Characteristics of pertussis in children: A retrospective study of 306 cases in Wuxue, China

We investigated the epidemiological and clinical characteristics of pertussis in children from Wuxue, China, focusing on age-specific patterns in clinical presentation, laboratory findings and outcomes. A retrospective case-control study was conducted on 306 pediatric patients hospitalized with pertussis at Wuxue First People's Hospital between May 2023 and June 2024. Patients were stratified into three age groups: infants (2-12 months, n = 82), preschool children (1-6 years, n = 127), and school-aged children (7-13 years, n = 97). Age-matched healthy controls (n = 306) were included for hematological comparisons. Data were analyzed using SPSS 22.0 and GraphPad Prism 9.5.0. Infants exhibited the most severe clinical profiles, with significantly elevated leukocyte and lymphocyte parameters compared to older groups (P < 0.001). The incidence of pneumonia was the highest in infants (82.93% vs. 33.07% in preschool and 22.68% in school-aged children, P < 0.001). ROC analysis highlighted lymphocyte percentage as a reliable diagnostic marker in infants (AUC = 0.7620). Seasonal peaks occurred in spring (61.44%) and winter (20.91%). Notably, 84.32% of infected children were fully vaccinated, indicating waning immunity. Macrolide-resistant Bordetella pertussis strains were identified in 7.19% of cases however, co-trimoxazole was effective against these resistant strains. Severe pertussis occurred in 14.05% of cases, predominantly in infants (81.40%, P < 0.001). Age is a critical factor in pertussis presentation. The high vaccination rate among cases underscores issues of waning immunity, necessitating updated immunization strategies. Emerging macrolide resistance warrants vigilance, with co-trimoxazole serving as an effective alternative for therapy. Infants require prioritized surveillance and prompt management.