TITLE:
Newcastle Disease Virus Isolation and Its Prevalence in Uganda Poultry Farms
AUTHORS:
Keneth Iceland Kasozi, Paul Ssuna, Dickson Stuart Tayebwa, Mohd Alyas
KEYWORDS:
Newcastle Disease Virus; Chicken Embryo Virus Isolation; Poultry Farmers in Uganda; Avain Viruses in Africa; Animal Production Challenges
JOURNAL NAME:
Open Journal of Veterinary Medicine,
Vol.4 No.1,
January
14,
2014
ABSTRACT: The present research work was carried out to isolate and
identify Newcastle disease virus (NDV) by using haemagglutination inhibition
(HI) test and HA-HI virus isolation, embryonated eggs (EE) and chicken embryo
fibroblasts (CEF). A total of 95 clinical (blood, tracheal and cloacal swabs)
and post-mortem (brain, lung, colon and spleen) samples were collected from
chickens of field outbreaks of suspected Newcastle disease virus (NDV). The HI
and HA-HI were employed to detect NDV in tissue homogenates of all the clinical
and post-mortem samples as well as laboratory samples (AF and ICF). Among the four
different types of post-mortem samples, virus isolation rate was found to be
low in body organs. In CEF cell culture system, the rate of virus isolation
from all the aforesaid samples was found to be at 100% with the exception of
serum samples; while in tracheal and cloacal swabs, it was at 90%; while
in serum, it was at 10%, in all clinical cases. The isolation rate of
NDV was higher in CEF culture system (66.7%) compared to that of avian embryos
(33.3%). Samples were inoculated and the allantoic fluid (AF) of the dead
embryos and the infected culture fluid (ICF) of the CEF were harvested at 24 to
96 hours of the post-infection, respectively, which revealed that the virulent
strain of NDV is highly prevalent in the region. The prevalence of NDV
was established at 1.1%, 2.1% and 4.2% using HA-HI, EE, and CEF methods. Rapid
detection and identification of the virus are crucial for the
effective control of the disease as conventional diagnostic methods such as
virus isolation on embryonated eggs followed by serological identification in
haemagglutination-inhibition test are laborious and time-consuming. The
speed of the diagnosis can be considerably increased by using methods based on
molecular biology, e.g. reverse transcription—polymerase chain reaction. However, the
genetic variability of APMV-1 isolates should be considered carefully as the potential
cause for false negative results of genetic-based laboratory tests.