A Clinico-Epidemiological Study of Scrub Typhus Cases in a Tertiary Care Center of a Non-endemic Area

TL;DR

This study examines the clinical and epidemiological features of scrub typhus in a non-endemic area, highlighting its diagnostic challenges and high mortality.

Contribution

The study identifies predictors of mortality and emphasizes the need for early treatment in non-endemic regions.

Findings

Scrub typhus cases in non-endemic areas often present with non-specific symptoms like cough and altered sensorium.

Multiple organ dysfunction and acute respiratory distress syndrome are common complications with high mortality.

Encephalopathy and shock are independent predictors of death in scrub typhus patients.

Abstract

Background

Scrub typhus is a re-emerging mite-borne rickettsial infection, traditionally endemic to hilly regions with scrub vegetation, with an emerging spread into non-endemic areas. Given its common presentation as acute undifferentiated febrile illness (AUFI), it often remains underdiagnosed in these areas, even by astute physicians. The study was undertaken to evaluate the socio-epidemiological and clinical characteristics, including complications and mortality, of scrub typhus in a non-endemic region.

Methodology

This retrospective study included 64 patients diagnosed with scrub typhus using an IgM enzyme-linked immunosorbent assay. Medical records were reviewed for seasonal patterns, presentations, and predictors of mortality.

Results

The seroprevalence rate was 15.6% among the tested patients. Cases occurred predominantly between August and November. Common presentations included cough and dyspnea (43.8%), gastrointestinal symptoms (26.5%), and altered sensorium (14.0%). Eschar was observed in only 4.6% of cases. Multiple organ dysfunction syndrome developed in 37.5%, with one-third mortality among these patients. Acute respiratory distress syndrome occurred in 26.5%. Laboratory abnormalities included transaminitis (59.3%), jaundice (28.0%), and acute kidney injury (26.5%). Overall mortality was 14.0%. Encephalopathy and shock were independent predictors of mortality.

Conclusions

Scrub typhus in non-endemic regions presents with significant multi-organ involvement. Low eschar frequency and diverse presentations contribute to diagnostic challenges. Early empirical doxycycline or azithromycin therapy should be considered for AUFI patients to prevent complications from delayed diagnosis.

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