Sentinel Surveillance Of Influenza In Burkina Faso: Identification Of Circulating Strains During 2010-2012

BackgroundAlthough influenza surveillance has recently been improved in some sub-Saharan African countries, no information is yet available from Burkina Faso.ObjectivesOur study was the first to determine the prevalence of influenza viruses circulating in Burkina Faso through a sentinel surveillance system.MethodsWe conducted sentinel surveillance with oropharyngeal (OP) swabs collected from outpatients (1month to 83years) from six sites in Bobo-Dioulasso and Ouagadougou, among patients meeting the WHO/CDC case definition for influenza-like illness (ILI; fever 38 degrees C, and cough and/or sore throat in the absence of other diagnosis) from July 2010 to May 2012. Influenza viruses were detected by real-time RT-PCR using CDC primers, probes, and protocols.ResultsThe first three ILI cases were enrolled each day; of 881 outpatients with ILI enrolled and sampled, 58 (66%) tested positive for influenza viruses (29 influenza A and 29 influenza B). Among the influenza A viruses, 552% (16/29) were influenza A (H1N1)pdm09 and 448% (13/29) were seasonal A (H3N2). No cases of seasonal A/H1N1 were detected. Patients within 0-5years and 6-14years were the most affected, comprising 414% and 224% laboratory-confirmed influenza cases, respectively. Influenza infections occurred during both the dry, dusty Harmattan months from November to March and the rainy season from June to October with peaks in January and August.ConclusionsThis surveillance was the first confirming the circulation of influenza A (H1N1)pdm09, A/H3N2, and influenza B viruses in humans in Burkina Faso.