Analysis of Trends in Dengue Infection among Patients Attending a Tertiary Care Teaching Hospital: A Retrospective Observational Study

Abstract

Introduction: Dengue, a common mosquito-borne arboviral infection in tropical countries, presents cyclical epidemics and seasonal variations with diverse clinical outcomes. Over the past three decades, it has become endemic in India, leading to a rising mortality trend, primarily due to its severity and antibody-dependent enhancement in secondary dengue cases. Therefore, understanding the trend of dengue infection in specific geographical areas is crucial for more efficient prophylaxis. Aim: To provide a comprehensive overview of the seroprevalence of dengue virus infection in Surat district, including the trends in gender, age distribution, and seasonal variations of dengue infection from 2014 to 2021. Materials and Methods: The present retrospective observational analysis was conducted in the Department of Microbiology, Government Medical College (tertiary care teaching New Civil Hospital), Surat, Gujarat, India. A total of 31,683 blood samples were received from patients with clinical suspicion of dengue-like illness from January 2014 to December 2021. Data collection took place from March 2022 to May 2022, and the analysis was conducted in June and July 2022. All samples underwent dengue infection detection using the Enzyme-linked Immunosorbent Assay (ELISA) method by Non structural 1 (NS1) antigen detection and Immunoglobulin M (IgM) antibody detection by Mac capture ELISA. Demographic and clinical details were obtained and recorded from laboratory request forms using a structured data sheet in using Microsoft Excel software version 2013. The data were entered and analysed using EpiInfo software version 3.5.1. Results: Among the 31,683 blood samples tested, 5,994 (18.91%) cases were confirmed for dengue infection through ELISA testing. The highest number of positive cases (33.6%) was observed in the 20-29 years age group, with males outnumbering females in terms of dengue positivity at a ratio of 1.37:1. The maximum number of dengue cases occurred during the postmonsoon and early winter periods, with 96.5% of cases reported from Surat district, India. Conclusion: The rising trend of dengue infection in different age groups over the years underscores the need for continued implementation of surveillance and preventive strategies before the monsoon, aiming to reduce severe dengue infections in the future.