[Trends in the epidemiology of pertussis in Malaga, Spain (2017-2024)].

Background: Description of the epidemiological evolution of pertussis in the province of Malaga, Spain (2017 - 2024), disease severity, and vaccination coverage.

Methods: A cross-sectional study was conducted using reported cases from the Andalusian Notifiable Diseases Network (RedAlerta). The incidence of pertussis was calculated per 100,000 inhabitants for each health district, quarter, and year. Additionally, the relationship between severe cases (hospitalizations) and vaccination status was analyzed.

Results: A total of 181 pertussis cases were identified. Of these, 56.4% were reported during the pre-pandemic period (2017-2019), while 9.95% occurred between 2020 and 2023. An increase in cases was observed in the first quarter of 2024 (n = 61; 33.7% of the total cases), compared to previous years (1 to 46 cases). The 0 to 20-year group accounted for 71.3% of cases, of which 57.4% had received at least partial vaccination prior to contracting pertussis. Severe disease requiring hospitalization occurred in 25.6% of cases, with a higher frequently among unvaccinated individuals (70% vs 18.3%; p < 0.001). Among hospitalized cases, 42.4% had not received any prior doses of the vaccine. Additionally, 47.1% of the 17 pertussis cases in children aged =1 year had not received any vaccination and had no history of maternal vaccination during pregnancy.

Conclusions: An increase in reported pertussis cases is observed in early 2024 in Malaga, but hospitalization rates among confirmed cases remained stable. A significant association is found between prior vaccination against pertussis and reduced disease severity (hospitalization) in the 0 to 20-year-old age group.