Epidemiologic analysis of Leptospira spp. infection among sheep in Pernambuco state, Brazil

ABSTRACT: This study aimed to analyze epidemiological aspects and spatial characteristics of Lesptospira spp. infection among sheep in Pernambuco state, Brazil. A total of 426 samples were collected from unvaccinated animals aged 1 year or older, and submitted to Microscopic Agglutination Test (MAT). To study the risk factors, a standardized investigative survey of sheep farmers, with objective questions, was conducted to establish the general characteristics of the farm property production, reproductive management, and health plan. From 426 samples analyzed, 83 (19.5%; CI 15.9 - 23.6%) were positive; among them, the most prevalent serovar was Autumnalis (32.4%). Significant differences were observed between gender (OR = 0.38; CI 0.14 - 0.99), production system (OR = 2.03; CI 1.07 - 3.84), types of herd (OR = 2.28; CI 1.39 - 3.72), absence of rodents to the grain storage (OR = 0.55; CI 0.34 - 0.91), and restriction to surface waters (OR = 0.60; CI 0.37 - 0.99). Leptospira spp. infection is disseminated in sheep herds, and multiple factors can influence its occurrence. Health education programs and worker training in prevention and control of leptospirosis and other infectious diseases may be useful to reduce infection rates and economic losses caused by this disease.

摘要：本研究旨在分析巴西伯南布哥州绵羊感染钩端螺旋体属（Leptospira spp.）的流行病学特征与空间分布特征。研究共采集426份1岁及以上未接种疫苗的绵羊样本，采用显微凝集试验（Microscopic Agglutination Test，MAT）开展检测。为明确感染危险因素，本研究通过设置客观题的标准化养殖户问卷调查，采集了养殖场生产概况、繁殖管理及卫生防疫方案等相关信息。在426份检测样本中，共计83份呈阳性，阳性率为19.5%（置信区间（Confidence Interval，CI）：15.9%~23.6%）；其中检出率最高的血清型为秋季型（Autumnalis），占阳性样本的32.4%。分析显示，性别（比值比（Odds Ratio，OR）=0.38；置信区间CI：0.14~0.99）、养殖生产模式（OR=2.03；CI：1.07~3.84）、畜群类型（OR=2.28；CI：1.39~3.72）、粮库无鼠患（OR=0.55；CI：0.34~0.91）以及限制使用地表水（OR=0.60；CI：0.37~0.99）等因素与绵羊钩端螺旋体属感染存在显著关联。钩端螺旋体属感染在绵羊畜群中广泛传播，多种因素可影响其感染发生。开展针对钩端螺旋体病（Leptospirosis）及其他传染病的防控健康教育与从业人员培训项目，有助于降低该疾病的感染率及由此造成的经济损失。