Scrub typhus: an underestimated endemic disease of Northwestern Himalayas, India

Scrub typhus is a vector-borne rickettsial zoonotic disease, endemic to South Eastern and Far Eastern Asian countries and northern Australia. It is an acute febrile illness, associated with rash and often an eschar, a black crust-like skin lesion. Orientia tsutsugamushi, etiological agent of scrub typhus infects the endothelial cells causing vasculitis, multiple organ dysfunction, life threatening complications and mortalities. Scrub typhus is endemic in Himalayan/sub-Himalayan regions. This review summarizes the status of scrub typhus in mountainous states of India, i.e. Himachal Pradesh, Uttarakhand and Jammu and Kashmir, located in Northwestern Himalayas. Scrub typhus is a major cause of acute febrile illness, fever of unknown origin and febrile jaundice in this region. Disease has been reported both as mono-infection and co-infections with dengue, leptospirosis, malaria and hepatitis from these states. Pediatric scrub typhus cases with neurological complications are common in this region. Agricultural or farming activities are the primary risk factors for the occurrence of scrub typhus in both rural and urban population. Early presentation of the cases and timely diagnosis and treatment of patients is crucial to prevent life threatening complications and deaths. Scrub typhus mimics epidemiology and clinical course of commonly reported infectious diseases and requires differential diagnosis. Therefore, it is imperative to make health workers aware about its manifestations for early diagnosis and treatment and accurate prevalence estimations.