RESUMO
OBJECTIVE: The objective of this survey was to describe epidemiological characteristics and evaluate vaccine effectiveness against pertussis in the sub-prefecture of Baoro (Central African Republic). METHOD: We conducted a case control study from June to July 2022 in the sub-prefecture of Baoro in the district of Baour-Baoro. Community-based definitions of surveillance were applied to include cases and controls. RESULTS: All in all, 143 confirmed and suspected cases and 166 controls were enrolled in this investigation. The epidemic had affected 12 neighborhoods and 9 villages. The village of Bugbassem alone had 32 patients, and 50% of the patients lived in rural areas. The age groups of 12 to 59 months accounted for 58% of cases. Patients were female in 54% of cases (p = 0.8). The attack rate among unvaccinated patients (65%) was higher than that of vaccinated patients (40%), while 15% (N = 21) of children were hospitalized with no recorded deaths. Pentavalent 3rd dose vaccination coverage was 49% in controls versus 33% in cases. Vaccination provided a significant protective effect (Odds Ratio = 0.3; 95% CI: 0.2-0.6). All told, vaccine efficacy against pertussis was 38%. CONCLUSION: Pertussis is a re-emerging disease currently occurring as a result of low pertussis vaccination coverage. It strongly affects rural areas with low vaccination rates. Vaccination strategy requires reinforcement in rural areas.
