Incidence and Seroprevalence of Avian Influenza in a Cohort of Backyard Poultry Growers, Egypt, August 2015-March 2019.

Mokhtar R Gomaa,Samir Refaey,Pamela P Mckenzie,Ahmed Barakat,Richard J Webby,Ahmed Kandeil,Ghazi Kayali,Mona A Elabd,Mohamed A Ali,Mina N Kamel,Amira S El Rifay,Mohamed A Marouf,Eman Elabd,Noura M Abo Shama,Amal Naguib,Dina Abu Zeid

doi:10.3201/eid2609.200266

Abstract

Currently enzootic avian influenza H5N1, H9N2, and H5N8 viruses were introduced into poultry in Egypt in 2006, 2011, and 2016, respectively. Infections with H5N1 and H9N2 were reported among poultry-exposed humans. We followed 2,402 persons from households raising backyard poultry from 5 villages in Egypt during August 2015–March 2019. We collected demographic, exposure, and health condition data and annual serum samples from each participant and obtained swab samples from participants reporting influenza-like illness symptoms. We performed serologic and molecular analyses and detected 4 cases of infection with H5N1 and 3 cases with H9N2. We detected very low seroprevalence of H5N1 antibodies and no H5N8 antibodies among the cohort; up to 11% had H9 antibodies. None of the exposure, health status, or demographic variables were related to being seropositive. Our findings indicate that avian influenza remains a public health risk in Eqypt, but infections may go undetected because of their mild or asymptomatic nature.

Highlights

Enzootic avian influenza H5N1, H9N2, and H5N8 viruses were introduced into poultry in Egypt in 2006, 2011, and 2016, respectively
According to the World Health Organization, the number of confirmed human H5N1 cases in Egypt is 359, of which 120 were fatal [7]. Those cases were detected by public health surveillance when the patients were admitted to hospitals with influenza-like illness (ILI) and had a history of poultry contact [8]
This study demonstrated that the number of cases is underreported and that the casefatality rate is overestimated

Summary

Introduction

Enzootic avian influenza H5N1, H9N2, and H5N8 viruses were introduced into poultry in Egypt in 2006, 2011, and 2016, respectively. According to the World Health Organization, the number of confirmed human H5N1 cases in Egypt is 359, of which 120 were fatal [7] Those cases were detected by public health surveillance when the patients were admitted to hospitals with influenza-like illness (ILI) and had a history of poultry contact [8]. This number is likely an underestimate because many patients might have mild symptoms or be asymptomatic and are less likely to seek medical care and would not be tested or reported. No human cases of H5N8 were reported in Egypt or elsewhere

Methods

Results

Conclusion