Macchi María V, Suanes Alejandra, Salaberry Ximena, Fernandez Federico, Piaggio José, Gil Andrés D
División de laboratorios Veterinarios, Ministerio de Ganadería, Agricultura y Pesca, Montevideo, Uruguay.
División de laboratorios Veterinarios, Ministerio de Ganadería, Agricultura y Pesca, Montevideo, Uruguay.
Prev Vet Med. 2020 Jun;179:105022. doi: 10.1016/j.prevetmed.2020.105022. Epub 2020 Apr 29.
Neosporosis is one of the leading causes of abortion in cattle worldwide, posing a great economic burden on cattle producers. The aim of this study was to determine the national seroprevalence and putative risk factors of Neospora caninum (N. caninum) in dairy cattle in Uruguay. A cross-sectional study was carried out. Herds were stratified by size (1-50, 51-250, and >250 cattle) and up to 60 dairy cows per herd were randomly selected. Four thousand two hundred twenty-three serum samples from 102 dairy herds were analyzed by indirect ELISA test, under the manufacturer's recommendations. In addition, the herdsman was surveyed and a population study was carried out. The in degree data, geographical coordinates, and seroprevalence of bovine viral diarrhea, enzootic bovine leukemia and infectious bovine rhinotracheitis were available for each herd. A sampling design was used to estimate population seroprevalence of N. caninum. In order to determine the factors associated with the disease, herds with an intra-herd seroprevalence over 20% were considered as case herds. Seroprevalence of N. caninum was 22.3% (95% CI: 18.7-25.9 %) and 96.0% (95% CI: 92.1-99.8%) at the animal and herd level, respectively. The number of dogs on the dairy farms were associated with infection levels (OR: 1.43, 95% CI: 1.02 to 2.03). It was concluded that N. caninum is endemic in the country, and is spreading over dairy herds. Although this study showed evidence that the number of dogs were associated with high levels of infection, more studies should be conducted, to better understand the epidemiology of the disease and thus develop efficient control measures.
新孢子虫病是全球范围内导致奶牛流产的主要原因之一，给奶牛养殖户带来了巨大的经济负担。本研究的目的是确定乌拉圭奶牛中犬新孢子虫的全国血清流行率及推定风险因素。开展了一项横断面研究。根据牛群规模（1 - 50头、51 - 250头和>250头）进行分层，每个牛群随机选取多达60头奶牛。按照制造商的建议，采用间接ELISA试验对来自102个奶牛群的4223份血清样本进行了分析。此外，对牧民进行了调查并开展了一项群体研究。每个牛群都有牛病毒性腹泻、地方流行性牛白血病和传染性牛鼻气管炎的入度数据、地理坐标及血清流行率。采用抽样设计来估计犬新孢子虫的群体血清流行率。为了确定与该疾病相关的因素，将牛群内血清流行率超过20%的牛群视为病例牛群。犬新孢子虫在动物和牛群水平的血清流行率分别为22.3%（95%置信区间：18.7 - 25.9%）和96.0%（95%置信区间：92.1 - 99.8%）。奶牛场中狗的数量与感染水平相关（比值比：1.43，95%置信区间：1.02至2.03）。得出的结论是，犬新孢子虫在该国呈地方流行性，且正在奶牛群中传播。尽管本研究表明有证据显示狗的数量与高感染水平相关，但仍应开展更多研究，以更好地了解该疾病的流行病学，从而制定有效的控制措施。
