Newcastle Disease Genotype VII Prevalence in Poultry and Wild Birds in Egypt.

Newcastle Disease Virus (NDV) genotype VII is a highly pathogenic Orthoavulavirus that has caused multiple outbreaks among poultry in Egypt since 2011. This study aimed to observe the prevalence and genetic diversity of NDV prevailing in domestic and wild birds in Egyptian governorates. A total of 37 oropharyngeal swabs from wild birds and 101 swabs from domestic bird flocks including chickens, ducks, turkeys, and pelicans, were collected from different geographic regions within 13 governorates during 2019-2020. Virus isolation and propagation via embryonated eggs revealed 91 swab samples produced allantoic fluid containing haemagglutination activity, suggestive of virus presence. The use of RT-PCR targeted to the F gene successfully detected NDV in 85 samples. The geographical prevalence of NDV was isolated in 12 governorates in domestic birds, migratory, and non-migratory wild birds. Following whole genome sequencing, we assembled six NDV genome sequences (70-99% of genome coverage), including five full F gene sequences. All NDV strains carried high virulence, with phylogenetic analysis revealing that the strains belonged to class II within genotype VII.1.1. The genetically similar yet geographically distinct virulent NDV isolates in poultry and a wild bird may allude to an external role contributing to the dissemination of NDV in poultry populations across Egypt. One such contribution may be the migratory behaviour of wild birds; however further investigation must be implemented to support the findings of this study. Additionally, continued genomic surveillance in both wild birds and poultry would be necessary for monitoring NDV dissemination and genetic diversification across Egypt, with the aim of controlling the disease and protecting poultry production.

Avian Paramyxovirus Type 1 in Egypt: Epidemiology, Evolutionary Perspective, and Vaccine Approach.

Avian orthoavulavirus 1, formerly known as avian paramyxovirus type-1 (APMV-1), infects more than 250 different species of birds. It causes a broad range of clinical diseases and results in devastating economic impact due to high morbidity and mortality in addition to trade restrictions. The ease of spread has allowed the virus to disseminate worldwide with subjective virulence, which depends on the virus strain and host species. The emergence of new virulent genotypes among global epizootics, including those from Egypt, illustrates the time-to-time genomic alterations that lead to simultaneous evolution of distinct APMV-1 genotypes at different geographic locations across the world. In Egypt, the Newcastle disease was firstly reported in 1947 and continued to occur, despite rigorous prophylactic vaccination, and remained a potential threat to commercial and backyard poultry production. Since 2005, many researchers have investigated the nature of APMV-1 in different outbreaks, as they found several APMV-1 genotypes circulating among various species. The unique intermingling of migratory, free-living, and domesticated birds besides the availability of frequently mobile wild birds in Egypt may facilitate the evolution power of APMV-1 in Egypt. Pigeons and waterfowls are of interest due to their inclusion in Egyptian poultry industry and their ability to spread the infection to other birds either by presence of different genotypes (as in pigeons) or by harboring a clinically silent disease (as in waterfowl). This review details (i) the genetic and pathobiologic features of APMV-1 infections in Egypt, (ii) the epidemiologic and evolutionary events in different avian species, and (iii) the vaccine applications and challenges in Egypt.

Prevalence of bacteria and parasites in White Ibis in Egypt.

A field survey was conducted to evaluate the prevalence of bacterial infections among free-living White Ibis (Nipponia nippon) in which 92 bacterial isolates were recovered from 193 different internal organs of 55 apparently healthy Ibis. Escherichia coli and Salmonella spp. were isolated at rates of 43.6% and 14.5%, respectively. The other bacterial pathogens isolated were Shigella spp. (34.5%), Enterobacter spp. (21.8%) Citrobacter spp. (18.1%), Klebsiella pneumonia (16.3), Staphylococcus aureus (10.9%) and Proteus mirabilis (7.2%). The antibiogram indicated that all isolates were highly sensitive to ciprofloxacin, enrofloxacin, trimethoprim and penicillin. Penicillin was most effective against S. aureus. An examination of the gastrointestinal tract revealed the presence of a nematode, Ascaris (Porroceacum ensicaudatum), and three trematodes (Echinochasmus perfoliatus, Apatemon aracilis and Patagifer bilobus). Other trematodes were detected in enlarged gall bladder and kidney lesions. Histopathological examination showed signs of hepatitis. The gall bladder had cholangitis, cholicystitis which may have been caused by trematode infestation. The kidneys also showed multiple parasitic cysts of trematodes and non-suppurative interstitial nephritis. This study suggests the possible role of the White Ibis, when living near poultry populations, in transmitting certain pathogens to poultry.