Prevalence and changing trend of dengue in a tertiary care hospital in southeastern Rajasthan

Abstract

Background: Dengue fever, an endemic mosquito-borne illness in Rajasthan, India, has shown a rising incidence and seasonal pattern in recent years. Its clinical spectrum ranges from mild self-limiting illness to severe manifestations such as dengue hemorrhagic fever and shock syndrome. In India, the disease has spread widely over the past two decades, now affecting nearly all regions, including the Hadoti area of Rajasthan. Objective: To determine dengue seropositivity by NS1 antigen and anti- dengue IgM antibody detection through ELISA, and to correlate the results with evolving epidemiological trends. Materials and methods: A cross-sectional study was conducted from November 2021 to April 2024, with blood samples tested from clinically suspected cases of dengue virus infection. Results: Between November 2021 and April 2024, 652 blood samples were tested (84 in 2021, 184 in 2022, and 92 in 2024). Total number of positive cases was: 55 (65.47%) in 2021 (45 NS1, 24 IgM), 19 (10.32%) in 2022 (4NS1, 17 IgM), 106 (57.06%) in 2023 (95 NS1, 28IgM), and 35 (38.04%) in 2024 (34 NS1, 5 IgM). The age group 15-30 years accounted for the maximum positive cases in all the years: 39 (46.42%) in 2021, 66 (35.86%) in 2022, 114 (39.04%) in 2023, and 29 (31.52%) in 2024. The highest number of cases was observed during the post-monsoon season in rural areas. Conclusion: Prevalence of dengue seropositive cases was 55 (65.47%) in 2021, in 2022, it was 19 (0.10%), in 2023 was 106(57.06%), and in 2024, it was 35(38.04%). indicating a rapid decline in dengue infection, which may be attributable to the collective efforts taken by the healthcare workers and by the people during the timely delivery of preventive and control measures, besides having increased awareness among the people.