Epidemiological investigation of a pertussis outbreak among schoolchildren in Burkina Faso, 2019

Introduction: Pertussis remains among the top ten most common fatal aetiologies of acute respiratory infections worldwide. This study reports findings from the first laboratory-confirmed pertussis outbreak among primary schoolchildren in Burkina Faso.

Methods: A cross-sectional study was conducted during an outbreak in the districts of Sabou and Sapouy following an alert from the national surveillance system. Suspected pertussis cases were investigated, with oropharyngeal/nasopharyngeal samples and sociodemographic and clinical data collected. Samples were analyzed using multiplex rRT-PCR and the FTD-33 Kit (Fast Track Diagnostics, Luxembourg). Descriptive statistics were conducted, and factors associated with pertussis positive cases were assessed using the Chi-square test and univariate logistic regression.

Results: A total of 92 suspected pertussis cases with no fatal outcomes were identified among the schoolchildren in two different clusters during the investigation. The overall attack rate of the two clusters were 18.4% (92/499). Fifteen (16.6%) cases were biologically confirmed. The average age was 8.9 years, and 62% (57/92) were female. Rhinovirus (17.3%) and adenovirus (7.6%) were the most prevalent respiratory viruses detected among the suspected cases. Streptococcus pneumoniae (58.7%) and Haemophilus influenzae (56.5%) were the most common bacteria detected. A significant association was found between sore throat and confirmed cases (OR = 3.5, CI 95% [1.01–11.9]).

Conclusion: Despite extensive vaccination in several countries, pertussis can still cause outbreaks. Preventive measures, such as booster vaccinations for children outside the Expanded Program of Immunization (EPI) target age, are necessary.