Epizootic situation concerning especially dangerous viral infections among birds of South Ukraine

Abstract

Aim of the work was monitoring of especially dangerous and economically significant poultry infections in the South of Ukraine. The research was conducted at the Odessa Research Station of the National Scientific Center “Institute of Experimental and Clinical Veterinary Medicine” and in the Testing Center of the Odessa Regional State Laboratory of the State Service of Ukraine on Food Safety and Consumer Protection. The corpses of dead birds were subjected to autopsy; meanwhile biological material was picked up for research. Serological tests for Newcastle disease were performed in HIT with a virus dose of 4 UHA in a titer of 1:8 and higher. In addition to common bacteriological studies the presence of bacterial associates was determined. Serological tests of 365 samples of blood from poultry from 73 settlements, 16 samples from wild and 18 samples from synanthropic birds of Odessa Region, did not reveal antibodies to avian influenza virus of subtype H5. The presence of the formed group immunity against the causative agent of Newcastle disease was detected in the farmsteads of 118 settlements and in 10 industrial poultry farms (seropositivity is 80–100%). Antibodies against the pathogen of Newcastle disease in the blood sera from wild birds from Odessa Region were not detected. In the summer-autumn season, some outbreaks of the Newcastle disease among ornamental pigeons were detected in three farms of two settlements. Mortality was 50–70%. Studying of 15 blood samples from pigeons detected antibodies to Newcastle disease virus (antibody titer 4.0–7.1 log2). Autopsy of 28 poultry carcasses revealed changes characteristic of infectious laryngotracheitis of chickens, as well as some diseases of bacterial (tuberculosis, pasteurellosis, escherichiosis) and protozoan (trichomoniasis of chickens) etiology. Monitoring data on particularly dangerous viral infections of poultry in the South of Ukraine indicate the stability of the epizootic situation. The absence of hemagglutinating antibodies to avian influenza virus of the H5 subtype in the populations of the studied birds of different species and the presence of the formed group immunity against the Newcastle disease pathogen were established; seropositivity is 80–93 %. The circulation of Newcastle disease virus among ornamental pigeons has been established