Post-disaster outbreak of scrub typhus in Sub-Himalayan region of Uttarakhand

Background: In June 2013, flash floods caused a great loss of human life and infrastructure in the Sub-Himalayan region of Uttarakhand, India. An outbreak of scrub typhus caused by Orientia tsutsugamushi occurred in the district of Chamoli, Rudraprayag and Pauri Garhwal after the disaster. The present study was conducted with the objective to describe this outbreak in terms of time, place, person and clinical features and to compare the outbreak with the pre-disaster status of the area. Materials and Methods: This study was conducted in Veer Chandra Singh Garhwali Government Medical Science and Research Institute, Srinagar, Pauri Garhwal from June to December 2013. Study subjects were patients from disaster-affected areas. Definition criteria were used for clinically suspected, probable and confirmed cases of scrub typhus. All the samples were subjected to immunochromatographic test out of which 229 were confirmed by ELISA. Results: A total of 283 samples of patients with undiagnosed fever were tested and 229 (80.9%) showed the presence of IgM antibody by ELISA against scrub typhus. The maximum number of cases (213) were found between July and November and were mainly confined to the districts mentioned above. The main clinical features were gastrointestinal symptoms (53%), rash (51%), myalgia (71%), acute respiratory distress syndrome (ARDS) (2%), hepatorenal syndrome (1.7%), coagulopathy (18%) and eschar occurred only in five cases (2%). Conclusions: An increase in the number of cases of scrub typhus was observed after the floods in Uttarakhand, which suggests that a post-disaster epidemic had occurred. Scrub typhus should also be considered in the differential diagnosis of acute febrile illness with gastrointestinal symptoms, rash, myalgia, ARDS, hepatorenal syndrome and coagulopathy. Eschar being pathognomonic, may not always be seen, and its absence does not rule out scrub typhus.