State Veterinary Services, Department of Rural Development and Agrarian Reform, Lady Frere, 5410, South Africa; Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, 0110, South Africa; Discipline of Veterinary Sciences, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, 4811, Australia.
Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, 0110, South Africa.
Prev Vet Med. 2021 Sep;194:105430. doi: 10.1016/j.prevetmed.2021.105430. Epub 2021 Jul 12.
The source of emerging diseases and antimicrobial resistance is of increasing interest to epidemiologists. This paper looks at village chickens as such a source. In addition, infectious diseases constitute a major challenge to the growth and profitability of the rural poultry sector in Sub-Saharan Africa. A serological survey was conducted to estimate the apparent seroprevalence of selected chicken diseases in the Eastern Cape Province of South Africa alongside a sociological survey of poultry farmers and the remedies most commonly used to prevent diseases in their flocks. Sera collected from village chickens (n = 1007) in the province were screened for specific antibodies against Newcastle disease (ND), avian influenza (AI), avian infectious bronchitis (IB) and Mycoplasma gallisepticum (MG). The overall seroprevalence of ND, AI, IB and MG in the province was found to be 69.2 % (95 % CI 51.9-86.5%); 1.8 % (95 % CI 0.2-3.4%); 78.5 % (95 % CI 74.9-82%) and 55.8 % (95 % CI 41.3-70.3%) respectively with clustering found at the District level. Cross hemagglutination inhibition (HI) tests indicated that the chickens were exposed to the ND vaccine. AI ELISA-positive samples were tested using HIs against the H5, H6 and H7-subtypes, but only H6-specific antibodies were detected. Avian influenza strains shared the common ancestor responsible for the 2002 chicken outbreak in KwaZulu-Natal Province. The majority of chicken farmers were females and pensioners (69 % and 66.1 % respectively) and had a primary school education (47.1 %). Traditional remedies were commonly used by farmers (47.15 %) and among the remedies, Aloe plant (Aloe ferox Mill.) or ikhala (Xhosa) was the most commonly used product (28.23 %) for preventing and reducing mortalities among village chickens. The findings stress the importance of village chickens as a substitute for social welfare and highlight the exposure of village chickens to important chicken pathogens. The economic impact of these pathogens on the development of this sub-sector needs further investigation. Village chickens are a potential source of virulent Newcastle disease virus (NDV) because of the lack of vaccination and biosecurity. They may serve as amplification hosts which increases the probability that virulent NDV could spill over into commercial poultry flocks due to large amounts of circulating virus. The zoonotic threat of circulating H6N2 viruses raise concern due to their mutation and reassortment among chickens and a potential movement of infected birds within the province. Finally, the use of antibiotics by untrained chicken farmers constitute another major concern as it could serve as a source of antimicrobial resistance (AMR).
新兴疾病和抗菌素耐药性的源头越来越引起流行病学家的关注。本文探讨了农村家禽作为此类源头的作用。此外,传染病对撒哈拉以南非洲农村家禽业的增长和盈利能力构成了重大挑战。进行了血清学调查,以估计南非东开普省选定鸡病的明显血清流行率,同时对家禽饲养者进行了社会学调查,并调查了他们在禽类中最常使用的预防疾病的方法。从该省的农村家禽(n = 1007)中采集的血清用于针对新城疫(ND),禽流感(AI),禽传染性支气管炎(IB)和鸡毒支原体(MG)的特异性抗体进行筛查。该省 ND,AI,IB 和 MG 的总体血清流行率分别为 69.2%(95%CI 51.9-86.5%);1.8%(95%CI 0.2-3.4%);78.5%(95%CI 74.9-82%)和 55.8%(95%CI 41.3-70.3%),在地区一级发现了聚类现象。交叉血凝抑制(HI)试验表明,鸡暴露于 ND 疫苗。使用针对 H5,H6 和 H7 亚型的 HI 对 AI ELISA 阳性样本进行了测试,但仅检测到 H6 特异性抗体。禽流感株与负责 2002 年夸祖鲁-纳塔尔省鸡群暴发的共同祖先共享。大多数家禽饲养者是女性和养老金领取者(分别为 69%和 66.1%),并接受过小学教育(47.1%)。农民通常使用传统药物(47.15%),其中,Aloe 植物(Aloe ferox Mill.)或 ikhala(Xhosa)是用于预防和减少农村鸡群死亡率的最常用产品(28.23%)。研究结果强调了农村家禽作为社会福利替代物的重要性,并突出了农村家禽接触重要的家禽病原体的情况。这些病原体对该部门发展的经济影响需要进一步调查。由于缺乏疫苗接种和生物安全措施,农村家禽可能成为强毒新城疫病毒(NDV)的潜在来源。它们可能充当扩增宿主,由于大量循环病毒,强毒 NDV 溢出到商品家禽群中的可能性增加。由于 H6N2 病毒在鸡群中的突变和重组以及感染鸟类在省内的潜在移动,循环 H6N2 病毒构成了人畜共患威胁,引起了人们的关注。最后,未经培训的家禽饲养者使用抗生素也是另一个主要问题,因为它可能成为抗菌素耐药性(AMR)的来源。