Introduction and enzootic of A/H5N1 in Egypt: Virus evolution, pathogenicity and vaccine efficacy ten years on

Mostafa, Ahmed; Hassan, M. Kabir; Abdel‐Moneim, Ahmed S.; Naguib, Mahmoud M.; Mostafa, Ahmed; Hussein, Islam T. M.; Arafa, Abdel-Satar; Erfan, Ahmed M.; Kilany, Walid H.; Agour, M.G.; El-Kanawati, Z.; Hussein, Heba; Selim, Abdullah; Kholousy, Shereen G; El-Naggar, Heba M.; El-Zoghby, Elham F.; Samy, Ahmed; Iqbal, Munir; Eid, Amal A.M.; Ibraheem, Essam M.; Pleschka, Stephan; Veits, Jutta; Nasef, Soad A.; Beer, Martin; Mettenleiter, Thomas C.; Grund, Christian; Ali, Mohamad; Harder, Timm C.; Hafez, H. M.

doi:10.1016/j.meegid.2016.02.023

Cited by 58 publications

(78 citation statements)

References 106 publications

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“…The likelihood of the importance of these scenarios is low, as the cocirculation of both viruses on the same poultry farms at the same time, the coinfection of chickens with both viruses, and the presence of both viruses in the same poultry field samples have been repeatedly reported (27)(28)(29), However, the emergence and perpetuation of the now extinct HPAIV H5N1 2.2.1.1 clade of vaccine escape mutants from 2008 to 2011 were highly restricted to industrial poultry farms. These viruses did not spill over to backyard holdings, where viruses of another clade (2.2.1.2) prevailed (25). Thus, divergent evolution was fostered even by the sectoral separation of poultry populations in Egypt.…”

Section: Discussionmentioning

confidence: 97%

Natural Reassortants of Potentially Zoonotic Avian Influenza Viruses H5N1 and H9N2 from Egypt Display Distinct Pathogenic Phenotypes in Experimentally Infected Chickens and Ferrets

Naguib

Ulrich

Kasbohm

et al. 2017

J Virol

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The cocirculation of zoonotic highly pathogenic avian influenza virus (HPAIV) of subtype H5N1 and avian influenza virus (AIV) of subtype H9N2 among poultry in Egypt for at least 6 years should render that country a hypothetical hot spot for the emergence of reassortant, phenotypically altered viruses, yet no reassortants have been detected in Egypt. The present investigations proved that reassortants of the Egyptian H5N1 clade 2.2.1.2 virus and H9N2 virus of the G1-B lineage can be generated by coamplification in embryonated chicken eggs. Reassortants were restricted to the H5N1 subtype and acquired between two and all six of the internal segments of the H9N2 virus. Five selected plaque-purified reassortant clones expressed a broad phenotypic spectrum both in vitro and in vivo. Two groups of reassortants were characterized to have retarded growth characteristics in vitro compared to the H5N1 parent virus. One clone provoked reduced mortality in inoculated chickens, although the characteristics of a highly pathogenic phenotype were retained. Enhanced zoonotic properties were not predicted for any of these clones, and this prediction was confirmed by ferret inoculation experiments: neither the H5N1 parent virus nor two selected clones induced severe clinical symptoms or were transmitted to sentinel ferrets by contact. While the emergence of reassortants of Egyptian HPAIV of subtype H5N1 with internal gene segments of cocirculating H9N2 viruses is possible in principle, the spread of such viruses is expected to be governed by their fitness to outcompete the parental viruses in the field. The eventual spread of attenuated phenotypes, however, would negatively impact syndrome surveillance on poultry farms and might foster enzootic virus circulation.IMPORTANCE Despite almost 6 years of the continuous cocirculation of highly pathogenic avian influenza virus H5N1 and avian influenza virus H9N2 in poultry in Egypt, no reassortants of the two subtypes have been reported. Here, the principal compatibility of the two subtypes is shown by forcing the reassortment between copassaged H5N1 und H9N2 viruses in embryonated chicken eggs. The resulting reassortant viruses displayed a wide range of pathogenicity including attenuated phenotypes in chickens, but did not show enhanced zoonotic propensities in the ferret model.

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Section: Discussionmentioning

confidence: 97%

Natural Reassortants of Potentially Zoonotic Avian Influenza Viruses H5N1 and H9N2 from Egypt Display Distinct Pathogenic Phenotypes in Experimentally Infected Chickens and Ferrets

Naguib

Ulrich

Kasbohm

et al. 2017

J Virol

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“…Since 2006, the highly pathogenic avian influenza H5N1 virus has circulated among domestic poultry in Egypt, causing massive economic losses in the poultry production sector (1). Within a few months of the first wave of H5N1 virus in 2006, the veterinary authorities in Egypt implemented a comprehensive response plan to control the spread of the virus in Egypt; this included increasing public awareness through the media, culling infected poultry, placing restrictions on the movement of live poultry, and applying biosecurity measures and emergency vaccination (2,3).…”

Section: Introductionmentioning

confidence: 99%

Active surveillance of avian influenza viruses in Egyptian poultry, 2015

Kayed

Kandeil

El-Shesheny

et al. 2016

East Mediterr Health J

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Surveillance for avian influenza viruses in Egyptian poultry has been conducted since 2009. Up to 2011, all the detected viruses were H5N1, and the overall prevalence was 5%. In 2011, H9N2 viruses were observed to be co-circulating and co-infecting the same hosts as H5N1 viruses. Since then, the detection rate has increased to around 10%. In the 2014-2015 winter season, H5N1 was circulating heavily in poultry flocks and caused an unprecedented number of human infections. In contrast, surveillance in the last quarter of 2015 indicated a near absence of H5N1 in Egyptian poultry. Surveillance for avian influenza viruses must continue in Egypt to monitor further developments in H5N1 circulation in poultry. En 2011, on a remarqué que les virus H9N2 circulaient en même temps et co-infectaient les mêmes hôtes que les virus H5N1. Depuis, le taux de détection a augmenté pour atteindre près de 10 %. Pendant la saison hivernale 2014-2015, le virus H5N1 a considérablement circulé dans les élevages de volailles, entraînant un nombre d'infections sans précédent chez l'homme. À l'inverse, la surveillance au cours du dernier trimestre 2015 a constaté la quasi-absence du H5N1 dans les populations de volailles égyptiennes. La surveillance des virus de la grippe aviaire doit se poursuivre en Égypte afin de déceler les futures évolutions de la circulation du H5N1 dans les populations de volailles.

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“…The number of affected countries increased during 2003−2008, and infections spread from East and Southeast Asia to West Asia and several regions of Africa ( 2 ). The highest cumulative number of confirmed human cases was reported in Egypt ( 3 , 4 ). This virus has been detected in poultry and wild birds in >50 countries, and the virus is epizootic in Bangladesh, China, Egypt, India, Indonesia, and Vietnam ( 5 ).…”

mentioning

confidence: 99%