in Chiggers and Small Mammals in Laos.

Abstract

Scrub typhus is a leading cause of febrile illness in Laos and accounts for a high burden of disease. There have been no previous studies on the causative agent,, in vector mites ("chiggers") or their small mammal hosts in Laos.Small mammals and free-living chiggers were trapped in districts of Vientiane Province and Capital. Tissues were tested forby PCR and serum for IgG toby immunofluorescence assays (IFAs). Chiggers removed from small mammals and collected in their free-living stage using black plates were identified and tested forby PCR.Over an 18-month period, 131 small mammals of 14 species were collected in 5 districts. Seventy-eight of 131 small mammals were infested with chiggers, but all tissues werePCR negative. Eighteen species of chigger were identified and 1,609 were tested by PCR. A single pool of chiggers testedpositive. Sera from 52 small mammals were tested by IFA, with 16 testing positive.These are the first molecular and serological data onin chiggers and small mammals in Laos. Further studies are needed to better understand the key vector species and ecology of scrub typhus in areas with high disease incidence in Laos.