Influenza in Africa: Uncovering the Epidemiology of a Long-Overlooked Disease

Influenza is a well-documented cause of morbidity and mortality in high- and middle-income countries. In the past few decades and particularly during the recent influenza pandemic, numerous studies and surveillance reports in the United States, Europe, Australia, and parts of Asia have improved our understanding of the epidemiology and burden of influenza in those regions. In Africa, however, the picture is quite different. Until the latter half of the last decade minimal effort had been made to understand the epidemiology, burden, and seasonality of influenza in Africa, a continent where some of the poorest populations in the world reside; where human immunodeficiency virus (HIV) infection and AIDS, tuberculosis, and malaria have long ravaged residents; and where resources for health are scarce and often directed at securing basic healthcare and prevention measures. As a result, the impact of the disease in this region has been considered negligible [1]. Yet mortality rates due to respiratory disease among children are higher in Africa than anywhere else in the world, and contrary to findings in other regions, the rates remain high [2, 3]. In the past decade, 2 global events have increased concern about influenza in African countries [4, 5]. First, since 2003, outbreaks of infection due to highly pathogenic avian influenza A virus subtype H5N1 have caused human deaths and massive poultry die-offs globally, including in west and north Africa [6]. Second, the 2009 pandemic of influenza A virus subtype H1N1 infection had many countries in Africa scrambling to ramp up surveillance and testing for what at the time was feared to be a devastating new virus.