Dagnaw Melkie, Alemu Yilhal Getachew, Admassu Bemrew, Demessie Yitayew
Department of Veterinary Clinical Medicine, College of Veterinary Medicine and Animal Science, University of Gondar, Gondar, Ethiopia.
Department of Biomedical Science, College of Veterinary Medicine and Animal Science, University of Gondar, Gondar, Ethiopia.
Vet Anim Sci. 2025 Aug 23;30:100499. doi: 10.1016/j.vas.2025.100499. eCollection 2025 Dec.
Enzootic bovine leukosis (EBL) causes severe economic losses and is a contagious disease caused by the Bovine Leukemia Virus (BLV), belonging to the delta retrovirus of the Retroviridae family. Thus, this review aimed to estimate the global pooled prevalence of enzootic bovine leukosis and investigate its host range, focusing on cattle and sheep. We used seven databases which include PubMed, Science Direct, HINARI, Scopus, Google Scholar, Web of Science, and AJOL. The included studies (50 articles), conducted between 1992 and 2024, represent diverse geographic regions: Asia, North America, Africa, South America, and Europe. 346,917 animals were involved, of which 99,620 involved positive for BLV. The meta-analysis estimated a pooled BLV prevalence of 19% (95% CI: 16%-23%) using random effect model, though significant heterogeneity existed across studies (I² = 99.6%, p < 0.001). Subgroup analysis revealed that the highest prevalence of EBL was in North America (43%), followed by Asia (17%), Africa (14%), South America (10%), and the lowest in Europe (4%). Analysis by publication year revealed that the prevalence of EBL was 32% after 2016, whereas it was 29% before 2016. Among animal species, beef cattle exhibited the highest prevalence (26%), followed by overall cattle (20%), sheep (19%), and dairy cattle (18%). Geographical and temporal trends revealed varying prevalence rates, with notable high rates in North America and lower rates in regions such as Europe. It is crucial that North America adopt stricter prevention programs, similar to those in Europe, to reduce transmission of EBL and its economic and health impacts on livestock.
地方流行性牛白血病（EBL）会造成严重的经济损失，它是一种由牛白血病病毒（BLV）引起的传染病，该病毒属于逆转录病毒科的δ逆转录病毒。因此，本综述旨在估计全球地方流行性牛白血病的合并流行率，并研究其宿主范围，重点关注牛和羊。我们使用了七个数据库，包括PubMed、Science Direct、HINARI、Scopus、谷歌学术、科学网和AJOL。纳入的研究（50篇文章）在1992年至2024年期间开展，代表了不同的地理区域：亚洲、北美洲、非洲、南美洲和欧洲。涉及346,917只动物，其中99,620只BLV检测呈阳性。荟萃分析使用随机效应模型估计BLV的合并流行率为19%（95%置信区间：16%-23%），不过各研究之间存在显著异质性（I² = 99.6%，p < 0.001）。亚组分析显示，EBL流行率最高的是北美洲（43%），其次是亚洲（17%）、非洲（14%）、南美洲（10%），欧洲最低（4%）。按出版年份分析显示，2016年后EBL的流行率为32%，而2016年前为29%。在动物种类中，肉牛的流行率最高（26%），其次是总体牛（20%）、绵羊（19%）和奶牛（18%）。地理和时间趋势显示出不同的流行率，北美洲的流行率显著较高，而欧洲等地区的流行率较低。北美洲至关重要的是要像欧洲那样采取更严格的预防措施，以减少EBL的传播及其对牲畜的经济和健康影响。
