Relationship between the dissemination of small ruminant lentivirus infection in goat herds and opinion of farmers on the occurrence of arthritis

Small ruminant lentivirus (SRLV) infection manifests itself mainly with chronic progressive arthritis affecting mainly carpal joints. The data from serological and questionnaire surveys were retrospectively analyzed to determine how the dissemination of SRLV infection in the herd influenced farmer’s subjective opinion on the occurrence of swelling of carpal joints (considered as a proxy of arthritis). Between 1996 and 2017 153 different Polish dairy goat herds counting at least 20 adult goats were serologically screened for CAE and their owners were asked about their opinion on the occurrence of arthritis (never, rarely, often). Of them 73 SRLV-seropositive herds, in which true seroprevalence had been estimated, were included in the analysis. The ordinal logistic regression model was developed to determine the relationship between the true within-herd seroprevalence and the probability that the farmer would observe arthritis in the herd never, rarely or often. True within-herd seroprevalence ranged from 0.2% to 100% with the median of 34.6%. Farmers declared not to have observed arthritis in 40 (54.8%) herds, to have seen it rarely in 9 (12.3%) of herds, and to have observed it often in 24 (32.9%) of herds. The model proved that the probability of observing goats with carpal arthritis in the herd was significantly linked to the true within-herd seroprevalence (OR = 1.058, CI 95% from 1.037 to 1.078; p

小反刍兽慢病毒（Small ruminant lentivirus, SRLV）感染主要表现为慢性进行性关节炎，且主要累及腕关节。本研究通过回顾性分析血清学调查与问卷调查数据，旨在明确畜群中小反刍兽慢病毒感染的传播情况对养殖户主观判断腕关节肿胀（作为关节炎的替代指标）发生情况的影响。1996年至2017年间，研究团队对153个存栏成年山羊不少于20只的波兰乳用山羊群开展了山羊关节炎脑炎（Caprine Arthritis Encephalitis, CAE）血清学筛查，并向其养殖户询问关节炎发生情况的主观判断（分为从未、偶尔、经常三类）。其中，73份SRLV血清学阳性的畜群（已估算出真实血清阳性率）被纳入本分析。本研究构建了有序logistic回归模型，以探究畜群内真实血清阳性率与养殖户判断畜群关节炎发生情况为从未、偶尔或经常的概率之间的关联。本次分析涉及的畜群内真实血清阳性率范围为0.2%至100%，中位数为34.6%。养殖户反馈称，40个（54.8%）畜群从未出现关节炎、9个（12.3%）偶尔出现、24个（32.9%）经常出现。模型结果显示，畜群内出现腕关节感染山羊的概率与真实群内血清阳性率存在显著关联（优势比OR=1.058，95%置信区间CI为1.037~1.078；P