High pertussis circulation among infants, children and adolescents in Abidjan, Côte d'Ivoire.

Abstract

BackgroundWhooping cough due to Bordetella pertussis (BP) and/or B. parapertussis (BPP) is a highly contagious infection sometimes fatal for infants. Africa accounts for the largest share of cases and deaths worldwide. To evaluate pertussis circulation, we conducted a hospital-based prospective study (PS) including household contact-cases investigation (CCS) and a sero-epidemiological cross-sectional study (SECS).MethodsThe PS, in which Bordetella diagnostics (qPCR) were performed, included infants aged ≤6 months presenting with ≥5 days of cough associated with one pertussis-like symptom. CCS was performed using qPCR and serology regardless of clinical signs. In the SECS, serology was performed in children aged 3-15 years with primary pertussis immunization.ResultsStudy took place in Abidjan between April 2019 and July 2021. In the PS, 187 infants with median age of 2.8 months were enrolled. A total of 42 (22.5%) were confirmed as positive, including 29 (15.5%), 4 (2.1%) and 9 (4.8%) of BP, BPP and BP/BPP coinfections respectively. Age ConclusionOur study highlighted high circulation of pertussis. Barriers to accessing boosters recommended by WHO need to be overcome. Laboratory capacities are key at individual level and to build an effective surveillance system.