New Reassortant H5N6 Highly Pathogenic Avian Influenza Viruses in Southern China, 2014

Abstract

New reassortant H5N6 highly pathogenic avian influenza viruses (AIVs) were isolated from apparently healthy domestic ducks in Southern China in 2014. Our results show that the viruses grew efficiently in eggs and replicated systemically in chickens. They were completely lethal in chicken (100% mortality), and the mean death time was 6 to 7 days post-inoculation. The viruses could transmit in chickens by naïve contact. BLAST analysis revealed that their HA gene was most closely related to A/wild duck/Shangdong/628/2011 (H5N1), and their NA genes were most closely related to A/swine/Guangdong/K6/2010 (H6N6). The other genes had the highest identity with A/wild duck/Fujian/1/2011(H5N1). The results of phylogenetic analysis showed that their HA genes clustered into clade 2.3.4.4 of the H5N1 viruses and all genes derived from H5 were Mix-like or H6-like viruses. Thus, the new H5N6 viruses were reassortmented of H5N1 and H6N6 virus. Therefore, the circulation of the new H5N6 AIVs may become a threat to poultry and human health.

Genesis and Dissemination of Highly Pathogenic H5N6 Avian Influenza Viruses

“…It is important to understand the origins and genesis of these subtype viruses and to determine their relationships with other subtype viruses in this clade. Previous studies revealed that the HPAI H5N6 virus contained the hemagglutinin (HA) gene of H5 clade 2.3.4.4, the internal genes of H5 clade 2.3.2.1, and the NA gene from the H6N6 avian virus (9,12,13). Based on the genetic evidence, HPAI H5N6 virus likely originated from migratory waterfowl (14).…”

Avian influenza overview September – November 2017

“…However, virus isolation from apparently healthy ducks and geese in live bird markets in China was also described (Jiao et al, 2016;Sun et al, 2016). Increased mortality in galliforms as well as increased mortality and neurological signs (torticollis, ataxia) in domestic ducks were reported from the Republic of Korea (OIE reports).…”

“…Increased mortality in galliforms as well as increased mortality and neurological signs (torticollis, ataxia) in domestic ducks were reported from the Republic of Korea (OIE reports). However, virus isolation from apparently healthy ducks and geese in live bird markets in China was also described (Jiao et al, 2016;Sun et al, 2016). A Korean A(H5N6) isolate was tested in 6-week-old SPF chickens inoculated intravenously and the IVPI value was 2.66 .…”

“…Experimental infection of 6-week-old chickens infected via the intranasal route (10 6 EID 50 ) with A(H5N6) HPAIV isolated from apparently healthy ducks in Southern China resulted in the quick progression of clinical signs, including depression, anorexia, and death of 100% birds within 6-7 days post infection. The virus replicated in a wide range of organs and was successfully transmitted to naïve chickens that also died (Jiao et al, 2016).…”

Community-acquired Pneumonia: A Global Perspective

“…So far human cases have been constrained to South-East and Eastern Asia but concerns remain about the potential for a virulent human pandemic due to continued mutation of these viruses. 54 All these new pathogens draw attention to the fact that we are a global community and problems in one country can quickly become problems worldwide. Continual erosion of natural habitats and increasing numbers of humans living in closer proximity to zoonotic hosts make further epidemics of novel viruses inevitable and given how quickly they can spread with modern global transport.…”