Seroprevalence and risk factors of bovine leptospirosis in the province of Manabí, Ecuador

Leptospirosis is a zoonotic disease with worldwide distribution. The disease affects dairy and beef cattle, causing infertility, abortion, and reduced milk yield. A cross-sectional study was conducted to determine the seroprevalence of leptospirosis in cattle and the associated risk factors in the province of Manabí, Ecuador. Serum samples from 749 animals from 55 cattle herds were analyzed using the microscopic agglutination test (MAT). Animals were considered positive when titers were ≥ 1:100. The association between the potential risk factors and the positive Leptospira result was modeled at both animal and herd level using a generalized linear model with a binomial distribution and logarithmic link. The seroprevalence was 56.21% at the individual level and 98.18% at the herd level. The most prevalent serovars were Pomona (28.57%) and Icterohaemorragiae (22.30%). At the animal level, only the age was associated with leptospirosis seropositivity. Seroprevalence in animals over three years of age was 1.197 (95% confidence intervals (CI), 1.032 – 1.390), higher compared to animals up to three years old. The seroprevalence of Leptospira spp. was higher in farms with no veterinary assistance (PR = 1.209; 95%CI 1.053 – 1.388) and without a vaccination program against Leptospira (PR = 1.399; 95%CI 1.09 - 1.794). In addition, herds from Junín canton had a significantly higher seroprevalence of Leptospira spp (PR = 1.548; 95%CI 1.213 - 1.977) compared to the Bolívar canton, which had the lowest seroprevalence. In conclusion, more than half of the animals were positive to Leptospiraspp, and almost all herds had at least one positive animal. Furthermore, veterinary assistance and vaccination of cattle must be considered as essential aspects of the disease control program.     

辽宁省某市奶牛布病感染状况及群间传播风险因素调查

为了解辽宁省某市的奶牛布鲁氏菌病（简称奶牛布病）流行现状及该市奶牛布病群间传播风险因素,开展本研究。对该市辖区内所有奶牛进行布鲁氏菌病的普查,获知该市奶牛布病的表观个体血清流行率和表观群血清流行率;采用问卷调查方式进一步开展病例-对照研究,初步筛选出14项该市奶牛布病群间传播可能风险因素,经相关性检验结合生物学知识,选取了5个变量进入多因素分析,最终通过非条件logistic回归方法初步建立了该市奶牛布病群间传播风险因素回归模型,并建立ROC曲线计算了模型的预测概率。研究结果显示,该市奶牛个体流行率为0.99%,群流行率12.44%。非条件logistic回归分析结果显示,该市奶牛布病群间传播的风险因素包括：“无专用购销车辆”（OR=3.57,95%CI：1.04-12.5,p =0.04）,“进圈时不穿专用工作服和胶靴”（OR=5.0,95%CI：0.97-25.00,p =0.06）,“与犬混养”（OR=12.39,95%CI：0.97-157.56,p=0.05）。该结果表明与犬混养可能是该市奶牛布病群间传播重要的风险因素,而奶牛销售时自有购销专用车辆和场内生物安全措施的采取如进圈穿专用工作服可使奶牛布病在场群间传播的风险降低。针对回归模型建立的ROC曲线下面积为71.6%,表明此模型解释该市奶牛布病群间传播风险的能力为中等。     

宁夏彭阳县肉牛布鲁氏菌病空间分析

为描述宁夏彭阳县肉牛布鲁氏菌病场户表观流行率空间分布模式,探究肉牛布鲁氏菌病高风险区域及其影响因素,基于彭阳县2021年3月开展的肉牛布鲁氏菌病横断面调查结果,应用地理信息系统(ArcGIS)软件进行全局空间自相关和局部空间自相关分析,使用SaTscan软件分析肉牛布鲁氏菌病高风险区域和空间聚集性,用GeoDetector探测其空间分布异质性影响因素。结果显示:在全局自相关分析中,全局莫兰指数(Global Moran's I)为正值(P<0.001),说明彭阳县不同感染程度的肉牛养殖场户呈现了明显的聚类特征;在局部自相关分析中,高值(H-H)聚集区主要集中在白阳镇、红河镇和冯庄乡,热点分析也显示出较为一致的结果;在空间聚集性分析中,彭阳县肉牛布病存在3个高风险地理聚集区(P<0.05),分别位于白阳镇、红河镇和冯庄乡;GeoDetector探测显示,乡镇肉牛存栏量、养牛场户离主要交通公路距离和周围养牛场户数影响肉牛布鲁氏菌病的空间分布异质性。结果表明,彭阳县肉牛布鲁氏菌病存在不同程度的聚集性,主要聚集在白阳镇、红河镇和冯庄乡。结果提示,应采取相应措施加大对较高风险区域乡镇的肉牛布鲁氏菌病控制,同时要加强对其他乡镇的肉牛布鲁氏菌病监测。     

Prevalence of Mastitis and Brucellosis in Cattle in Awassa and the Peri‐Urban Areas of Two Smaller Towns

The prevalence of mastitis and brucellosis in urban and peri‐urban settings was studied in Awassa and two smaller nearby towns in southern Ethiopia, because milk‐born diseases are causing a risk for human health, besides direct impacts on animal production. Mastitis was investigated by examining 80 cows (320 udder quarters) using California mastitis test (CMT) and somatic cell count (SCC). The prevalence of brucellosis was assessed by sampling 177 cattle in Awassa and its peri‐urban areas using serological methods. Logistic regression was used to analyse risk factors associated with mastitis. Prevalence of clinical mastitis on quarter level was 0.9%, and 1.9% of quarters were non‐functional or blocked. Prevalence of sub‐clinical mastitis at quarter level in urban and peri‐urban areas was significantly different (P < 0.05). Cows in large herds and at advanced lactation number were associated with higher risk of infection. The percentage of quarters positive on CMT (42.5%) was close to the percentage‐positive detected by SCC (41.2%). Prevalence of brucellosis was 3.9% in the peri‐urban area, while no brucellosis cases were detected in Awassa. More frequent use of artificial insemination in the urban than in peri‐urban area might have contributed to the absence of brucellosis in the urban location. The extent of mastitis is, however, a threat to the dairy enterprise in and around Awassa. Pasteurization of milk and milk products is indicated in some parts of the area because of the danger of brucellosis.     

黑龙江省某镇肉牛布鲁氏菌感染情况调查

为了解黑龙江省B镇肉牛的布鲁氏菌病流行现状,从而评估该病在当地牛群中的流行状况及人感染布鲁氏菌的风险,本研究以估计个体及群流行率为目的,按照预期流行率0.5%,可接受误差0.3%,置信水平95%对B镇531个肉牛养殖场户养殖的3535头肉牛进行随机抽样,获得血清样本1334份,用虎红平板凝集试验和试管凝集试验两种方法检测均为阳性的牛即为布病患病牛,同时对养殖户就养殖模式、动物来源、更新方式、既往病史、养殖规模等方面进行问卷调查。血清检测结果显示,虎红平板凝集5份阳性,阳性率为0.37%,对5份阳性血清进行试管凝集试验复检,布鲁氏菌抗体全部为阴性。同时回收问卷531份,有效问卷389份,合格率73.3%。根据本次检测结果,B镇肉牛布病个体流行率接近于零,牛群中没有发现利于布鲁氏菌感染的风险因素。     

肉牛布鲁氏杆菌病防控存在问题及努力方向

布鲁氏菌病是由布鲁氏菌引起的一种急性或慢人畜共患传染病,该病除了导致养牛企业直接经济损失外,还可能发生严重食品安全问题和因人被感染导致的严重公共卫生安全问题.多年来,各级动物防疫部门主要关注奶牛的布病防控,对肉牛的布病防控介入很少,造成肉牛布病感染情况不明、底子不清,防控力度不够.随着规模化肉牛养殖业的不断兴起,肉牛布...     

人畜间布鲁氏菌病研究进展

布鲁氏菌病(brucellosis,简称布病)呈世界性流行,全球有超过170个国家有布病报告。20世纪90年代中后期布病呈回升趋势,进入21世纪后疫情更加严峻;感染途径由主要的职业接触感染扩展到非职业的食源性感染,发病区域由北方牧区逐步向周边的半农半牧区和农区扩散,并向南方传播扩散。大多数患者通过直接或间接接触受感染的动物或动物产品感染,大多数动物感染是从患病动物、受污染的饲料和饮水点摄入病原体所致。目前,布病检测方法较多且各有其特点,其中细菌分离培养是\"金标准\",补体结合试验(CFT)是OIE公认的确诊试验。疫苗免疫是布病最为有效的控制措施,但目前尚未有国际认可的用于人的布病疫苗,动物疫苗也存在安全性差、免疫期短等多种缺陷。未来需要加强布病监测并制定有效的防治措施,开展多学科、多部门、多领域的携手合作,共同推动布病的预警、监督和防控。     

我国部分地区牛羊弓形虫血清流行病学调查

为了解我国牛羊弓形虫病流行情况,应用间接血凝试验（IHA）对河南、山东、山西、内蒙古、云南、贵州6省区151份牛血清、50份奶样、490份羊血清进行了弓形虫病血清流行病学调查。结果显示：151份被检牛血清和50份牛奶样品,弓形虫抗体均为阴性。490份羊血清弓形虫抗体总阳性率5.71％,其中母羊、公羊血清阳性率分别为4.03％和9.79％;山羊、绵羊、杂交羊血清阳性率分别为6.58％、4.81％和5.13％;阳性率最高的为公山羊（13.2％）,最低的为母绵羊（2.96％）。28份阳性羊血清中,75％的抗体滴度为1：64,25％的抗体滴度为1：256。1岁后的羊,随年龄增长,血清阳性率升高。     

Salmonella and on-farm risk factors in healthy slaughter-age cattle and sheep in eastern Australia

OBJECTIVE: To examine healthy slaughter-age cattle and sheep on-farm for the excretion of Salmonella serovars in faeces and to identify possible risk factors using a questionnaire. PROCEDURE: The study involved 215 herds and flocks in the four eastern states of Australia, 56 with prior history of salmonellosis. Production systems examined included pasture beef cattle, feedlot beef cattle, dairy cattle, prime lambs and mutton sheep and animals were all at slaughter age. From each herd or flock, 25 animals were sampled and the samples pooled for Salmonella culture. All Salmonella isolated were serotyped and any Salmonella Typhimurium isolates were phage typed. Questionnaires on each production system, prepared in Epi Info 6.04, were designed to identify risk factors associated with Salmonella spp excretion, with separate questionnaires designed for each production system. RESULTS: Salmonellae were identified in all production systems and were more commonly isolated from dairies and beef feedlots than other systems. Statistical analysis revealed that dairy cattle were significantly more likely to shed Salmonella in faeces than pasture beef cattle, mutton sheep and prime lambs (P<0.05). A wide diversity of Salmonella serovars, all of which have been isolated from humans in Australia, was identified in both cattle and sheep. Analysis of the questionnaires showed access to new arrivals was a significant risk factor for Salmonella excretion on dairy properties. For beef feedlots, the presence of large numbers of flies in the feedlot pens or around stored manure were significant risk factors for Salmonella excretion. CONCLUSION: Dairy cattle pose the highest risk of all the slaughter-age animals tested. Some of the identified risk factors can be overcome by improved management practices, especially in relation to hygiene.