A survey of helminth infection in rats (Rattus spp) from Chiang Mai Moat.

An investigation of helminths in the Norway (brown) rat, Rattus norvegicus, and roof rat, Rattus rattus, from Chiang Mai Moat during May to August 1995, was done. Thirty-three out of thirty-eight trapped rats were infected (86.84%); 16 R. norvegicus (100%) and 17/22 R. rattus (77.27%). The rat was infected with 10 helminth species: 4 trematodes, Centrocestus sp (2.63%), Echinostoma ilocanum (10.52%), Echinostoma malayanum (10.52%) and Quinqueseralis quinqueseralis (39.47%); 2 cestodes, Raillietina sp (36.64%) and Taenia sp (cysticercus) (7.89%); and 4 nematodes, Angiostrongylus cantonensis (42.10%). Nippostrongylus sp (34.21%), Rictularia sp (52.63%) and egg of Capillaria hepatica (7.89%). The helminths were found in the small intestine (84.21%), large intestine (42.10%), lung (36.64%), stomach (28.94%), heart (23.94%), and liver (15.78%). The female Norway rats were infected with 10 species of helminths and the males with 6 species. In the roof rat, 7 species of helminths were found in females and 6 species in males.