Objective: To study the indicators and validity of inquiry in the screening of chronic schistosomiasis japonica.
Methods: 51 villages of Hanshou county were selected at random in Hunan Province and the whole resident (>6 months/year) population aged 5 years and above was eligible for inclusion in the study. Inquiry through questionnairing, serological test (ELISA) and B type ultrasonography were applied respectively to screen chronic cases and evaluate morbidity due to schistosome infection. Logistic analysis was performed to explore the relationship between indicators of questionnaire and the results of ELISA and abdominal ultrasonography. Bayes discriminant analysis was used to assess consistency of inquiry and ELISA, inquiry and the degree of hepatic fibrosis.
Results: 26,426 inhabitants in the endemic villages were screened by ELISA with 1380 (5.2%) positive. 1264 sero-positive and 1446 sero-negative cases were asked questions relating to schistosomiasis and examined by abdominal ultrasonography. Inquiry indices such as self-reported diarrhea, stool with mucus and fatigue during the last two weeks, history of infested water contact and times of treatment were specific to chronic schistosomiasis. The coincident rate for validation was 75.9% between inquiry and ELISA, and 75.4% between inquiry and hepatic fibrosis degree.
Conclusion: Validity of inquiry was satisfactory in screening chronic schistosomiasis in endemic areas.