Circulation of type A/H5 highly pathogenic avian influenza viruses on poultry in Dong Thap province

Abstract

The objective of this study aimed at investigating the prevalence of the H5 highly pathogenic avian
influenza viruses (H5 HPAIVs) in poultry in Dong Thap province during the period of 2019–2020.
Epidemiological data used in this study was obtained from the result of the retrospective investigation programme on livestock situation, H5 HPAI surveillance data in poultry in Dong Thap during the study period, these information were provided by Sub-Department of Animal husbandry, Animal health and Fisheries. The studied results showed that the detection rate of H5 HPAIVs in the surveyed samples (including chickens, ducks and environmental samples) in 2020 was 13.7% (43/312), this rate in 2019 was 7.00% (18/228). In addition, all three types of the collected samples were found to be positive with H5 HPAIVs in which the duck samples were detected with the highest positive sample rate with 83.33% (15/18) in 2019 and 69.77% (30/43) in 2020, respectively. The results obtained from our study also indicated that there was co-circulation of both H5N1 and H5Nx subtypes of H5 HPAIVs in poultry in Dong Thap province and circulating proportion of these subtypes varied over the years. Assessment
of correlation between poultry density and prevalence of H5 HPAIVs among the areas in Dong Thap province showed that the areas having high poultry density (over 15–20 birds/ha), such as: Sa Dec city and Chau Thanh district, all had the presence of H5 HPAIVs in a certain proportion.