The epidemiology of schistosomiasis in the later stages of a control programme based on chemotherapy: the Basrah study. 2. The serological profile and the validity of the ELISA in seroepidemiological studies.

An epidemiological study of Schistosoma haematobium infection in Al-maadan locality, considered to be the main remaining endemic focus in Basrah, southern Iraq was carried out. The association between the serological profile of the population, measured by the enzyme linked immunosorbent assay (ELISA), and various factors including current infection by urine examination, water contact pattern, past history of, and treatment for, schistosomiasis, and cercarial dermatitis was investigated. Further study of the serological data by the relative operating characteristic (ROC) analysis to assess the validity of the ELISA in detecting schistosomal infection, showed that current infection, past history of infection, age, cercarial dermatitis and category of household were significantly associated with the serological profile of the population. The analysis allowed quantification of the effects of past history of infection and cercarial dermatitis on the validity of the ELISA in detecting schistosomiasis.