Scrub Typhus in South India: a Re-Emerging Infectious Disease

Abstract

Scrub typhus (ST) caused by Orientia tsutsugamushi and transmitted by chiggers of trombiculid mites is an important emerging infectious disease in India. Without early intervention, ST is known to cause serious complications and high morbidity; thus, awareness of this disease among physicians and availability of serological kits can contribute to the control of this rickettsiosis. A serological survey conducted in the 1970s revealed the prevalence of ST in few parts of India (1); however, outbreaks and cases of ST started to appear in several states during the last 10 years, some of which occurred in unanticipated areas (2-18). ST outbreak in 28 adults from October 2001 to February 2002 was first reported in Vellore, Tamil Nadu (3). From the Union Territory of Pondicherry (South India), 50 cases of ST (mostly adults) were recorded by Vivekanandan et al. ( After a gap of 4 years, we encountered 26 presumptive ST cases in adults during 5-month period (November 2011-March 2012). During the same period, we encountered 40 presumptive ST cases in children (19). Hence, there exists a possibility of the re-emergence of ST in this part of South India. This preliminary communication of 26 presumptive adult ST cases within a short period of 5 months is aimed at alerting physicians so that these cases in the Asian community are not dismissed as cases of fever of unknown origin (FUO).