University of Veterinary Science, Yezin, Myanmar.
School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia.
Prev Vet Med. 2022 Oct;207:105657. doi: 10.1016/j.prevetmed.2022.105657. Epub 2022 Apr 26.
High mortality in young chicks and deaths from Newcastle disease (ND) are the two major constraints to village chicken production in low-and middle-income countries. A 12-month intervention study was conducted across 174 households in two townships of Central Myanmar, to reduce these chicken mortalities. Interventions included ND vaccinations of village chickens and improved chick management. Following the Health Belief Model (HBM) framework, 81 village chicken farmers involved in the intervention study were repeatedly surveyed before and after the interventions to determine the level of change in farmers' knowledge about ND, perceptions about susceptibility and severity of ND virus infection, perceptions about benefits and barriers of ND vaccination, as well as farmers' actions to improve the health status of their birds and to improve biosecurity and ND control measures. Marginal homogeneity tests were used to compare the level of change in farmers' matched responses to individual survey questions before and after the interventions. In addition, confirmatory factor analysis and structural equation modelling was used to create latent variables describing farmers' perceptions about susceptibility and severity of ND in their birds, farmers' perceptions about the barriers and benefits of conducting ND vaccination as well as farmers' cues to action and self-efficacy before and after the interventions. Interventions resulted in 33% more chicks surviving, which resulted in increased sales of birds after they had reached a market age of 7 months. After the interventions, farmers acknowledged the value of protecting birds from ND to increase their income (p = 0.0002). Farmers were also more willing to overcome barriers to vaccination (i.e., 'catching' birds for ND vaccinations) after the interventions (p = 0.0388). Interestingly, after the interventions, fewer farmers were concerned about the risk of their birds becoming infected with ND virus through cock fights and non-confinement (p = 0.0008 and p = 0.00022, respectively), and farmers were more uncertain about the susceptibility of their birds to ND virus infection after the interventions. Surprisingly, farmers became 'less active' in ensuring good biosecurity practices after the interventions: fewer farmers were willing to observe disease signs in village chickens (p < 0.001) and fewer farmers buried dead birds (p < 0.001). Perceived susceptibility was the only HBM component that was significantly reduced (p = 0.014) after the interventions: thus, less farmers were concerned about ND even when using management practices associated with high risk of ND transmission (e.g., cook fights, no confinement). Our results highlight the importance of information campaigns and extension work to ensure farmers maintain a high level of biosecurity when animal health interventions are implemented.
高死亡率的小鸡和因新城疫（ND）而死亡，是中低收入国家乡村养鸡生产的两大制约因素。在缅甸中部的两个乡镇的 174 户家庭中进行了为期 12 个月的干预研究，以降低这些鸡的死亡率。干预措施包括对乡村鸡进行 ND 疫苗接种和改善小鸡管理。根据健康信念模型（HBM）框架，参与干预研究的 81 名乡村养鸡户在干预前后进行了多次调查，以确定农民对 ND 的认识水平、对 ND 病毒感染易感性和严重程度的看法、对 ND 疫苗接种的益处和障碍的看法，以及农民改善其禽类健康状况、改善生物安全和 ND 控制措施的行动。边际同质性检验用于比较干预前后农民对个别调查问题的匹配反应水平的变化。此外，还使用验证性因子分析和结构方程模型创建了描述农民对其禽类 ND 易感性和严重程度的看法、农民对 ND 疫苗接种障碍和益处的看法以及农民在干预前后的行为线索和自我效能的潜在变量。干预措施使 33%的小鸡存活下来，这导致 7 个月大达到销售年龄的鸡的销售量增加。干预后，农民认识到保护鸡免受 ND 以增加收入的价值（p=0.0002）。农民也更愿意克服疫苗接种的障碍（即，为 ND 疫苗接种“捕捉”鸟类）（p=0.0388）。有趣的是，干预后，较少的农民担心斗鸡和非禁闭会使他们的鸡感染 ND 病毒的风险（p=0.0008 和 p=0.00022），并且农民对其禽类对 ND 病毒感染的易感性也不太确定。令人惊讶的是，农民在干预后在确保良好生物安全措施方面变得“不那么活跃”：较少的农民愿意观察乡村鸡的疾病迹象（p<0.001），也较少的农民埋葬死鸡（p<0.001）。感知易感性是干预后唯一显著降低的 HBM 组成部分（p=0.014）：因此，即使使用与 ND 传播风险较高相关的管理措施（例如，斗鸡、不禁闭），农民对 ND 的担忧也会减少。我们的研究结果强调了信息宣传和推广工作的重要性，以确保农民在实施动物健康干预措施时保持高水平的生物安全。
