Scrub typhus

Abstract

Scrub typhus is an important emerging tropical infection that can have severe manifestations in children leading to intensive care admission. It is caused by Orientia tsutsugamushi, a gram negative bacterium transmitted to humans by the bite of larval trombiculid mites. The organism is endemic in south-east Asia and the disease is reported from virtually all parts of India. The hallmark of this infection is vasculitis and endothelial injury with intense inflammatory response involving myocardium, pulmonary, nervous and hematological systems. Children present often in post-monsoon season with undifferentiated fever and various degrees of organ involvement that progress to fatal multi organ failure if untreated. Presence of an eschar can be a vital diagnostic clue. Common laboratory features include thrombocytopenia, elevated transaminases and hypoalbuminemia. The diagnosis is confirmed by detection of IgM antibodies by IFA and ELISA or by PCR based assays. Definitive treatment with doxycycline or azithromycin and aggressive supportive care including ventilation, hemodynamic support, and management of AKI and raised intracranial pressure are the mainstay. The mortality ranges from 6-15%, which currently on the improving trend due to better case identification and early initiation of antibiotics along with intensive care.