Department of Health Management Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave., Charlottetown, PE, C1A 4P3, Canada.
Vet Parasitol. 2012 Feb 28;184(1):18-24. doi: 10.1016/j.vetpar.2011.07.047. Epub 2011 Aug 4.
In a cross-sectional study of 633 pigs from 21 herds on Prince Edward Island, Canada (PEI), the prevalence of infection with Cryptosporidium and Giardia, and the genotypes and species of isolates were determined in order to establish the zoonotic potential of pigs in this region. As determined by direct immunofluorescence microscopy (DFA), 18 herds (86%) and 163 animals (26%; 95% CI: 22-29%) tested positive for Cryptosporidium, while just 3 herds (14%) and 6 animals (1%; 95% CI: 0.4-2%) tested positive for Giardia. Cryptosporidium spp. isolates were detected in 39% (95% CI: 34-44%) of weanlings (1-3 months of age) and 9% (95% CI: 6-13) of sows (>8months of age). Molecular characterization using the 18S rDNA and HSP70 gene fragments revealed the presence of Cryptosporidium sp. pig genotype II, C. suis, C. parvum, and Cryptosporidium sp. mouse genotype. Among the 113 isolates of Cryptosporidium spp. successfully genotyped, pig genotype II (61%) predominated, with C. suis (36%) being the next most prominant isolate. C. parvum (2%; two isolates) and Cryptosporidium sp. mouse genotype (0.9%; one isolate) were only occasionally isolated. The only two Cryptosporidium-positive genotyped isolates from sows included one each of C. suis and Cryptosporidium sp. pig genotype II. All but one of the six Giardia positive isolates were detected in weanling pigs. None of the Giardia-positive isolates was amenable to PCR. This study demonstrates that Cryptosporidium spp. are highly prevalent in pigs on PEI, Canada, are found mostly in weanlings (1-3 months of age). Furthermore, the pigs are primarily infected by the host-specific genotypes and species, Cryptosporidium sp. pig genotype II and C. suis, whereas the zoonotic C. parvum is rare. Giardia duodenalis is only occasionally found in pigs. These findings suggest that domestic pigs on PEI, Canada, likely do not pose a significant health risk to humans from these parasites.
在对加拿大爱德华王子岛（PEI）的 21 个猪群中的 633 头猪进行的横断面研究中，确定了隐孢子虫和贾第鞭毛虫的感染率，以及分离株的基因型和物种，以确定该地区猪的人畜共患病潜力。通过直接免疫荧光显微镜检查（DFA），18 个猪群（86%）和 163 头动物（26%；95%置信区间：22-29%）检测出隐孢子虫阳性，而只有 3 个猪群（14%）和 6 头动物（1%；95%置信区间：0.4-2%）检测出贾第鞭毛虫阳性。在 1-3 个月龄的断奶仔猪（39%；95%置信区间：34-44%）和 >8 月龄的母猪（9%；95%置信区间：6-13%）中检测到隐孢子虫 spp.分离株。使用 18S rDNA 和 HSP70 基因片段进行分子特征分析表明，存在猪隐孢子虫基因型 II、C. suis、C. parvum 和鼠隐孢子虫基因型。在成功分型的 113 株隐孢子虫分离株中，猪基因型 II（61%）占优势，其次是 C. suis（36%）。仅偶尔分离到 C. parvum（2%；两株）和鼠隐孢子虫基因型（0.9%；一株）。来自母猪的两种隐孢子虫阳性分型分离株中，各有一株为 C. suis 和猪隐孢子虫基因型 II。6 头断奶仔猪中有 5 头检测到贾第鞭毛虫阳性，但只有 1 头分离到贾第鞭毛虫。PCR 不适用于所有 6 株贾第鞭毛虫阳性分离株。本研究表明，在加拿大爱德华王子岛的猪中，隐孢子虫高度流行，主要发生在断奶仔猪（1-3 个月龄）。此外，猪主要感染宿主特异性基因型和物种，即猪隐孢子虫基因型 II 和 C. suis，而罕见的人源隐孢子虫 C. parvum。仅偶尔在猪中发现十二指肠贾第鞭毛虫。这些发现表明，加拿大爱德华王子岛的家猪不太可能对人类构成这些寄生虫的重大健康风险。
