Molecular Detection of Bordetella Species Among Children With Clinically Suspected Pertussis

Background: Pertussis remains an important respiratory infection in children, but clinical diagnosis can be difficult because classic manifestations may be absent or nonspecific. IS481-targeted molecular detection provides high sensitivity but is not completely specific for Bordetella pertussis . This study assessed IS481-positive Bordetella DNA among children with clinically suspected pertussis and compared conventional culture with real-time PCR. Methods: This prospective observational study included 95 children aged 3 months to 12 years with clinically suspected pertussis, enrolled between May 2021 and May 2022. Nasopharyngeal specimens were tested by conventional culture and IS481-targeted real-time PCR. Associations between IS481 positivity and demographic, clinical, and vaccination characteristics were assessed using Fisher exact test. Results: IS481-positive Bordetella DNA was detected in 7/95 children (7.4%), whereas culture identified 1 Bordetella pertussis isolate (1.1%). The culture-positive specimen was also PCR-positive, while 6 additional specimens were PCR-positive but culture-negative. Younger age ( P =0.004) and incomplete primary vaccination ( P =0.001) were significantly associated with IS481 positivity. No significant associations were observed with the clinical characteristics evaluated. Conclusions: IS481-positive specimens could not be definitively attributed to B. pertussis without additional species-specific targets. Nevertheless, IS481-targeted real-time PCR detected more Bordetella -positive specimens than culture and may improve laboratory detection among children with suspected pertussis.