonable to assess the impact of a control program on the morbidity in a given population by investigating hepato-splenomegaly associated with schistosomiasis in a schistosomiasis endemic area. In this paper, the authors described the relationship between the prevalence, intensity and morbidity of Schistosoma japonicum infection in terms of stool egg count and ultrasonographically detectable hepatosplenomegaly in a community-based study. It was found that the epidemiological pattern of the infection in this study community was quite different from our usual understanding, that is, the prevalence remained relatively high (39.4%) when the intensity became lower. This unusual pattern might be resulted from intermittent and sporadic chemotherapy associated with frequent exposure of people to the infection in an area of high transmission. It was surprised to note that despite the praziquantel treatment carried out over the past years, the prevalence of hepatosplenomegaly induced by schistosomiasis in this community was still very high, suggesting that intermittent and sporadic chemotherapy might render little impact on schistosomiasis-induced morbidity. The investigation also showed that ultrasonography was a sensitive tool for assessing morbidity associated with schistosome infection.
