Clinical Characteristics and Predictors of Severity of Pediatric Scrub Typhus in a Tertiary Level Hospital in South India

Background: Scrub typhus, a zoonosis caused by bacteria Orientia tsutsugamushi is associated with varying clinical features and significant mortality due to complication in view of ineffective treatment. Objectives: This study was undertaken to identify the factors for predicting severity in scrub typhus. Methods: This retrospective study was conducted at a tertiary care teaching hospital between January 2015 to October 2016. All children younger than 18 years of age admitted with a history of fever for more than seven days and positive IgM ELISA for scrub typhus were included in the study. Cases of “severe scrub typhus” were identified based on criteria from published pediatric studies. A total of 235 patients tested positive for scrub typhus, out of which 39 patients were in the severe scrub group and 196 in the nonsevere group. Reports were analyzed for the predictors of severity of scrub typhus in both groups. Results: Using multivariate analysis, the factors for predicting severity in scrub typhus were hemoglobin 10 g/L (OR = 2.8, CI = 1.40 to 5.72), platelet 150 000 cells/mm³ (OR = 2.54, CI = 1.21 to 5.30), albumin 2.5 g/d (OR = 3.18, CI = 1.42 to 7.11), SGOT 5 fold rise (OR = 49.7, CI = 13.49 to 183.17), prolongation of PT (P value = 0.03), and altered sensorium (P value = 0.016) were correlated with severe disease. Conclusions: We conclude that altered sensorium, anemia, thrombocytopenia, elevated transaminases, hypoalbuminemia, and prolongation of prothrombin time to be predictors of severity of illness in scrub typhus.