Incidence of influenza virus-associated severe acute respiratory infection in Damanhour district, Egypt, 2013.

The epidemiology, seasonality and risk factors for influenza virus infection remains poorly defined in countries such as Egypt. Between 1 January and 31 December 2013, we used surveillance data on patients hospitalized with severe acute respiratory infection in three Egyptian government hospitals in Damanhour district to estimate the incidence rate of laboratory-confirmed seasonal influenza. Samples were taken from 1727 of 1856 patients; of these, 19% were influenza virus positive. The overall incidence of influenza virus-associated SARI during the study period was estimated to be 44 cases per 100 000 person-years (95% CI: 39-48). The highest incidence of 166 cases per 100 000 person year (95% CI: 125-220) was observed in children aged 2 to 4 years. The incidence of influenza-virus associated SARI cases in pregnant women was estimated to be 17.3 cases per 100 000 person-years (95% CI: 6-54). Majority of influenza virus-associated SARI occurred in autumn and early winter, and influenza A(H3N2) virus predominated. This was the first ever description of the epidemiology of seasonal influenza in Egypt. However, additional works are needed for greater understanding of influenza burden in Egypt.