Bordetella pertussis re-emergence - NGS-based RPTM analysis reveals the atypical clinical features of children

Abstract Background Bordetella pertussis (BP) infection has risen rapidly in pediatrics recently, and next-generation sequencing has significantly improved pertussis’ early diagnosis. High detection rates raise the concern of pertussis re-emergence. We used tNGS to analyze respiratory secretions from children with lower respiratory tract infections, aiming to assess the significance of BP co-detected. Methods This study included pediatric patients aged 1 month to 14 years who were hospitalized for lower respiratory tract infections from April 2023 to March 2024. Respiratory secretions were collected and analyzed using tNGS sequencing. Clinical data were collected, including clinical symptoms and laboratory markers. According to tNGS read per ten million (RPTM), pertussis patients were divided into three groups: low RPTM group (< 10,000), medium RPTM group (10,000–25,000), and high RPTM group (> 25,000). The association between pertussis RPTM and clinical characteristics was evaluated. Results Among the 865 pediatric lower respiratory tract infections, 56 cases (6.47%) were tested BP positive in respiratory secretions using tNGS. Bordetella pertussis primarily affected children over 4 years old and lacked typical clinical symptoms and laboratory markers. All patients with BP infection were co-detected with other common pathogens. The high RPTM group was more common in children under 4 years old, in which pertussis appeared as the predominant pathogen, with a shorter fever duration and lower lung consolidation/pulmonary atelectasis incidence. In contrast, the low-RPTM group was more common in elder children, with prolonged fever, co-infection with mycoplasma pneumoniae, and lung parenchymal lesions. Conclusion Pertussis re-emergence primarily happens to older children who present with atypical clinical features and are co-infected. tNGS RPTM analysis helped identify the dominant pathogen in pertussis infections. Clinical trial number Not applicable.