Rickettsia tsutsugamushi isolations were attempted from blood samples obtained from rats captured in four adjacent habitats near Kuala Lumpur, Malaysia. Antibody surveys were also made. Rickettsial infections were most frequent in rats captured in the forest and in lalang grass (Imperata cylindrica) and least frequent in the most extensively disturbed habitat, an Orang Asli (aborigine) village. Forest rats such as Rattus sabanus (31%), as well as rats in the subgenus R. (Rattus), i.e. R. tiomanicus (26%) and R. argentiventer (35%) had frequent active infections. The house rat R. exulans had less frequent infections (15%). Frequency of antibody occurrence followed a similar pattern. No marked seasonal differences in the frequency of infections could be detected during the 18-month study.
Rodents were collected from five wet markets (Chow Kit, Dato Keramat, Setapak, Jinjang and Kepong) in Kuala Lumpur, Federal Territory between March to April 2006. Ninety seven rats were trapped using wire traps measuring 29 x 22 x 50 cm baited with fruits, coconuts, dried fish or sweet potatoes. A total of 17 different species of parasites were identified from three species of rats out of which 11 (65%) were identified to be zoonotic. The helminths identified from the urban rats were nematodes- Capillaria hepatica, Gongylonema neoplasticum, Heterakis spumosa, Heterakis sp., Masterphorus muris, Nippostrongylus brasiliensis, Physolaptera sp., Pterogodermatis sp., Rictularia tani and Syphacia muris; cestodes- Hymenolepis nana, Hymenolepis diminuta, Hymenolepis sabnema, Hymenolepis sp., Raillietina sp. and Taenia taeniaeformis, and acanthocephalan- Moniliformis moniliformis. The following parasites are of potential medical importance: C. hepatica, G. neoplasticum, R. tani, S. muris, H. diminuta, H. nana, Raillietina sp. and T. taeniaeformis.