Surveillance and control of post-transmission schistosomiasis in Jiaxing prefecture, Zhejiang province, China.

A surveillance system has been put in place in the Zhejiang province since achieving there the criteria for transmission interruption of schistosomiasis japonica. Suspected patients and special high-risk groups (e.g. the so called 'floating population' and children under 14 years of age) are screened for Schistosoma japonicum using serological tests. Those with positive serological result are subjected to faecal examination and if S. japonicum eggs are found they are treated with praziquantel and followed by regular re-examination until complete cure, i.e. absence of S. japonicum eggs in faecal samples. Patients with advanced schistosomiasis japonica are continuously followed-up. Implementation of the surveillance system from 1995 to 2002 detected two S. japonicum-infected persons; one came from Anhui province and the other from Jiangsu province, but no new infection occurred among local residents. The number of patients with advanced schistosomiasis japonica decreased from 1524 in 1995 to 906 by the end of 2002; a reduction of 40.6%. However, post-transmission schistosomiasis still continues to weigh on the medial resources. We conclude that the surveillance system in Zhejiang province is effective and a useful means for monitoring the endemic situation of schistosomiasis. Hence, it is recommended to be pursued in the years to come.