Department of Global Health and Biomedical Sciences, School of Life Sciences, Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tengeru, Tanzania.
College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, P.O. Box 3015, Morogoro, Tanzania.
Trop Anim Health Prod. 2022 Jun 15;54(4):214. doi: 10.1007/s11250-022-03198-4.
The present study intended to determine the prevalence of Newcastle disease in unvaccinated backyard poultry in Africa. Using the PRISMA approach, a systematic review and meta-analysis of 107 epidemiological studies was conducted. The meta-analysis identified significant variation of both seroprevalence (I = 99.38, P = 0.00) and Newcastle disease virus prevalence (I = 99.52, P = 0.00) reported in various studies included in this review. Publication bias was not detected in either case. Seroprevalence of Newcastle disease was 40.2 (95%CI 32.9-47.8). Seroprevalence was significantly influenced by sampling frame and the African region where the studies were conducted. The prevalence of Newcastle disease virus (NDV) was 12% (95%CI 7.3-17.8), and the variation was influenced by sampling frame, diagnostic test, and regions where the studies were conducted. Also, Newcastle disease (ND) accounted for 33.1% (95%CI 11.9-58.1) of sick chickens. Results also indicated that genotypes VI and VII are widely distributed in all countries included in the study. However, genotype V is restricted in East Africa, and genotypes XIV, XVII, and XVIII are restricted in West and Central Africa. On the other hand, genotype XI occurs in Madagascar only. In addition, virulent genotypes were isolated from apparently healthy and sick birds. It is concluded that several genotypes of NDV are circulating and maintained within the poultry population. African countries should therefore strengthen surveillance systems, be able to study the viruses circulating in their territories, and establish control programs.
本研究旨在确定非洲未接种疫苗的后院家禽中新城疫的流行情况。采用 PRISMA 方法，对 107 项流行病学研究进行了系统评价和荟萃分析。荟萃分析确定了本综述中包含的各种研究报告的血清阳性率（I=99.38，P=0.00）和新城疫病毒阳性率（I=99.52，P=0.00）均存在显著差异。在这两种情况下均未发现发表偏倚。新城疫血清阳性率为 40.2%（95%CI 32.9-47.8）。血清阳性率受到采样框架和进行研究的非洲地区的显著影响。新城疫病毒（NDV）的流行率为 12%（95%CI 7.3-17.8），变异受到采样框架、诊断测试和进行研究的地区的影响。此外，新城疫（ND）占病鸡的 33.1%（95%CI 11.9-58.1）。结果还表明，基因型 VI 和 VII 广泛分布于研究中包含的所有国家。然而，基因型 V 仅局限于东非，基因型 XIV、XVII 和 XVIII 局限于西非和中非。另一方面，基因型 XI 仅出现在马达加斯加。此外，从看似健康和患病的鸟类中分离出了毒力基因型。因此得出结论，几种基因型的 NDV 在禽类群体中传播和维持。非洲国家应加强监测系统，能够研究其领土内循环的病毒，并建立控制计划。
