Epidemiological, clinical, and virological profile of influenza in the Democratic Republic of the Congo, from 2009 to 2018

Introduction: since 2007, the Democratic Republic of the Congo has implemented a sentinel influenza surveillance systems, operating across 11 healthcare facilities. These facilities collected oropharyngeal and nasopharyngeal samples from patients suspected of having influenza, based on case definitions. The collected samples were then sent to the national influenza laboratory at the INRB for analysis. This study describes the epidemiological, clinical, and virological profiles of these patients. Methods: we conducted a crosssectional study based on a documentary review of notification forms of suspected influenza cases, from January 2009 to December 2018. The variables analyzed included sex, age, symptoms, sentinel site, patient category, identified viral type and subtype, and the period occurrence. Results: out of a total of 18,461 reported cases, 1,795 (9.7%) tested positive for the Influenza virus. Children under five years old accounted for 53.1% of positive cases. Influenza type A was present in 68% of cases, while type B accounted for 31.5%. Positive SARI (Severe Acute Respiratory Infection) cases represented 21%, whereas positive ILI (Influenza-Like Illness) cases accounted for 79%. The vast majority of cases occurred during the rainy season. Conclusion: this study enabled us to determine the burden of influenza among acute respiratory infections and the prevalence of circulating influenza viruses.