Preliminary epidemiological and clinical profile of the 2024 pediatric pertussis outbreak: a retrospective analysis

Background In 2024, a global surge in pediatric pertussis cases emerged, deviating from traditional clinical patterns. This outbreak was characterized by atypical symptoms and increased hospitalization rates. This study aimed to characterize the epidemiological and clinical features of children hospitalised with pertussis during the outbreak in the Fuzhou region of China and to identify predictors of prolonged hospitalization. Methods We performed a retrospective analysis of PCR-confirmed pediatric pertussis cases admitted to Fuzhou Second General Hospital in 2024. We evaluated demographics, clinical signs, lab results, and treatment. Univariable and multivariable linear regression analyses were performed to identify factors associated with hospitalization duration. Additional LASSO regression analysis was performed as a sensitivity analysis. Results A total of 69 children with PCR-confirmed pertussis were included in the analysis. In 2024, the pertussis outbreak began in April, peaked in June-July, and declined by August. Infants and preschool-aged children bore the highest disease burden, with a notable incidence in school-aged children. Unexpectedly, prolonged hospitalization correlated with the absence of fever and normal inflammatory markers. Multivariate analysis identified elevated platelet counts ( β = 0.008, p = 0.003) and increased alanine aminotransferase (ALT) levels ( β = 0.038, p = 0.018) as key predictors of extended hospital stays, offering new insights for clinical risk assessment. Conclusions In this retrospective study of children hospitalised with pertussis during the 2024 Fuzhou outbreak, infants and school-aged children were disproportionately affected, with a seasonal distribution. Prolonged hospital stays were linked to afebrile presentations with normal inflammatory markers, while elevated platelet counts and ALT levels may predict extended hospitalization. These findings may offer useful reference points for clinical risk stratification, though validation in larger multicenter prospective studies is warranted.