Study on severe poultry diseases: Strengthening local veterinary capacity from post-mortem to laboratory diagnosis
In Vietnam field veterinarians often carry out a post-mortem (necropsy) to diagnose the cause of poultry diseases. However, good post-mortem requires a deep knowledge of current diseases circulating in the region and a comprehensive understanding of poultry lesions, in addition to confirmatory diagnostics. Due to high costs, current diagnostic capacity is focused on Highly Pathogenic Avian Influenza (HPAI) and Newcastle Disease (ND). To address the problem, ViParc is supporting the laboratory of the Sub-Department of Animal Health and Production in Dong Thap (SDAHP-DT) with relevant training provided to both field and laboratory veterinarians. These facilities are one of the key factors that strengthen the SDAHP-DT laboratory to be able to perform modern diagnostic techniques independently. These techniques include molecular tests (RT-PCR) for viral and bacterial detection, as well as microbiological (bacterial isolation, antimicrobial susceptibility testing of pathogens), and parasitological techniques.
ViParc and SDAHP-DT have recently commenced a poultry disease surveillance study which will investigate chicken diseases in eight districts. The study is being implemented through a poultry veterinarian network to help provide diagnostic service for chicken farmers. When farmers bring their sick chickens to these vets, the vets will introduce this cost-free diagnostic study. Eligible farmers will then be invited to join, providing basic information related to poultry practice as well as two chickens for post-mortem and laboratory diagnosis.
The study focuses on 10 pathogens known to cause severe respiratory and septicaemic diseases. These include six bacteria (Pasteurella multocida, Avibacterium paragallinarum, Ornithobacterium rhinotracheale, Mycoplasma gallisepticum, Escherichia coli, and Salmonella pullorum/gallinarum) and four viral agents (Infectious Bronchitis Virus, Avian Influenza, Newcastle Virus, and Marek’s Disease). Pathogenic bacteria will be isolated using suitable agar media, and viruses will be confirmed by molecular techniques (RT-PCR). The isolated pathogens will also be further investigated for their susceptibility to antimicrobial agents.
Results from each investigation will be fed back to the participating veterinarian and farmer. Results from bacterial culture will be provided within four days. The other test results will be given to all participants as a summary report at the end of the study, which is expected to investigate 160 cases across eight districts from September 2017 to January 2018. These results will provide ViParc scientists with a very valuable knowledge of the main pathogens circulating in the region, helping veterinarians and farmers alike to better control diseases and thus reduce antimicrobial usage.