Seroprevalence and clinical manifestations of scrub typhus infection in Chennai city: A cross-sectional study

Abstract

BACKGROUND: Scrub typhus is a zoonotic rickettsial illness caused by Orientia tsutsugamushi and has been reported from Southeast Asia, the Asian Pacific Rim, and Australia. It is an emerging pathogen in Southern India, especially in the urban setting. The objective of this study was to identify scrub typhus infection among febrile patients and to identify clinical manifestations related to the disease. METHODS: In this prospective cross-sectional study, febrile patients who presented to the Department of Experimental Medicine at the Tamil Nadu Dr. M.G.R. Medical University between November 2015 and February 2016 were enrolled. Demographics and clinical manifestations were recorded using a semi-structured questionnaire. Serum was separated from 2 ml of blood sample for testing. The Scrub Typhus Detect ELISA test was performed as per manufacturer's instructions. Statistical data analysis was done. RESULTS: A total of 100 patients were enrolled and their age ranged from 4 to 80 years with a mean of 30 years. Nearly 56% were males. Ig M antibodies for O. tsutsugamushi were present in 23% of cases. Most (65%) of the positive patients were females. About 48% positives for scrub typhus were 4–20 years old. Clinical presentations in these patients were fever (100%), myalgia (73.9%), headache (65.2%), nausea (60.9%), cough (60.9%), abdominal pain (52.2%), vomiting (47.8%), breathlessness (39.1%), diarrhea (34.8%), and decreased urine output (26.1%). Eschar was seen in 7 patients of whom 2 were positive for scrub typhus. CONCLUSIONS: In this study, 23% of febrile patients were positive for scrub typhus infection. Therefore, it needs to be included in the differential diagnosis of febrile illnesses in Chennai city.