Rinaldi L, Fusco G, Musella V, Veneziano V, Guarino A, Taddei R, Cringoli G
Dipartimento di Patologia e Sanità Animale, Facoltà di Medicina Veterinaria, Università degli Studi di Napoli Federico II, CREMOPAR Regione Campania, Via della Veterinaria 1, 80137 Napoli, Italy.
Vet Parasitol. 2005 Mar 31;128(3-4):219-30. doi: 10.1016/j.vetpar.2004.12.011. Epub 2005 Jan 26.
A cross-sectional serological survey was conducted on cattle pasturing in an area of the southern Italian Apennines to evaluate the seroprevalence to Neospora caninum, and to investigate the climatic, environmental, farm management, and individual animal factors that influence the distribution of this protozoan. Blood samples were collected from 864 pastured cattle raised on 81 farms. Serum samples were tested for antibodies to N. caninum using an ELISA assay (HerdCheck), IDEXX). A geographical information system (GIS) for the study area was constructed using the following remote sensing (RS) and landscape feature data: autumn-winter, spring and summer normalized difference vegetation index (NDVI), land cover, elevation, slope, aspect, mean rainfall and minimum, mean, and maximum temperature in spring, summer, autumn and winter. Data on each of these features were then extracted for "buffer zones" consisting of the area included in a circle of 3 km diameter centered on the 81 geo-referenced centroids of the main cattle pastures. Climatic and environmental data obtained from RS and GIS and individual animal characteristics and farm management data obtained from a questionnaire were analyzed in relation to N. caninum seropositivity and antibody titres both by linear and logistic regression models. Out of the 81 farms sampled, 63 (77.8%) had at least one tested animal positive for N. caninum. Out of the 864 bovine sera samples, 266 (30.8%) were found to have antibodies to N. caninum. The results of the logistic regression model show that significantly high seroprevalence to N. caninum was found in heifers/steers and adults, in cattle raised on farms having a large number of dogs, and in cattle raised in buffer zones having high minimum temperatures in the spring, and a narrow extension of summer NDVI. In addition, positive linear correlations were found between N. caninum antibody titres and the number of dogs on farm, and the minimum temperature in spring. All the above determined risk factors for N. caninum seroprevalence indicate that horizontal infection resulting from the ingestion of oocysts shed by dogs is the most probable route of N. caninum infection in pastured cattle of the southern Italian Apennines.
在意大利亚平宁山脉南部某地区对放牧牛群进行了一项横断面血清学调查，以评估犬新孢子虫的血清阳性率，并调查影响这种原生动物分布的气候、环境、农场管理和个体动物因素。从81个农场饲养的864头放牧牛中采集血样。使用酶联免疫吸附测定法（HerdCheck，IDEXX）检测血清样本中犬新孢子虫抗体。利用以下遥感（RS）和景观特征数据构建研究区域的地理信息系统（GIS）：秋冬、春夏归一化植被指数（NDVI）、土地覆盖、海拔、坡度、坡向、平均降雨量以及春、夏、秋、冬的最低、平均和最高温度。然后针对以81个主要牛牧场地理参考中心为圆心、直径3公里的圆所包含区域组成的“缓冲区”，提取上述各特征的数据。通过线性和逻辑回归模型，分析从RS和GIS获得的气候与环境数据以及从问卷中获得的个体动物特征和农场管理数据与犬新孢子虫血清阳性和抗体滴度之间的关系。在抽样的81个农场中，63个（77.8%）至少有一头检测动物犬新孢子虫呈阳性。在864份牛血清样本中，266份（30.8%）被发现含有犬新孢子虫抗体。逻辑回归模型结果表明，在小母牛/阉牛和成年牛中，在养狗数量多的农场饲养的牛中，以及在春季最低温度高且夏季NDVI范围窄的缓冲区饲养的牛中，犬新孢子虫血清阳性率显著较高。此外，犬新孢子虫抗体滴度与农场犬只数量以及春季最低温度之间存在正线性相关。上述所有确定的犬新孢子虫血清阳性风险因素表明，摄入犬排出的卵囊导致的水平感染是意大利亚平宁山脉南部放牧牛感染犬新孢子虫最可能的途径。
