VOLUME 19 NUMBER 1 (January to June 2026)

Rats from selected communities of Caraga Region, Philippines: Their helminths and potential role as indicators of Schistosoma japonicum transmission

Schistosomiasis is an endemic parasitic disease in the Philippines with reported high prevalence in the Caraga Region. As an agricultural region with abundant rice fields, there is a greater risk of infection because rice fields are favorable transmission environments for schistosomiasis. Rats, commonly present in these rice fields, are possible carriers of zoonotic diseases. This study aimed to describe zoonotic helminths in rats from seven municipalities of Agusan del Sur and Surigao del Norte. Rats were collected using cage traps placed in selected rice fields. Dissection of captured rats, tissue digestion, and coprological techniques were done to recover parasites. Locations of S. japonicum-positive rats were mapped with snail habitats and S. japonicum-positive households to assess possible transmission links. A high percentage of rats (94.6%) harbored helminths such as Capillaria hepatica, Hymenolepis diminuta, Angiostrongylus cantonensis, Echinostoma spp., Taenia taeniaeformis, Raillietina spp., Artyfechinostomum malayanum, Aspicularis tetraptera, Trichuris sp., Syphacia sp., Physaloptera sp., Rictularia spp., and Nippostrongylus sp. Among the 74 rats examined, 39.2% were positive for S. japonicum eggs, with higher occurrence in Agusan del Sur (51.1%). Spatial mapping revealed that most S. japonicum-positive rats were located near infected households and snail sites, thus highlighting their role as schistosomiasis sentinels for identifying areas of active S. japonicum transmission in the environment and the need for integrated One Health approaches for schistosomiasis surveillance and intervention.