Multicenter Study on Children With Bordetella parapertussis Infections

BACKGROUND: Bordetella parapertussis (BPP) causes a pertussis-like illness that is typically milder than classical pertussis, likely due to the absence of pertussis toxin. However, its clinical spectrum remains insufficiently characterized, partly because viral coinfections are frequently present. This study aimed to investigate the clinical course and management of BPP infections in children, specifically excluding cases with coinfections. METHODS: We conducted a multicenter retrospective study of patients aged ≤15 years who underwent multiplex polymerase chain reaction testing using the BioFire Respiratory Panel 2.1 at 10 hospitals between April 2023 and March 2024. Cases with confirmed BPP detection were included after excluding cases with coinfections. Clinical data, including demographics, presenting symptoms and antimicrobial use, were reviewed. RESULTS: Among 139 patients with BPP, 29 patients were included in the analysis after excluding coinfections. The median age was 3 years. Comorbidities were present in 55.2% of cases, and 21 patients (72.4%) were hospitalized. Common symptoms included cough (n = 21), fever (n = 13), vomiting (n = 4), paroxysm (n = 3) and apnea (n = 1). No cases of inspiratory whoop or cyanosis were observed. Antimicrobial therapy was administered in 18 patients (62.1%). There were no fatalities. CONCLUSION: BPP monoinfection in children presented with a higher frequency of febrile illness compared with classical pertussis. Antibiotics were more frequently prescribed for febrile patients; however, some recovered without antimicrobial treatment. Further studies are warranted to clarify indications for antibiotic use in BPP infection.