Prevalence Over the Years

Schistosoma japonicum, the only schistosome species in the Philippines, was first described in 1906 among patients at the Philippines General Hospital and among inmates of a Manila prison [1]. In 1937, Onchomelania quadrasi was identified as the intermediate host of S. japonicum in the Philippines, and mapping projects to locate transmission sites commenced. Such studies revealed that schistosomiasis represented a major threat to public health, and that the known foci of transmission were located in rice-growing areas with no dry season on the islands Leyte, Samar and Mindanao [2]. Research into the distribution and morbidity of schistosomiasis paused during WWII, but an epidemic amongst American and Allied Forces on Leyte island brought the problem back to attention in 1944, and the Department of Health (DOH) resumed mapping by 1951 [1]. New endemic areas have been identified as recently as 2003, when two new foci in two previously unidentified regions were discovered in the North, outside the expected range for Oncomelania snails [3]. A History of Schistosomiasis in the Philippines