Epidemiological, Clinical and Virological Profiles of Influenza Infection in the Democratic Republic of the Congo, from 2009 to 2018

Background: To better understand the epidemiological characteristic of influenza infection, the Democratic Republic of Congo set up the sentinel influenza surveillance system in 2007 with eleven health facilities. Oral and nasopharyngeal specimens were sampled from outpatients with influenza-like illness (ILI) and inpatients with severe acute respiratory illness (SARI) using case definitions. Those specimens were shipped to the Influenza National Laboratory for testing with the real-time reverse-transcription polymerase chain reaction. This study aimed to describe ILI and SARI patients’ epidemiological, clinical, and virological profiles. Material and Method: We conducted a cross-sectional study based on a documentary review of suspected notified influenza cases from January 2009 to December 2018. As variables, we exploited sex, age, symptoms, sentinel site of provenance, patient category, viral type and subtype identified, and period of health facility visit. Results: Of 18,461 notified cases, 1795 (9.7%) were positive for the Influenza virus, among them; 53.1% of patients under five years old; 68% of type A virus, 31.5% of type B; 21% of SARI positive vs. 79% for ILI positive cases. The majority of cases occurred during the rainy season. Conclusion: The results of this study contribute to a better understanding of the influenza infection in the Democratic Republic of Congo.