Bordetella Pertussis in Children: A Retrospective Analysis of the Clinical Impact and the Role of Vaccination.

Pertussis, a highly contagious disease, contributes to a great number of hospitalizations among children, with an increased risk of morbidity and mortality. The aim of the study was to investigate the epidemiological and clinical features of B. pertussis infections among hospitalized children and to compare the clinical course according to vaccination status and the presence of co-infections. We performed a retrospective study, which included patients positive for B. pertussis detected by multiplex RT-PCR panels, from September 2022 to May 2025. Out of 2493 samples, 84 tested positive for B. pertussis (3.37%). Age-appropriate immunization was achieved in 19.1% (16/84) cases, 10.7% (9/84) were incompletely vaccinated, 9.5% (8/84) did not meet the age criteria and 60.7% (51/84) were not vaccinated. Infants ≤ 3 months were more susceptible to mixed co-infections (52%), had a more severe course, with transfers to the ICU (32%) and a prolonged average length of stay (9.2 days). Co-infections were found in 39.3% cases, rhinovirus being the most common agent (17.9%). B. pertussis and rhinovirus co-infection was associated with a decreased SpO2 level (<92%) and increased CRP and Ferritin levels.