Abstract
We estimated the seroprevalence and determined the frequency of acute infections with Neorickettsia sennetsu, spotted fever group rickettsiae, Rickettsia typhi, and Orientia tsutsugamushi among 2,225 febrile patients presenting to community hospitals in three rural Thailand provinces during 2002-2005. The seroprevalence was 0.2% for sennetsu neorickettsiosis (SN), 0.8% for spotted fever group (SFG) rickettsiae, 4.2% for murine typhus (MT), and 4.2% for scrub typhus (ST). The frequency of acute infections was 0.1% for SN, 0.6% for SFG, 2.2% for MT, and 1.5% for ST. Additional studies to confirm the distribution of these pathogens and to identify animal reservoirs and transmission cycles are needed to understand the risk of infection.