Isolation of a Novel Reassortant Highly Pathogenic Avian Influenza (H5N2) Virus in Egypt

Abstract

Highly pathogenic avian influenza (HPAI) H5N1 and H5N8 have become endemic among domestic poultry in Egypt since 2006 and 2016, respectively. In parallel, the low pathogenic avian influenza H9N2 virus has been endemic since 2010. Despite the continuous circulation of these subtypes for several years, no natural reassortant has been detected so far among the domestic poultry population in Egypt. In this study, the HPAI (H5N2) virus was isolated from a commercial duck farm, giving evidence of the emergence of the first natural reassortment event in domestic poultry in Egypt. The virus was derived as a result of genetic reassortment between avian influenza viruses of H5N8 and H9N2 subtypes circulating in Egypt. The exchange of the neuraminidase segment and high number of acquired mutations might be associated with an alteration in the biological propensities of this virus.

H5 Influenza Viruses in Egypt

“…Although no A(H5N1)/A(H9N2) reassortants have been described, a novel A(H5N8)/A(H5N1) reassortant has been detected in a duck. This virus contained seven A(H5N8) virus genes with the N2 from the A(H9N2) virus (Hagag et al 2019). The complete significance of this or similar viruses remains unknown.…”

“…In the second event, there was another introduction(s) of Gs/GD A(H5) viruses from Asia, this time of clade 2.3.4.4 A(H5N8) viruses Salaheldin et al 2018a). These viruses have slowly displaced clade 2.2 viruses and have not been detected in humans, but reassortment with circulating A(H9N2) viruses has been observed (Hagag et al 2019) (see below for more details).…”

Avian influenza overview February– August 2019

“…Furthermore, the Asian lineage HPAI A(H5N2) was for the first time detected in wild birds; a grey heron (Ardea cinerea) found dead in Guandu Park in Taipei City. The (Hagag et al, 2019). Phylogenetic analysis showed that the virus had emerged as a result of reassortment between A(H5N8) clade 2.3.4.4B and A(H9N2) viruses of the G1 lineage, endemically circulating in the country since 2011.…”

First detection of highly pathogenic H5N6 avian influenza virus on the African continent

“…comm.) in the country may represent a diagnostic challenge, considering that new reassortant viruses could emerge, as recently reported in Egypt [13,14], and spread. Urgent actions to strengthen surveillance efforts, combined with eradication measures, adequate compensations and education of farmers are needed to contain and monitor virus spread and the emergence of novel viruses of animal and public health concern.…”