The National Burden of Influenza-Associated Respiratory Illness Across Levels of Severity in Egypt, 2016-2019.

INTRODUCTION

Influenza burden (IB) estimates are crucial for monitoring disease trends, allocating limited resources, and promoting influenza vaccination. However, IB in Egypt is poorly understood. This study estimates the mean-seasonal IB in Egypt, across levels of severity by age and regions using sentinel surveillance data between 2016 and 2019.

METHODS

Influenza surveillance was implemented among patients hospitalized with severe acute respiratory infection (SARI) at eight sentinel hospitals across Egypt. We estimated the influenza-associated SARI hospitalization in two governorates and then extrapolated nationally using the World Health Organization (WHO)-recommended methods. Thereafter, we estimated IB-associated mild/moderate illness and deaths using IB pyramid tool developed by WHO and the John Hopkins Center for Health Security. Rates were reported per 100,000 population.

RESULTS

The estimated mean seasonal number of influenza-associated mild/moderate illness, hospitalized noncritically and critically ill patients, and deaths was 16,425,938 (95% CI: 1,150,888-40,409,614), 30,335 (95% CI: 9971-670,288), 9110 (95% CI: 580-16,321), and 2660 (95% CI: 154-9908), respectively. The highest rate of influenza-associated mild/moderate illness was among aged 5-14 year (22,932; 95% CI: 825-25,546.3), whereas the highest rates of severe influenza were among aged > 65 years (hospitalizations: 159.4, 95% CI: 121.7-205.0; deaths: 56.0, 95% CI: 0.6-111.0). Children aged < 5 years also experience high rates of influenza-associated hospitalization (52.0, 95% CI: 43.0-62.0).

CONCLUSIONS

The WHO method estimated a high burden of severe influenza among aged ≥ 65 and aged < 5 years in Egypt. To reduce severe IB, increased influenza vaccine uptake together with enhanced immunization strategies implementations among the elderly and children are warranted.