The longevity of antibody to Rickettsia tsutsugamushi in patients with confirmed scrub typhus.

Abstract Serological surveillance for up to two years of 114 patients with laboratory confirmed scrub typhus showed that antibody to Rickettsia tsutsugamushi as demonstrated by the indirect fluorescent antibody test is short-lived. The mean reversion time from mean peak titre (1:499) was 48·9 weeks and the calculated annual reversion rate to a titre