Scrub Typhus – A Threatening Scenario in North Bengal

BACKGROUND Scrub typhus is a mite borne zoonotic bacterial disease caused by Orientia tsutsugamushi. It is transmitted by bite of chiggers of trombiculid mite. Clinical features generally include fever, headache, and myalgia, with or without eschar/rash. People with severe illness may develop organ failure and bleeding which can be fatal if left untreated. This study was done to detect outbreak of cases of scrub typhus in Eastern India. These mites generally live in paddy fields of forested area and people visiting those areas are generally affected. Now a days these mites migrate to urban area resulting in increased incidence of scrub typhus infection in urban area. This study was conducted in collaboration with another institute. The purpose of this study was to find out the incidence of scrub typhus in our area and the relationship between occurrence of scrub typhus and seasonal, age and sex variation. METHODS This study was carried out in our tertiary care hospital with 441 samples for a period of one year (01.01.2019 to 31.12.19). All the blood samples collected from febrile patients were subjected to Weil Felix test. If the titre is > 1 : 160; this was further confirmed by specific IgM testing. Both Weil-Felix tests and IgM scrub typhus positive tests were noted. RESULTS Out of 441 samples, 98 (22.2 %, n = 441) samples were positive for both WeilFelix and scrub typhus IgM by enzyme linked immunosorbent assay (ELISA) testing. Most of the cases were seen in males. Seasonal distribution showed higher cases in the months of September and October. CONCLUSIONS In our study, the highest numbers of scrub typhus cases were found in rural areas, during the harvesting period of July–September specially in monsoon or post monsoon period when there is abundance of mite larva. This infection is also reported high in cases among children in the age group of 1 - 14 years. Patients who tested positive for scrub typhus improved radically with doxycycline. KEYWORDS Orientia Tsutsugamushi, Scrub Typhus, IgM ELISA