Isolation and identification of highly pathogenic avian influenza H5N1 virus from Houbara bustards (Chlamydotis undulata macqueenii) and contact falcons

Abstract

Highly pathogenic influenza virus (HPAIV) H5N1 has caused mortality and morbidity in many species of domestic and wild bird. The Houbara bustard (Chlamydotis undulata macqueenii) is a solitary bird that inhabits semi-desert regions. It is known to be susceptible to avianpox, avian paramyxovirus type 1, and low-pathogenicity avian influenza H9N2. We report an outbreak of H5N1 HPAIV in Houbara bustards, which were introduced into the Kingdom of Saudi Arabia for falconry purposes. Ninety-three per cent mortality (38 out of 41 birds) in the infected Houbara bustard flock and about 62.5% mortality (10 out of 16 birds) in falcons that came in contact with these birds were observed. Pooled cloacal and tracheal swabs from Houbara bustards as well as visceral organ homogenates collected in Houbara bustards and falcons were tested by real-time reverse transcriptase-polymerase chain reaction, and virus isolation was attempted in specific pathogen free hens' eggs. The viruses isolated were characterized as HPAIV H5N1. Phylogenetic analysis of the haemagglutinating and Neuraminidase (NA) genes revealed that the viruses isolated from Houbara bustards and falcons were closely related to each other and to Kuwaiti H5N1 strains isolated in 2007. Interestingly, they were genetically distinguishable from the co-circulating A/H5N1 viruses in Kingdom of Saudi Arabia causing outbreaks in domestic birds. This case emphasizes the need for surveillance of this endangered species in its natural habitat.

Outbreaks of highly pathogenic avian influenza H5N1 clade 2.3.2.1c in hunting falcons and kept wild birds in Dubai implicate intercontinental virus spread

“…A previous outbreak in Saudi Arabia and Kuwait was caused by H5N1 viruses of clade 2.2 (Khan et al, 2009;Marjuki et al, 2009). The current scenario affecting the UAE appears to be similar in the extent of affected species and the epidemiological patterns, but the HPAIVs causing the outbreak are grouped into clade 2.3.2.1c.…”

“…Outbreaks of HPAIV H5N1 or other avian influenza viruses involving falcons reared for hunting and several species of kept wild birds bred as falcon prey are not without precedent in the Arabian Peninsula (Aamir et al, 2007;Khan et al, 2009;Marjuki et al, 2009;Wernery et al, 2013). A previous outbreak in Saudi Arabia and Kuwait was caused by H5N1 viruses of clade 2.2 (Khan et al, 2009;Marjuki et al, 2009).…”

Victims and Vectors: Highly Pathogenic Avian Influenza H5N1 and the Ecology of Wild Birds

“…Infection with the virus has been recorded in a growing number of bird species in open zoos (Ellis et al, 2004), sanctuaries (Desvaux et al, 2009) and other captive populations (Khan et al, 2009). Captive conditions may provide opportunities for HPAI H5N1 to expand its host range due to the artificially high concentration and assemblage of species.…”

Highly (H5N1) and Low (H7N2) Pathogenic Avian Influenza Virus Infection in Falcons Via Nasochoanal Route and Ingestion of Experimentally Infected Prey

“…However, during recent H5N1 outbreaks, increasing number of birds of prey have been reported to be infected, probably as a result of improvements in sampling and diagnostic tools. It is worth highlighting that Hong Kong had a series of cases of natural infection of peregrine falcons ( Falco peregrinus ) with H5N1 in 2004, 2006 and 2008 [9]–[11], although other countries subsequently reported HPAI cases in different prey species, such as in Hodgson's hawk eagles ( Spizaetus nipalensis ) in Belgium [12], saker falcons ( Falco cherrug ) in Saudi Arabia [13] and, more recently in Saudi Arabia, houbara bustards ( Chlamydotis undulate macqueenii ),which interestingly infected falcons that came into contact with them [14].…”