Prevalence of Schistosomiasis Japonica among Schoolchildren and Animal Reservoirs in Oriental Mindoro, Philippines.

A survey was conducted in Oriental Mindoro, Philippines in 1997 and 1998 for the purpose of estimating the current situation of schistosomiasis japonica in the area. The prevalence rate in schoolchil dren determined by enzyme-linked immunosorbent assay detecting the parasite egg-specific immuno-globulin G revealed that the disease was more highly endemic in Malabo (70.7%) than in the other villages studied (31.8% in San Pedro and 36.4% in San Narciso), in spite of the fact that all of these villages were located near to each other. The prevalence rates determined by stool examination or necropsy of animal reservoirs in San Pedro, San Narciso and Malabo were as follows; dogs : 9.7%, 7.4% and 19.2%; rats : 10.4%, 8.7% and 26.1%, respectively. Water buffaloes were all negative in all villages. These results showed that the prevalences of schistosomiasis japonica in animal reservoirs have intimate correlation with that in schoolchildren. In Malabo, the colonies of intermediate-host snails were located very close to the resident area, which might be the major cause of high prevalence of the disease.