Clinicolaboratory Profile and Outcome of Serologically Confirmed Scrub Typhus among Children from Sub Himalayan Tribal District of India: A Hospital-based Cross-sectional Study

Abstract

Introduction: Scrub typhus is transmitted by the bite of the larva (chigger) of a microscopic trombiculidae mite (Leptotrombidium) found in moist areas and vegetation, which serves as both vector and reservoir. Scrub typhus is an often neglected and misdiagnosed febrile illness; clinical suspicion is the only key to diagnosis. Aim: To study clinicolaboratory profile and outcome of serologically confirmed scrub typhus in children from sub Himalayan tribal district of India. Materials and Methods: This cross-sectional observational study was conducted in Department of Paediatrics at Government District Hospital, Chamba, Himachal Pradesh, India, from May 2019 to April 2020. Children upto 18 years admitted with positive Immunoglobulin M (IgM) antibodies for scrub typhus were enrolled. The observational data including detail history and examination, relevant laboratory investigation and treatment was analysed by Statistical Package for Social Sciences (SPSS) software version 18.0 and Chi-square test with p-value <0.05 was considered statistically significant. Results: There were total 55 patients with scrub typhus, mean age was 9.2 years, most common age group was 7-12 years, 51% were male. Fever was most common complaint, followed by vomiting (27.3%), abdomen pain (25.4%), respiratory (1.8%), and rash (9%). Clinical examination findings were generalised lymphadenopathy in 46 (83.6%) patients and splenomegaly in 29 (52.7%). Eight patients presented with respiratory signs and tachypnea at the time of admission. Eschar was present in only 3 (5.5%) patients. Sign of meningeal irritation was present in 4 (7.3% cases and low GCS score (below 9) observed in 7 (12.7%) patients. Eight patients required mechanical ventilatory support. Nineteen patients were prescribed doxycycline alone; while 34 were given both azithromycin and doxycycline. There were total five deaths; on multivariate logistic regression, respiratory complaint, need for mechanical ventilation, pain abdomen with liver damage, history of seizures and duration of fever more than 4 days before presentation to hospital were associated with adverse outcome. Conclusion: The prevalence of scrub typhus is considerably high during rainy season, and should be considered as a differential diagnosis of fever among children in this period regardless of the presence of an eschar. Immediate medical care, treatment with doxycycline with early defervescence of fever reduce mortality