Dengue and scrub typhus co-infection in children: Experience of a teaching hospital in an endemic area.

Background: Dengue fever and scrub typhus are considered an endemic disease in the Indian subcontinent. The epidemiology and clinical presentations are complex and vary each year.

Objective: The objective of this study was to estimate the prevalence of coinfection with scrub typhus in children diagnosed with dengue fever.

Methods: A retrospective hospital-based, cross-sectional study was done in the Department of Pediatrics of a teaching hospital in Puducherry. All children (0-14 years) who had enzyme-linked immunosorbent assay (ELISA) reported scrub typhus among those diagnosed with dengue fever (NS1Ag or immunoglobulin M ELISA positivity) during 2012-2016. Medical records with incomplete data were excluded from the study. Odds ratio was calculated to find out the association of coinfections. An independent t-test was used to find out the statistical significance. P < 0.05 was considered statistically significant.

Results: Atypical features of dengue were present in 250/318 (78.6%) children. Coinfections were seen in 62/318 (19.4%) children. Scrub typhus was the most common (n = 51/62, 82.2%). The chance of scrub typhus in a dengue serology-positive child is significant when the symptoms are atypical or protracted (OR- 2.6, P = 0.033).

Conclusion: High index of suspicion should be present in endemic dengue and scrub typhus coinfection.