Morbidity, Mortality, and Seasonality of Influenza Hospitalizations in Egypt, November 2007-November 2014

BACKGROUND Influenza typically comprises a substantial portion of acute respiratory infections, a leading cause of mortality worldwide. However, influenza epidemiology data are lacking in Egypt. We describe seven years of Egypt's influenza hospitalizations from a multi-site influenza surveillance system. METHODS Syndromic case definitions identified individuals with severe acute respiratory infection (SARI) admitted to eight hospitals in Egypt. Standardized demographic and clinical data were collected. Nasopharyngeal and oropharyngeal swabs were tested for influenza using real-time reverse transcription polymerase chain reaction and typed as influenza A or B, and influenza A specimens subtyped. RESULTS From November 2007-November 2014, 2,936/17,441 (17%) SARI cases were influenza-positive. Influenza-positive patients were more likely to be older, female, pregnant, and have chronic condition(s) (all p<0.05). Among them, 53 (2%) died, and death was associated with older age, five or more days from symptom onset to hospitalization, chronic condition(s), and influenza A (all p<0.05). An annual seasonal influenza pattern occurred from July-June. Each season, the proportion of the season's influenza-positive cases peaked during November-May (19-41%). CONCLUSIONS In Egypt, influenza causes considerable morbidity and mortality and influenza SARI hospitalization patterns mirror those of the Northern Hemisphere. Additional assessment of influenza epidemiology in Egypt may better guide disease control activities and vaccine policy.