Role of Pigeons in the Transmission of Avian Avulavirus (Newcastle Disease-Genotype VIId) to Chickens.

Hany F Ellakany,Elsayed O.S Hussein,Ayman A Swelum,Hatem S Abd El-Hamid,Islam M Saadeldin,Ayman E Taha,Rasha E Zedan,Ahmed R Gado,Hani Ba-Awadh,Ahmed R Elbestawy,Mohamed A Soliman,Mohamed E Abd El-Hack

doi:10.3390/ani9060338

Abstract

Simple SummaryNewcastle disease is an acute fatal disease of poultry. All broiler chickens and 8/15 pigeons were killed when infected intramuscularly (IM), while 7/10 chickens and only 1/15 pigeons were killed when infected intranasally (IN) with the virus in an experimental setting. Chickens in contact with infected pigeons developed severe respiratory, digestive and nervous signs. The mortality rates in chickens in contact with IM and IN infected pigeons were 2/5 and 3/5, respectively. Chickens in contact with IM infected pigeons had higher viral shedding titres than those in contact with IN infected pigeons. Free-range pigeons are considered an efficient carrier and transmitter of NDV-VIId to commercial broiler chickens raised in open houses.Newcastle disease is an acute fatal disease of poultry. The aim of this study was to determine the dynamics of the transmission of avian avulavirus (velogenic viscerotropic Newcastle disease-genotype VIId) from either intramuscularly (IM)- or intranasally (IN) infected 8-week-old Egyptian Baladi pigeons in contact with commercial Arbor Acres broiler chickens (4 weeks of age). The mortality of IM infected chickens and pigeons was 10/10 for chickens and 8/15 for pigeons, while the mortality of IN infected chickens and pigeons was 7/10 for chickens and only 1/15 for pigeons. The concentration of viral shedding in the oropharynx was higher than that in the cloaca for both IN and IM infected pigeons. Pigeons infected IN continued shedding the virus from the oropharynx from the 4th day post-infection (dpi) up to the 16th dpi, while IM infected pigeons stopped oropharyngeal shedding at the 11th dpi. Chickens in contact with infected pigeons developed severe respiratory, digestive and nervous signs. The mortality rates in chickens in contact with IM and IN infected pigeons were 2/5 and 3/5, respectively. Chickens in contact with IM infected pigeons showed higher viral shedding titres in both the oropharynx and cloaca than chickens in contact with pigeons infected IN. In conclusion, free-range pigeons are considered an efficient carrier and transmitter of NDV-VIId compared to commercial broiler chickens raised in open houses.

Highlights

IntroductionNewcastle disease virus (NDV) class II contains at least 18 genotypes that include virulent and avirulent viruses [4,5,6,7]
Avian avulavirus 1 or avian paramyxovirus type 1 is the cause of virulent Newcastle disease outbreaks characterized by high morbidity and mortality rates in susceptible birds [1,2,3].Newcastle disease is classified as a list A disease by the Office International des Epizooties [3].Newcastle disease virus (NDV) class II contains at least 18 genotypes that include virulent and avirulent viruses [4,5,6,7]
The severe nervous signs and paralysis in the experimentally-infected pigeons in this study were similar to those reported by Marlier and Vindevogel [27], who indicated that the clinical signs observed in pigeons were similar to those induced by neurotropic NDV

Summary

Introduction

Newcastle disease virus (NDV) class II contains at least 18 genotypes that include virulent and avirulent viruses [4,5,6,7]. Before 2013, all of the isolated NDV strains in Egypt belonged to class II, genotypes II and VI. Radwan et al [8] first reported the incidence of three outbreaks of NDV class II, genotype VII, subgenotype d (lineage 5 sub-lineage d) in 2011–2012 in three broiler chicken flocks. Abdel-Glil et al [9] and Hussein et al [10] indicated that most of the recent circulating Egyptian NDV isolates from chickens belonged to class II, genotype VII, subgenotype d

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