Influenza and other respiratory viruses 2018 01 19() doi 10.1111/irv.12539
The importance of influenza viruses in respiratory infections in sub-Saharan Africa has been historically overlooked, including in Burkina Faso. This study therefore aimed at evaluating the prevalence and seasonal occurrence of influenza viruses in children under five years old, at risk of influenza-related complications, presenting with influenza-like illness (ILI) or severe acute respiratory infection (SARI). The study also aimed at identifying the periods with increased influenza transmission for vaccination recommendations in Burkina Faso.
From January 2014 to December 2015, ILI and SARI (2015 only) patients were recruited in six healthcare centers in Burkina Faso. Influenza A and B molecular detection and subtyping was performed. Clade clustering of a subset of A(H1N1)pdm09 and A(H3N2) strains was deduced by performing phylogenetic analyses on hemagglutinin gene sequences. Weekly surveillance data from FluNet (2011-2013; 2016) and this study (2014-2015) were used to identify periods of increased influenza activity.
Influenza A and B viruses were detected in 15.1% (112/743) of ILI and 6.6% (12/181) of SARI patients. Overall, influenza A viruses were largely predominant (81/124, 65.3%), with 69.1% of A(H3N2) and 30.9% of A(H1N1)pdm09 strains. Four waves of increased transmission were identified in 2014-2015, each dominated by different influenza subtypes and clades. Between 2011 and 2016, periods of increased influenza activity varied in their frequency, duration and timing.
Influenza A and B viruses were detected in a substantial number of ILI and SARI cases in Burkina Faso. Vaccination in September-October would likely protect the highest number of patients. This article is protected by copyright. All rights reserved.