OCCURRENCE OF PENICILLIUM-MARNEFFEI INFECTIONS AMONG WILD BAMBOO RATSIN THAILAND

Penicilliosis marneffei has emerged as an endemic systemic mycosis in Southeast Asia among humans and wild bamboo rats. To gain an insight i nto the epidemiology of this life-threatening disease, a survey of bam boo rats for natural infections by Penicillium marneffi was carried ou t in the central plains of Thailand during June-September, 1987. Thirt y-one lesser bamboo rats (Cannomys badius) and eight hoary bamboo rats (Rhizomys pruinosus) were trapped. Portions of their internal organs were cultured to determine if they had been infected by P. marneffei. Six each of C. badius (19.4%) and R. pruinosus (75%) yielded cultures of this unique, dimorphic Penicillium species. All of the isolates wer e readily converted to their unicellular form that multiplies by the p rocess of schizogony by incubating them at 37 degrees C on plates of b rain heart infusion agar. Their identity was further confirmed by a sp ecific immunological test. Among the internal organs of the positive r ats, the lungs had the highest positivity (83.3%), next in decreased o rder of frequency were the liver (33.3%) and the pancreas (33.3%). The use and value of domestic and wild animals in locating and demarcatin g endemic areas of geophilic fungal pathogens are discussed. Penicilli osis marneffei is considered to be a zooanthroponosis - a disease that occurs in lower animals, as well as, humans.