Surveillance on A/H5N1 virus in domestic poultry and wild birds in Egypt

Abstract

BackgroundThe endemic H5N1 high pathogenicity avian influenza virus (A/H5N1) in poultry in Egypt continues to cause heavy losses in poultry and poses a significant threat to human health.MethodsHere we describe results of A/H5N1 surveillance in domestic poultry in 2009 and wild birds in 2009–2010. Tracheal and cloacal swabs were collected from domestic poultry from 22024 commercial farms, 1435 backyards and 944 live bird markets (LBMs) as well as from 1297 wild birds representing 28 different types of migratory birds. Viral RNA was extracted from a mix of tracheal and cloacal swabs media. Matrix gene of avian influenza type A virus was detected using specific real-time reverse-transcription polymerase chain reaction (RT-qPCR) and positive samples were tested by RT-qPCR for simultaneous detection of the H5 and N1 genes.ResultsIn this surveillance, A/H5N1 was detected from 0.1% (n = 23/) of examined commercial poultry farms, 10.5% (n = 151) of backyard birds and 11.4% (n = 108) of LBMs but no wild bird tested positive for A/H5N1. The virus was detected from domestic poultry year-round with higher incidence in the warmer months of summer and spring particularly in backyard birds. Outbreaks were recorded mostly in Lower Egypt where 95.7% (n = 22), 68.9% (n = 104) and 52.8% (n = 57) of positive commercial farms, backyards and LBMs were detected, respectively. Higher prevalence (56%, n = 85) was reported in backyards that had mixed chickens and waterfowl together in the same vicinity and LBMs that had waterfowl (76%, n = 82).ConclusionOur findings indicated broad circulation of the endemic A/H5N1 among poultry in 2009 in Egypt. In addition, the epidemiology of A/H5N1 has changed over time with outbreaks occurring in the warmer months of the year. Backyard waterfowl may play a role as a reservoir and/or source of A/H5N1 particularly in LBMs. The virus has been established in poultry in the Nile Delta where major metropolitan areas, dense human population and poultry stocks are concentrated. Continuous surveillance, tracing the source of live birds in the markets and integration of multifaceted strategies and global collaboration are needed to control the spread of the virus in Egypt.

Epidemiology, ecology and gene pool of influenza A virus in Egypt: Will Egypt be the epicentre of the next influenza pandemic?

“…41 A similar observation was reported by ElZoghby et al 34 who isolated 2 viruses from 2 adjacent poultry farms but belonging to 2 different genetic lineages whereas 2 viruses from LBM and commercial farms from 2 different provinces (about 800 km apart) clustered together. Another critical aspect in the epidemiology of H5N1 is LBM where the virus has been detected year-round.…”

“…33 Since then, outbreaks have been reported nationwide and the disease is now concentrated in the Nile Delta region where high-density human and poultry populations exist. 33,34 As of the end of 2011, approximately most of the domesticated birds have been infected with the virus including chickens, ducks, geese, turkeys, quails, and ostrich as well as zoo birds 30,35,36 and evidence for the persistence of the virus in native-ducks in the backyards in mid-summer 2011 was reported. 37 In the first outbreak in 2006 we could not detect the virus from pigeons, 30 however in 2009-2010 the viral RNA was detected in one pigeon and in 2010-2012 in 36 samples.…”

“…Therefore, attention has been paid to the possible role of wild birds in the introduction of different pathogens including IAV. 29,34,[74][75][76][77][78][79] While a considerable number of IAV subtypes have been isolated from wild birds in Egypt through several collaborative research projects ( 78 Interestingly, it was found that viruses originated from 4 different flyways rather than the 2 flyways in Egypt. 78 The most infected wild birds in Egypt were the northern shoveler, common teal and Egyptian goose ( 39 and from a common teal (Anas crecca) in October 2005.…”

Surveillance on Avian Influenza H5N1 and H9N2 Subtypes In Egypt 2012-2013

“…While El-Zoghby et al [23] recorded only 23 positive farms out of 22024 totals examined farm giving 0.1% in 2009 (Figure 2). Surprisingly, in late 2009-2010, seventy different chicken flocks showed high mortality rates with respiratory manifestation examined for avian influenza infection and 31 farms (40%) were positive for avian influenza virus infection [19,12] indicating high rate of infection in the studied farms.…”

“…Therefore, the permanent and updated surveillance programs as early warning measure should be taken for prompt diagnosis of avian influenza infections and to allow the implementation of restriction, eradication and vaccination policies and to help in developing new control strategies [23,[30][31][32][33][34]. …”