Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy.
CDVet Research, Laboratorio Analisi Veterinarie, Via Giovanni Nicotera 7, Roma 00195, Italy.
Vet Parasitol. 2024 Jul;329:110192. doi: 10.1016/j.vetpar.2024.110192. Epub 2024 May 4.
Giardia duodenalis (syn. G. intestinalis or G. lamblia) is a parasitic protozoan that infects the upper intestinal tract of a broad range of hosts, including humans and domestic animals. Thus, it has raised concerns about the public health risk due to companion animals. Recently, with the improvement of living standards and increasing contacts between pets and humans, the zoonotic transmission of Giardia has dramatically increased. From a genetic point of view, G. duodenalis should be viewed as a complex species that includes eight different species-specific genetic assemblages. The laboratory diagnosis is mainly based on the finding of microscopic cysts in stool samples by coprological examination. Other methods include the detection of antigens, immunoassays or PCR protocols, which allow the identification of Giardia assemblages. The study aimed to compare the performance of Direct Fluorescence Antibody test (DFA), zinc sulfate flotation technique (ZnSO4), rapid diagnostic test (RDT), end-point PCR amplification (PCR) for the detection of Giardia and to identify the concerning assemblages in a canine population from Central Italy. Direct fluorescence antibody test is the reference standard for laboratory diagnosis of Giardia in fecal samples from dogs, despite the microscopic examination after flotation remains the most useful method in many veterinary diagnostic centers. The present findings demonstrate the high performance of DFA and ZnSO4 in detecting Giardia, while RDT may be useful as alternative or complementary method to the DFA and ZnSO4. PCR performance was low, but it allowed determining Giardia B zoonotic assemblage in 25% of the PCR-positive specimens (15 out of 60), while the remaining PCR-positive isolates belonged to the dog-specific assemblage C. The 26% prevalence of G. duodenalis detected by DFA in owned dogs and the identification of potentially zoonotic assemblages underline the potential risk for public health and indicate frequent cross-species transmission of the parasite between humans and dogs.
十二指肠贾第鞭毛虫（同义词：G. 肠内或 G. 蓝氏贾第鞭毛虫）是一种寄生的原生动物，感染范围广泛的宿主的上消化道，包括人类和家畜。因此，它引起了人们对伴侣动物公共卫生风险的关注。最近，随着生活水平的提高和宠物与人类之间的接触越来越多，贾第鞭毛虫的人畜共患病传播显著增加。从遗传角度来看，G. 十二指肠应该被视为一个复杂的物种，包括 8 个不同的种特异性遗传组合。实验室诊断主要基于粪便样本中通过粪便检查发现微观囊肿。其他方法包括检测抗原、免疫测定或 PCR 方案，这些方法允许鉴定贾第鞭毛虫组合。本研究旨在比较直接荧光抗体试验（DFA）、硫酸锌浮选技术（ZnSO4）、快速诊断试验（RDT）、终点 PCR 扩增（PCR）在检测犬肠道寄生虫中的性能，并鉴定意大利中部犬种群中的相关组合。直接荧光抗体试验是犬粪便样本中贾第鞭毛虫实验室诊断的参考标准，尽管浮选后的显微镜检查仍然是许多兽医诊断中心最有用的方法。本研究结果表明 DFA 和 ZnSO4 在检测贾第鞭毛虫方面具有较高的性能，而 RDT 可能是 DFA 和 ZnSO4 的替代或补充方法。PCR 性能较低，但它允许在 25%的 PCR 阳性标本（60 份中的 15 份）中确定 B 种贾第鞭毛虫的致病变种，而其余的 PCR 阳性分离物属于犬特异性组合 C。DFA 在犬科动物中检测到的 26%的 G. 十二指肠鞭毛虫的流行率和潜在的致病变种的鉴定强调了公共卫生的潜在风险，并表明寄生虫在人类和犬科动物之间经常发生跨物种传播。
