Assessment of chikungunya co-infection in the lab confirmed dengue cases using NS1 antigen and IgM ELISA in western Uttar Pradesh

Abstract

Background: In tropical and subtropical areas, dengue and chikungunya are common viral illnesses spread by Aedes aegypti mosquitoes. Co-infection with both viruses can raise the burden of disease, change clinical symptoms, and delay diagnosis. Recent years have seen frequent outbreaks of both illnesses in Western Uttar Pradesh
Aim: To assess the prevalence and pattern of chikungunya co-infection among laboratory-confirmed dengue cases using NS1 antigen and IgM ELISA at Shaikh-Ul-Hind Maulana Mahmood Hasan Medical College.
Methods: The Department of Microbiology carried out this retrospective observational study between April 2024 and March 2026. Patients who had been tested for dengue and chikungunya had their laboratory data examined. IgM ELISA and NS1 antigen were used to confirm dengue infection, whereas IgM ELISA was used to confirm chikungunya infection. The Chi-square test was used to statistically analyse data on the total number of samples examined, positivity rates, and co-infection status; p < 0.05 was deemed significant.
Results: During 2024–2025, 3,127 samples were tested for dengue, of which 175 (5.6%) were positive. A total of 2,075 samples were tested for chikungunya, among which 192 (9.3%) were positive, while 26 patients showed co-infection. During 2025–2026, 3,760 dengue samples were tested and 103 (2.7%) were positive. Among 1,969 chikungunya samples, 119 (6.0%) were positive, and 16 cases demonstrated co-infection. Overall, the study identified 42 co-infected patients. Chikungunya positivity was significantly associated with dengue positivity (p < 0.05). A declining trend in dengue positivity was observed in the second year, whereas chikungunya prevalence remained comparatively high.
Conclusion: Dengue–chikungunya co-infection constitutes a significant public health concern in western Uttar Pradesh. Simultaneous testing for both arboviral infections should be encouraged in endemic regions to facilitate early diagnosis, appropriate management, and improved surveillance strategies.