The evolution of dengue fever trends in the Central-West Region of Brazil: an 11-year analysis of incidence data from 2013 to 2023 in Mato Grosso do Sul.

Background: In 2024, Dourados, Mato Grosso do Sul, Brazil became the first municipality to launch a mass dengue vaccination campaign in individuals aged 4-60 years of age. We describe the historical incidence of dengue in Dourados and the municipality of Ponta Porã, Mato Grosso do Sul where vaccination was limited to individuals aged 10-14 years as part of a vaccination campaign initiated in Feb 2024.

Methods: This descriptive, retrospective, epidemiological study used aggregated dengue data from the Brazilian Notifiable Diseases Information System collected from January 2013 to December 2023 for individuals aged 4-60 years from Dourados and Ponta Porã. Annual incidence of suspected and confirmed dengue cases was expressed as cases per 100,000 population and stratified by sex, age, and calendar month.

Results: 19,349 suspected and 11,439 confirmed dengue cases were reported in Dourados and 13,260 suspected and 6861 confirmed dengue cases in Ponta Porã. The 4-17 years age group had lowest incidence rates (confirmed: Dourados=217/100,000, Ponta Porã=295/100,000), with higher incidence rates in the 18-45 years age group (confirmed: Dourados=681/100,000, Ponta Porã=1089/100,000). There was a reduced relative risk of dengue for the 4-17 versus 18-45 age group (IRR =0.27-0.32). Peak incidence rates occurred in March-April, with lowest rates in August-October.

Conclusions: Dengue is a public health challenge in Mato Grosso do Sul. Preventive interventions are crucial to alleviate disease burden and control outbreaks.