Avian influenza virus surveillance in migratory birds in Egypt revealed a novel reassortant H6N2 subtype

Ali M Zanaty,Wessam H Mady,Neveen Rabie,Ahmed A Nour,Ahmed M Erfan,Abdullah A Selim,Mahmoud M Naguib,Mohamed Samy,Fatma Amer,Wafaa M M Hassan

doi:10.1186/s40657-019-0180-7

Abstract

BackgroundAvian influenza viruses (AIVs) have been identified from more than 100 different species of wild birds around the globe. Wild migratory birds can act as potential spreaders for AIVs to domestic birds between different countries. Egypt is situated on important migratory flyways for wild birds between different continents. While much is known about circulation of zoonotic potential H5N1 and H9N2 AIVs in domestic poultry in Egypt, little is known about the pivotal role of migratory birds in the maintenance and transmission of the viruses in Egypt.MethodsTargeted AIV surveillance has been conducted in 2017 in different wetlands areas in Northern and Eastern Egypt.ResultsAIV of subtype H5 was detected in two bird species. In addition, a novel reassortant strain of the H6N2 subtype was identified which reveals the continuous risk of new influenza virus(es) introduction into Egypt. This novel virus possesses a reassortant pattern originating from different AIV gene pools.ConclusionsIntervention control strategies should be performed to minimize the possible contact of domestic birds with wild birds to lower the risk of virus transmission at this interface. In addition, constant monitoring of AIVs in migratory birds is essential in the early detection of influenza virus introduction into Egypt.

Highlights

Avian influenza viruses (AIVs) have been identified from more than 100 different species of wild birds around the globe
Samples were collected from live bird markets (LBMs) near wetlands and lakes in Sharkia, Behira, and Ismailia Governorates in Egypt during a targeted surveillance of wild birds conducted by General Organisation for Veterinary services (GOVs), and more details are presented in Table 1 and Fig. 1
AIV prevalence and host species Seven cloacal and oropharyngeal swabs pools out of the 84 paired cloacal and oropharyngeal swabs pool, collected from migratory birds, were identified as influenza A virus positive according to an analysis of Matrix gene by qRT-PCR

Summary

Introduction

Avian influenza viruses (AIVs) have been identified from more than 100 different species of wild birds around the globe. Wild migratory birds can act as potential spreaders for AIVs to domestic birds between different countries. While much is known about circulation of zoonotic potential H5N1 and H9N2 AIVs in domestic poultry in Egypt, little is known about the pivotal role of migratory birds in the maintenance and transmission of the viruses in Egypt. LPAIVs of the H7 and H9 subtypes are the most frequently detected subtypes in domestic birds, causing considerable economic losses in Zanaty et al Avian Res (2019) 10:41 poultry production (Fusaro et al 2011; Sun and Liu 2015; Thuy et al 2016). The HPAIV infection of domestic birds, in particular of the order Galliformes, is associated with a high mortality rate reaching up to 100%, while HPAIV infections can be asymptomatic in some wild bird species (Pantin-Jackwood and Swayne 2009)

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