Genetic characterization of highly pathogenic H5N1 avian influenza viruses isolated from poultry farms in Egypt

Eladl, Abd Elfattah H.; IAbou.Elazm, Kamel; Ismail, A. M.; Ali, Ahmed; Saif, Y. M.; Lee, Chang-Won

doi:10.1007/s11262-011-0633-5

Cited by 22 publications

(13 citation statements)

References 22 publications

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“…Here, for the first time, the isolation of H9N2 virus in Egypt is described. Despite previous intense surveillance activities conducted by our team and others in the context of H5N1 endemicity in Egypt, H9 viruses had not been detected before [6,7,13,22]. In the present investigation, close sequence and phylogenetic identities with the G1-like H9N2 virus currently circulating in the neighbouring countries could indicate further spread of the virus into Egypt as a part of its extensive circulation in the nearby countries rather than a separate introduction from the Eastern Asian AIV epicentre.…”

contrasting

confidence: 54%

Isolation of H9N2 avian influenza virus from bobwhite quail (Colinus virginianus) in Egypt

El-Zoghby¹,

Arafa²,

Hassan³

et al. 2012

Arch Virol

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This study describes the first isolation of H9N2 avian influenza virus (AIV) from commercial bobwhite quail (Colinus virginianus) in Egypt. Infected birds showed neither clinical signs nor mortality. Virus isolation and real-time reverse transcription polymerase chain reaction confirmed the presence of the H9N2 virus in cloacal swab samples collected at 35 days of age and the absence of other AIV subtypes, including H5 and H7. The hemagglutinin and neuraminidase genes of the isolated virus showed 99.1% and 98.2% nucleotide identity and 97.3% and 100% amino acid identity, respectively, to those of H9N2 viruses currently circulating in poultry in the Middle East. Phylogenetically, the Egyptian H9N2 virus was closely related to viruses of the G1-like lineage isolated from neighbouring countries, indicating possible epidemiological links.

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confidence: 54%

Isolation of H9N2 avian influenza virus from bobwhite quail (Colinus virginianus) in Egypt

El-Zoghby¹,

Arafa²,

Hassan³

et al. 2012

Arch Virol

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“…On the contrary, poultry industry still is in strong need of more aggressive bio-security measures, monitoring of the susceptible and already vaccinated poultry flocks. These speculations go along with El-Zoghby et al [25] and Eladl et al [29].…”

Section: Oligonucleotide Primerssupporting

confidence: 60%

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

MA¹,

Yi²,

Zeedy³

2014

Poult Fish Wildl Sci

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Surveillance on Avian Influenza Virus in Egypt during 2012 -2013 was undertaken to update the epidemiology of avian influenza virus infections among poultry flocks in Egypt. A total of 148 commercial chicken farms were tested by single-plex RT-PCR for direct detection of avian influenza viruses using type A specific nucleoprotein (NP) gene primer sets. The results revealed 5 positive chicken flocks infected with type-A AIV. These viruses were successfully isolated and propagated in SPF eggs. H5N1/HI test was positive only for three chicken flocks. Subtype specific (RT-PCR) revealed 3 positive H5 chicken flocks (2%) and 2 positive H9 chicken flocks (1.35%). All examined chicken flocks were negative for H7 subtype. Multiplex RT-PCR using H5, H7 and H9 subtypes specific primers confirmed these results. This shows the continuous co-circulation of the AIV H5 and H9 in commercial chicken flocks in Egypt complicating the respiratory problems in affected flocks. Egypt between 2012 -2013. Swabs were placed in 1-2 ml isotonic phosphate buffered saline (PBS) PH 7.0-7.4, chilled immediately on frozen gel packs and submitted to the laboratory as quickly as possible.Tracheal and cloacal swabs collected from each commercial poultry flock were pooled separately. Tracheal swabs were screened with RT-PCR for AIV detection, but cloacal swabs in PBS with antibiotics were subjected for virus isolation. AntiserumSpecific polyclonal antiserum against avian influenza subtype H5N1 was obtained from X-OVO (flock screen, Batch: 1/09) produced by OIE/FAO and National

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“…On the contrary, viruses cluster in clade 2.2.1.1, also known as variant 2.2.1 viruses, had extensive amino acids substitutions in or adjacent to the immunogenic epitopes at the proximal globular head region of the HA protein which could enable continuous circulation of the virus in and among commercial poultry despite large scale vaccination campaigns [16,17]. Regular nationwide active, passive and targeted surveillance revealed that HPAV H5N1 is perpetuated in many commercial farms, backyards and live bird markets (LBM) [4,7,9,16,18]. Culling of infected birds occurs infrequently in Egypt [6].…”

Section: Resultsmentioning

confidence: 99%

Isolation of avian influenza H5N1 virus from vaccinated commercial layer flock in Egypt

El-Zoghby¹,

Arafa²,

Kilany³

et al. 2012

Virol J

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BackgroundUninterrupted transmission of highly pathogenic avian influenza virus (HPAIV) H5N1 of clade 2.2.1 in Egypt since 2006 resulted in establishment of two main genetic clusters. The 2.2.1/C group where all recent human and majority of backyard origin viruses clustered together, meanwhile the majority of viruses derived from vaccinated poultry in commercial farms grouped in 2.2.1.1 clade.FindingsIn the present investigation, an HPAIV H5N1 was isolated from twenty weeks old layers chickens that were vaccinated with a homologous H5N1 vaccine at 1, 7 and 16 weeks old. At twenty weeks of age, birds showed cyanosis of comb and wattle, decrease in egg production and up to 27% mortality. Examined serum samples showed low antibody titer in HI test (Log2 3.2± 4.2). The hemagglutinin (HA) and neuraminidase (NA) genes of the isolated virus were closely related to viruses in 2.2.1/C group isolated from poultry in live bird market (LBM) and backyards or from infected people. Conspicuous mutations in the HA and NA genes including a deletion within the receptor binding domain in the HA globular head region were observed.ConclusionsDespite repeated vaccination of layer chickens using a homologous H5N1 vaccine, infection with HPAIV H5N1 resulted in significant morbidity and mortality. In endemic countries like Egypt, rigorous control measures including enforcement of biosecurity, culling of infected birds and constant update of vaccine virus strains are highly required to prevent circulation of HPAIV H5N1 between backyard birds, commercial poultry, LBM and humans.

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Genetic characterization of highly pathogenic H5N1 avian influenza viruses isolated from poultry farms in Egypt

Cited by 22 publications

References 22 publications

Isolation of H9N2 avian influenza virus from bobwhite quail (Colinus virginianus) in Egypt

Isolation of H9N2 avian influenza virus from bobwhite quail (Colinus virginianus) in Egypt

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

Isolation of avian influenza H5N1 virus from vaccinated commercial layer flock in Egypt

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