Serum samples were send to AFRIMS for diagnostic tests for the most likely pathogens: PCR for dengue viruses and indirect immunofluorescent assay and dot ELISA for rickettsioses (10,11) (Table 1).
To control the scrub typhus outbreak, AFRIMS applied an established prevention and control program, the AFRIMS-Nawamintharachini model, which was established in 2003 after a scrub typhus outbreak in Bo Thong District.
A total of 168 samples (53 from 2004, 19 from 2005, and 96 from 2006) were delivered to AFRIMS for confirmatory dengue testing.
A total of 168 samples from persons suspected to have dengue were tested at AFRIMS. DENV infection was confirmed by PCR or EIA for 34 (64%) of 53 samples from 2004, 12 (63%) of 19 samples from 2005, and 57 (59%) of 96 samples from 2006 (combined 103 [61%] of 168 positive).
AFRIMS identified 14 of 28 serologic samples as positive for O.
Because health officials and the island leadership have been proactive in controlling the scrub typhus situation through rodent control and vegetation clean-up on Gadhdhoo Island, only two rodents were trapped (14) by local officials, both which were identified by AFRIMS as Rattus remotus.
Torugsa is a research scientist at the Armed Forces Research Institute of Medical Sciences (
AFRIMS) in Bangkok, Thailand.