Cormorants as a Potentially Important Reservoir and Carrier of Newcastle Disease Virus on the Asian Continent

Abstract

Despite numerous disease prevention measures and control programs, Newcastle disease (ND) remains one of the most significant infections in poultry worldwide, especially in developing countries. It is known that wild birds, mainly of the Anseriformes order, are the main carrier of lentogenic (non-pathogenic) variants of Newcastle disease virus (NDV) in nature. But the question of the reservoir of velogenic (highly pathogenic) NDV in nature still remains open. In the 1970s, 1990s, and 2000s in North America during epizootics among cormorants, velogenic NDV strains were isolated. It was later concluded that cormorants play an important role in the maintenance and circulation of NDV in North America. New data have been obtained on the circulation of velogenic NDV strains in wild birds in Central Asia: VIIb and XIII genotype strains were isolated from cormorants for the first time in Kazakhstan. Interestingly, outbreaks of NDV registered in poultry in Central and Southern Asia were phylogenetically close to the viruses from cormorants that support the idea that cormorants can serve as the potential reservoir of velogenic NDV in developing countries of Asia. The seasonal migrations of cormorants may contribute to the distribution of the virus throughout Asia but more evidence must be obtained to confirm this hypothesis. There is increasing evidence of the introduction of NDV into the poultry farms from wild nature worldwide. This article continues the discussion on the likelihood of cormorants to serve as a reservoir and carrier of NDV on the Asian continent.

Analysis of Avian Orthoavulavirus 1 Detected in the Russian Federation between 2017 and 2021

“…According to the results of monitoring studies conducted in Kazakhstan and covering 73 species of birds, virulent viruses were detected only in pigeons (Columbiformes) and a velogenic NDV of genotype XIII was also detected in cormorants [ 35 ]. The results of a recent study of ND outbreaks in Kazakhstan indicate that NDV outbreaks of genotype VIIb (according to the classification of Diel et al) in Central Asia are associated with cormorant migration [ 36 ]. These studies confirm the role of wild and synanthropic birds in the spread of AOAV-1 in poultry.…”

Emerging and Novel Viruses in Passerine Birds

“…Wild birds, especially Anseriformes, are the main carriers of non-pathogenic NDV variants [ 121 ] but highly pathogenic strains have been isolated from cormorants in North America and Central Asia, some linked to mass avian mortality events [ 122 ]. However, the effect on passerines is poorly understood.…”

An Outbreak of Newcastle Disease Virus in the Moscow Region in the Summer of 2022

“…The serotypes, classes, and genotypes as well as the year of isolation and the source of isolation are indicated: wild birds (W), pigeons (Pi), and poultry (Ch). If the pathogenicity of the virus was established in the cited work, then it is indicated by color: red indicates pathogenic isolates and green indicates non-pathogenic isolates [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , …”