Villa-Mancera A, Reynoso-Palomar A
Facultad de Medicina Veterinaria y Zootecnia, Benemérita Universidad Autónoma de Puebla, 4 Sur 304 Col. Centro, CP 75482, Tecamachalco Puebla, México.
J Helminthol. 2019 Nov;93(6):704-710. doi: 10.1017/S0022149X18000792. Epub 2018 Sep 4.
Fasciola hepatica is a helminth parasite that causes huge economic losses to the livestock industry worldwide. Fasciolosis is an emerging foodborne zoonotic disease that affects both humans and grazing animals. This study investigated the associations between climatic/environmental factors (derived from satellite data) and management factors affecting the spatial distribution of this liver fluke in cattle herds across different climate zones in three Mexican states. A bulk-tank milk (BTM) IgG1 enzyme-linked immunosorbent assay (ELISA) test was used to detect F. hepatica infection levels of 717 cattle herds between January and April 2015. Management data were collected from the farms by questionnaire. The parasite's overall herd prevalence and mean optical density ratio (ODR) were 62.76% and 0.67, respectively. The presence of clustered F. hepatica infections was studied using the spatial scan statistic. Three marked clusters in the spatial distribution of the parasite were observed. Logistic regression was used to test three models of potential statistical association from the ELISA results using climatic, environmental and management variables. The final model based on climatic/environmental and management variables included the following factors: rainfall, elevation, proportion of grazed grass in the diet, contact with other herds, herd size, parasite control use and education level as significant predictors. Geostatistical kriging was applied to generate a risk map for the presence of parasites in dairy herds in Mexico. In conclusion, the spatial distribution of F. hepatica in Mexican cattle herds is influenced by multifactorial effects and should be considered in developing regionally adapted control measures.
肝片吸虫是一种蠕虫寄生虫，给全球畜牧业造成巨大经济损失。肝片吸虫病是一种新出现的食源性人畜共患病，会影响人类和放牧动物。本研究调查了气候/环境因素（源自卫星数据）与管理因素之间的关联，这些因素影响着墨西哥三个州不同气候区牛群中这种肝吸虫的空间分布。采用大容量罐牛奶（BTM）IgG1酶联免疫吸附测定（ELISA）试验，检测了2015年1月至4月间717个牛群的肝片吸虫感染水平。通过问卷调查从农场收集管理数据。该寄生虫在牛群中的总体患病率和平均光密度比值（ODR）分别为62.76%和0.67。使用空间扫描统计量研究了肝片吸虫感染的聚集情况。观察到该寄生虫空间分布中的三个显著聚集区。使用气候、环境和管理变量，通过逻辑回归对ELISA结果的三种潜在统计关联模型进行了检验。基于气候/环境和管理变量的最终模型纳入了以下因素：降雨量、海拔、日粮中放牧草的比例、与其他牛群的接触、牛群规模、寄生虫控制措施的使用以及教育水平，作为显著预测因素。应用地质统计学克里金法生成了墨西哥奶牛群中寄生虫存在情况的风险图。总之，墨西哥牛群中肝片吸虫的空间分布受多因素影响，在制定区域适应性控制措施时应予以考虑。
