Infectious Diseases Unit, Maimonides Institute for Biomedical Research (IMIBIC), University Hospital Reina Sofía, Córdoba, University of Córdoba, Córdoba, Spain.
Parasitology Reference and Research Laboratory, Spanish National Centre for Microbiology, Majadahonda, Madrid, Spain.
Parasit Vectors. 2020 Jun 3;13(1):281. doi: 10.1186/s13071-020-04152-9.
Several studies have independently evaluated the occurrence of hepatitis E virus (HEV) and enteroparasites in swine, but no surveys have been conducted to jointly assess the prevalence and genetic diversity of enteroparasites in pigs and wild boars, their sympatric transmission between hosts, and their potential interaction with HEV.
We prospectively collected serum and faecal samples from black Iberian domestic pigs and wild boars from southern Spain between 2015‒2016. We evaluated for HEV in serum and faeces, and for the presence of enteroparasites (Giardia duodenalis, Cryptosporidium spp., Blastocystis sp., Neobalantidium coli and Strongyloides spp.) in the same faecal samples. The prevalence of each intestinal parasite species was calculated.
A total of 328 animals (56.7% black Iberian pigs and 43.3% wild boars) were included in the study. The overall global prevalence of HEV in serum was 16.8%. The overall global prevalence of each enteroparasite species was 19.5% for G. duodenalis, 8.2% for Cryptosporidium spp., 41.8% for Blastocystis sp., 31.4% for N. coli, and 8.8% for Strongyloides spp. HEV-infected animals showed a significantly lower prevalence of G. duodenalis (3.2 vs 20%; P = 0.002) and Blastocystis sp. (38.7 vs 80%; P < 0.001) than those uninfected by HEV. Animals carrying G. duodenalis and Blastocystis sp. infections showed a significantly lower rate of HEV infection than those not harbouring these enteroparasites (P < 0.001).
Our study found a high prevalence of enteroparasites in black Iberian pigs and wild boars in southern Spain, suggesting a sympatric co-transmission of some of the species investigated. It is suggested that extracellular G. duodenalis and Blastocystis sp. might have a protective effect on HEV acquisition in swine.
已有多项研究分别评估了戊型肝炎病毒（HEV）和肠道寄生虫在猪群中的流行情况，但目前尚未有研究联合评估猪和野猪中肠道寄生虫的流行率和遗传多样性、宿主间的共生传播及其与 HEV 的潜在相互作用。
我们于 2015 年至 2016 年期间前瞻性地采集了来自西班牙南部的黑色伊比利亚家猪和野猪的血清和粪便样本。我们评估了血清和粪便中的 HEV 以及粪便中肠道寄生虫（十二指肠贾第鞭毛虫、隐孢子虫、蓝氏贾第鞭毛虫、结肠小袋纤毛虫和类圆线虫）的存在情况。计算了每种肠道寄生虫的流行率。
共纳入 328 只动物（56.7%为黑色伊比利亚猪，43.3%为野猪）。血清中 HEV 的总体全球流行率为 16.8%。每种肠道寄生虫的总体全球流行率分别为：十二指肠贾第鞭毛虫 19.5%、隐孢子虫 8.2%、蓝氏贾第鞭毛虫 41.8%、结肠小袋纤毛虫 31.4%和类圆线虫 8.8%。HEV 感染动物的十二指肠贾第鞭毛虫（3.2%比 20%；P=0.002）和蓝氏贾第鞭毛虫（38.7%比 80%；P<0.001）的流行率明显低于未感染 HEV 的动物。携带十二指肠贾第鞭毛虫和蓝氏贾第鞭毛虫感染的动物的 HEV 感染率明显低于未携带这些肠道寄生虫的动物（P<0.001）。
本研究在西班牙南部的黑色伊比利亚猪和野猪中发现了肠道寄生虫的高流行率，提示一些调查的物种存在共生共传播。推测细胞外的十二指肠贾第鞭毛虫和蓝氏贾第鞭毛虫可能对猪群中 HEV 的获得具有保护作用。
