Sero-epidemiological survey of scrub typhus.

A total of 1017 human sera from ecologically different areas in the states of Rajasthan and Jammu & Kashmir were subjected to the CF test using the Gilliam strain antigen of R. tsutsugamushi. Results revealed that 2.4% and 3.5% of the populations examined in the two states respectively, were found to possess antibodies to the test antigen. The titres of positive sera varied from 1:8 to 1:32. Findings of this survey could be correlated with the local topography, presence or absence of vector and the exposure of susceptible population to the rickettsial agent. However, the presence of hidden foci in the neighbouring areas not covered by the current survey cannot be ruled out.