Pertussis: a retrospective analysis of cases observed in Mersin Türkiye, 2020 to 2024 evaluation of pertussis cases.

BACKGROUND

Whooping cough is endemic in many regions in Türkiye and the world, and is an important cause of morbidity and mortality, especially in children and adolescents. The aim of this study was to evaluate the epidemiological findings of pertussis cases in a region.

METHODS

The cross-sectional study was conducted in 2024-2025. The study evaluated the relationship between the frequency of pertussis cases reported in 2020 to 2024 and the demographic characteristics of the patients (age, gender, nationality, district of residence, etc.), the season of notification, and vaccination status. The definitive diagnosis of the cases was made by isolating Bordotella pertussis from nasopharyngeal sample cultures or by detecting the Bordotella pertussis gene in nasopharyngeal samples by PCR.

RESULTS

When the distribution of cases in Mersin province by years was examined, 2 cases were detected in 2020, 1 in 2021, 0 in 2022, 3 in 2023, and 92 cases in 2024. It was determined that there was a significant increase in the number of cases in 2024 compared to previous years. Of the 92 cases reported in 2024, 46 were laboratory confirmed and the case rate in 2024 was determined as 2.35 per hundred thousand. 57 cases (62.0%) had never been vaccinated with pertussis vaccine. Of the 46 cases with positive results, 30 (65.2%) were unvaccinated and 42 (91.3%) were younger than 6 months. The frequency of case positivity was significantly higher in infants younger than 6 months (p=.028).

CONCLUSIONS

The increase in cases in 2024 is thought to be linked to migration movements.Protective measures, especially vaccination studies, should be increased in infants younger than 6 months and pregnants where the frequency of cases is high.

CLINICAL TRIAL NUMBER: Not applicable.