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 <i>B. pertussis</i> 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 <i>B. pertussis</i> detected by multiplex RT-PCR panels, from September 2022 to May 2025. Out of 2493 samples, 84 tested positive for <i>B. pertussis</i> (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%). <i>B. pertussis</i> and rhinovirus co-infection was associated with a decreased SpO₂ level (<92%) and increased CRP and Ferritin levels.