OCCURRENCE OF ORIENTIA TSUTSUGAMUSHI IN SMALL MAMMALS FROM THAILAND

Abstract. Extensive sampling of small mammals was conducted in eight provinces of Thailand between September 9, 1992 and April 29, 2001. A total of 3,498 specimens representing 22 species were collected. Eighty-eight percent (3,089 of 3,498) of the animals were collected from a region in Chiangrai Province, which is commonly recognized as endemic for human scrub typhus. Blood and tissue samples from each animal were tested for the presence of Orientia tsutsuga-mushi, the etiologic agent of scrub typhus. The predominant species collected were Rattus rattus (53%, n 1,863), R. losea (18%, n 638), Bandicota indica (16%, n 564), and R. exulans (4%, n 146). Orientia tsutsugamushi was detected in 10 of the 22 species of mammals that included R. bukit (25 % infected, 1 of 4), R. rattus (23%, 419 of 1,855)