Scrub typhus in northern Thailand: a seroprevalence study among Thai and highland populations

Scrub typhus is a significant cause of febrile illness in Southeast Asia, particularly in northern Thailand. Researchers conducted a population-based study in Chiang Rai province during 2022-2023, testing 1,194 adult participants for antibodies against the bacterium Orientia tsutsugamushi. Seroprevalence was significantly higher among highland people compared to Thai participants (60% versus 13%). In both groups, seropositivity increased with age. Among Thai participants, exposure to forests and agroforestry plantations was associated with higher infection risk, while this relationship was not confirmed in the highland population. High-risk occupations were associated with increased risk in both groups. The study found that current preventive strategies may have limited effectiveness in these high-risk communities.