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Highly pathogenic avian influenza (HPAI) is a zoonotic disease that can affect both poultry and humans. Since 2005, the Vietnam government has implemented a national vaccination campaign to prevent the spread of avian influenza (AI). In 2021, the first outbreak of HPAI H5N8 was reported in a chicken farm in Quang Ninh province. To understand the stakeholders linked to the AI campaign, and their roles within the vaccine supply chain, we conducted a cross-sectional study from November 2021–January 2022. We purposively selected 114 participants, including 71 poultry farmers using HPAI vaccines, 16 veterinary drug store owners, 18 commune animal health workers (CAHWs), 8 staff from the Centers for Agricultural Services (ATSCs), and one vaccine distributor who were interviewed face-to-face using a structured questionnaire. Three HPAI vaccines (H5N1 clade 1 & 2.3.2.1, H5N1 clade 2.3.4 and H5N1 clade 2.3.2.1b) were used, and they were effective against the locally circulating virus strains. Distributors stored vaccines at the required temperature and transported them in appropriate vehicles. Vaccines remained in the supply chain for 3–5 months within their 12-month shelf-life period. The free government vaccination campaign, implemented by CAHWs, and administered by the ATSCs, reached 61% of small-scale poultry farms with a 1.21% vaccine wastage rate. Large-scale poultry farms followed the national campaign but paid a fee for the vaccines. We recommend expanding the support for AI vaccination to increase the vaccination rate among large-scale poultry farms, selecting higher efficacy seed vaccines, and that smaller dose vaccine vials are available for cost-effective vaccination.

Mosquito-borne diseases (MBDs) are causing high morbidity and mortality for humans. Urban livestock keeping is still common in cities around the world. The animals may serve as reservoirs for zoonotic MBDs, which increase the risks for humans. Here we assess the knowledge and practices related to MBDs in households with livestock and without livestock and explore the perceptions of the health care sector about MBDs and livestock keeping in Hanoi city of Vietnam in a cross-sectional study. A quantitative survey was conducted including 513 households with and without livestock-keeping in six districts and complemented with qualitative surveys with four health staff from Hanoi Center of Disease Control and three district health centers. The quantitative survey indicated that the participants possessed basic knowledge on MBDs with an average score of 18.3 out of 35, of which non-livestock-keeping households had a better knowledge than households keeping livestock (p

Presence of ducks, and in particular of free-grazing ducks, has consistently been shown to be one of the most important risk factors for highly pathogenic avian influenza outbreaks which has compromised poultry production in South-East Asia since the early 2000s and continues to threaten public health, farmers' livelihood and food security. Although free-grazing duck production has been practised for decades in South-East Asia, there are few published studies describing this production system, which is suspected to play an important role in the maintenance of avian influenza viruses. This study aimed at describing quantitatively the long-distance free-grazing duck production system in South Vietnam, characterising the movement and contact patterns of the duck flocks, and identifying potential associations between farming practices, movement and contact patterns and the circulation of avian influenza viruses. We conducted interviews among stakeholders involved in the free-grazing duck production system (duck farmers, transporters and rice paddy owners) in combination with a virological cross-sectional survey in South Vietnam. Results show that both direct and indirect contacts between free-grazing duck flocks were frequent and diverse. The flocks were transported extensively across district and province boundaries, mainly by boat but also by truck or on foot. A third of the investigated flocks had a positive influenza A virology test, indicating current circulation of avian influenza viruses, but none were positive for H5 subtypes. The age and size of the flock as well as its location at the time of sampling were associated with the risk of influenza A circulation in the flocks. These findings should be considered when developing risk assessment models of influenza virus spread aimed at informing the development of improved biosecurity practices leading to enhanced animal health, sustainable animal production and reliable income for farmers.

Background: Avian influenza (AI) is a contagious disease that causes illness and death in poultry and humans. High pathogenicity AI (HPAI) H5N6 outbreaks commonly occur in Quang Ninh province bordering China. In June 2021, the first HPAI H5N8 outbreak occurred at a Quang Ninh chicken farm. Objectives: This study examined the risk factors associated with HPAI H5N6 and H5N8 outbreaks in Quang Ninh. Methods: A retrospective case-control study was conducted in Quang Ninh from Nov 2021 to Jan 2022. The cases were households with susceptible poultry with two or more clinical signs and tested positive by real-time reverse transcription polymerase chain reaction. The controls were households in the same village as the cases but did not show clinical symptoms of the disease. Logistic regression models were constructed to assess the risk factors associated with HPAI outbreaks at the household level. Results: There were 38 cases with H5N6 clade 2.3.4.4h viruses (n = 35) and H5N8 clade 2.3.4.4b viruses (n = 3). Compared to the 112 controls, raising poultry in uncovered or partially covered ponds (odds ratio [OR], 7.52; 95% confidence interval [CI], 1.44--39.27), poultry traders visiting the farm (OR, 8.66; 95% CI, 2.7--27.69), farms with 50--2,000 birds (OR, 3.00; 95% CI, 1.06--8-51), and farms with ≥ 2,000 birds (OR, 11.35; 95% CI, 3.07--41.94) were significantly associated with HPAI outbreaks. Conclusions: Combining biosecurity measures, such as restricting visitor entry and vaccination in farms with more than 50 birds, can enhance the control and prevention of HPAI in Quang Ninh and its spread across borders. [ABSTRACT FROM AUTHOR]