Dengue, Scrub Typhus, And Leptospirosis Among Patients with Acute Febrile Illness in Western Uttar Pradesh, India

Abstract

Background: Acute undifferentiated febrile illnesses (AFIs) present a significant diagnostic challenge in India, particularly during the monsoon and post-monsoon seasons when multiple endemic pathogens circulate simultaneously. The concurrent circulation of Dengue virus, Orientia tsutsugamushi, and Leptospira spp. complicates clinical management, as these pathogens often share overlapping symptomatic profiles, particularly AFI, that obscure differential diagnosis between arboviral and non-arboviral diseases. This diagnostic ambiguity is further exacerbated by the increasing prevalence of coinfection, which often manifests with more severe clinical markers than single-pathogen infections.

Methods: This retrospective, hospital-based investigation analyzed the serological findings from patients presenting with AFI at a tertiary care centre in Western Uttar Pradesh. Diagnostic laboratory procedures utilized IgM ELISA testing for Leptospira and O. tsutsugamushi, alongside ELISA for Dengue NS1 antigen and IgM antibodies.

Results: The analysis revealed that 56.8% of the study cohort exhibited serological evidence of at least one or more than one infection, with dengue being the most frequent monoinfection presentation (40.9%). Alongside, combination of dengue and scrub typhus (6.8%) representing the concurrent infection made an important observation.

Conclusions: The study highlights that other than coinfection of arboviral infections, non-arboviral infections, particularly among patients presenting with acute undifferentiated fever, is often an overlooked concern. This silently complicates clinical management and thus necessitates integrating comprehensive diagnostic panels into routine clinical practice to mitigate the morbidity associated with these emerging zoonotic and vector-borne synergistic infections.