Benavides Bibiana, Monti Gustavo
Animal Health Department, University of Nariño, San Juan de Pasto 52001, Colombia.
Quantitative Veterinary Epidemiology Group, Animal Sciences Department, Wageningen University and Research, 6702 PB Wageningen, The Netherlands.
Animals (Basel). 2022 Jul 5;12(13):1734. doi: 10.3390/ani12131734.
Bovine leukemia virus (BLV) is a retrovirus that affects cattle worldwide. A longitudinal study was conducted with the aim to (a) estimate the incidence rate of the BLV infection of dairy farms in the regions of Los Ríos and Los Lagos (Chile), and (b) describe the frequency and epidemiological association of risk management practices related to new cases in cattle on dairy farms in Southern Chile. Infection status was based on commercial blocking ELISA results, on serum and milk. Individual information on animals and management practices was extracted from farm records, and then the most likely date of infection for new cases was estimated. The number of new infections was used to calculate the within-herd incidence rate. Adult animals had an incidence rate of 1.16 (95% CI 0.96; 1.20) cases per 100 cow-months at risk, while for young animals it was 0.64 (95% CI 0.44; 1.00) cases per 100 animal-months at risk. Rectal palpation, artificial insemination, and injections were the most common practices related to infection. Further studies are needed to determine if these are the only practices that facilitate spreading or if there are other practices that can be handled better in order to reduce the spread of BLV.
牛白血病病毒（BLV）是一种影响全球牛群的逆转录病毒。开展了一项纵向研究，目的是：（a）估计洛斯里奥斯和洛斯拉戈斯地区（智利）奶牛场BLV感染的发病率，以及（b）描述智利南部奶牛场与牛群新发病例相关的风险管理措施的频率和流行病学关联。感染状况基于血清和牛奶的商业阻断ELISA结果。从农场记录中提取动物个体信息和管理措施，然后估计新发病例最可能的感染日期。用新感染病例数计算牛群内发病率。成年动物的发病率为每100个风险牛月1.16例（95%置信区间0.96；1.20），而幼龄动物为每100个风险动物月0.64例（95%置信区间0.44；1.00）。直肠检查、人工授精和注射是与感染相关的最常见操作。需要进一步研究以确定这些是否是促进传播的唯一操作，或者是否有其他可以更好处理的操作以减少BLV的传播。
