Analysis of social factors and human behavior attributed to family distribution of schistosomiasis japonica cases.

ABSTRACT

An investigation of family distribution patterns of schistosomiasis japonica was carried out in four pilot villages in Yunnan Province. Family clustering of the disease was present in Bihuayuan Village before and after economic reform (site A); however, such clustering did not occur in Tuanshan and Liantie Villages (sites B and C) in the same periods. Being contrary to the stage prior to economic reform family clustering existed in Zhonghe Village (site D) after the reform. The results obtained from single- and multifactor analysis showed that the main human behavior related to family distribution of schistosomiasis in mountainous regions of Yunnan Province included the frequency of laborer migration, contact with cercariae-infested water in public places or family microenvironments with a high transmission potential, promiscuous defecation and status of cattle grazing. The frequency of laborer migration and human contact with cercariae-infested water in public places in sites B and C without family clustering was higher than that in sites A and D with family clustering. Place for promiscuous defecation and cattle grazing in site A converged compared with that in sites B and C.