Emergence of Highly Pathogenic Avian Influenza A Virus (H5N1) of Clade 2.3.4.4b in Egypt, 2021-2022.

Wild migratory birds have the capability to spread avian influenza virus (AIV) over long distances as well as transmit the virus to domestic birds. In this study, swab and tissue samples were obtained from 190 migratory birds during close surveillance in Egypt in response to the recent outbreaks of the highly pathogenic avian influenza (HPAI) H5N1 virus. The collected samples were tested for a variety of AIV subtypes (H5N1, H9N2, H5N8, and H6N2) as well as other pathogens such as NDV, IBV, ILT, IBDV, and WNV. Among all of the tested samples, the HPAI H5N1 virus was found in six samples; the other samples were found to be negative for all of the tested pathogens. The Egyptian HPAI H5N1 strains shared genetic traits with the HPAI H5N1 strains that are currently being reported in Europe, North America, Asia, and Africa in 2021-2022. Whole genome sequencing revealed markers associated with mammalian adaption and virulence traits among different gene segments, similar to those found in HPAI H5N1 strains detected in Europe and Africa. The detection of the HPAI H5N1 strain of clade 2.3.4.4b in wild birds in Egypt underlines the risk of the introduction of this strain into the local poultry population. Hence, there is reason to be vigilant and continue epidemiological and molecular monitoring of the AIV in close proximity to the domestic-wild bird interface.

Molecular characterization and pathological identification of a novel strain of delta papillomavirus-4 (bovine papillomavirus-2) in Egypt.

BACKGROUND AND AIM: Bovine papillomaviruses (BPV) are a heterogeneous group of oncoviruses, distributed globally, which produce major economic losses. In the current study, we compared the results of different diagnostic approaches and compared the strains identified in this study with previously characterized strains at local and international levels. MATERIALS AND METHODS: Samples of skin warts were collected from five bovines with generalized papillomatosis from two Egyptian provinces, Menya and Ismailia, in 2020. Electron microscopy, molecular characterization, histopathological, and immunohistochemical examination were performed. RESULTS: BPV was detected using electron microscopy in the collected samples. Using molecular characterization, BPV-2 was successfully identified for 1st time in Egypt. The strain has 99.6% identity with the BPV-2 reference strains obtained from GenBank. These results were supported by histopathology and immunohistochemistry examination. Partial nucleotide sequences of the L1 gene were submitted to GenBank with accession numbers MW289843 and MW289844. CONCLUSION: BPV-2 was reported for 1st time in the current study. The strain was identified grossly, microscopically, and pathologically and confirmed using molecular approaches. All results were consistent. The sequence analysis revealed that this strain has high sequence similarity to the reference Deltapapillomavirus-4, BPV-2 strains from Brazil and China.

Isolation of a Novel Reassortant Highly Pathogenic Avian Influenza (H5N2) Virus in Egypt.

Highly pathogenic avian influenza (HPAI) H5N1 and H5N8 have become endemic among domestic poultry in Egypt since 2006 and 2016, respectively. In parallel, the low pathogenic avian influenza H9N2 virus has been endemic since 2010. Despite the continuous circulation of these subtypes for several years, no natural reassortant has been detected so far among the domestic poultry population in Egypt. In this study, the HPAI (H5N2) virus was isolated from a commercial duck farm, giving evidence of the emergence of the first natural reassortment event in domestic poultry in Egypt. The virus was derived as a result of genetic reassortment between avian influenza viruses of H5N8 and H9N2 subtypes circulating in Egypt. The exchange of the neuraminidase segment and high number of acquired mutations might be associated with an alteration in the biological propensities of this virus.