Laboratorio de Parasitología, Centro de Investigaciones Agrarias de Mabegondo, AGACAL, Abegondo, A Coruña, España.
Laboratorio de Parasitología, Facultad de Farmacia, Universidad de Santiago de Compostela, Santiago de Compostela, España.
PLoS One. 2022 Mar 24;17(3):e0265569. doi: 10.1371/journal.pone.0265569. eCollection 2022.
Fasciolosis is a severe zoonosis responsible for major economic losses in livestock. The enhanced MM3-COPRO test (eMM3-COPRO) and the commercial version BIO K 201 (Bio-X Diagnostics, Rochefort, Belgium) are widely used as immunodiagnostic tools for the specific detection of coproantigens released by Fasciola during the late prepatent and patent stages of infection. However, performance of the eMM3-COPRO has never been evaluated under field conditions. To address this gap, a large number of ovine faecal samples, collected in a region where fasciolosis is endemic (Galicia, NW Spain), were analyzed. Two groups of sheep flocks were selected according to the Fasciola infection status: 'Fasciola-free' and 'Fasciola-infected' flocks. 'Fasciola-free' flocks were seronegative flocks with no history of fasciolosis detected by either coproscopy or necropsy in the last 5 years. Faecal samples from these sheep were used to calculate a cut-off value for infection (OD = 0.021). The cut-off was calculated using a bootstrap resampling method that enables estimation of the sampling distribution of the statistical parameters without making assumptions about the underlying data distribution. 'Fasciola-infected' flocks were characterized by high seroprevalence, a history of fasciolosis and periodical treatment with flukicides. Samples from these flocks were used to estimate the diagnostic accuracy of the eMM3-COPRO relative to coproscopy, which although limited by poor sensitivity is the only reference test available for diagnosing fasciolosis in vivo. To overcome this limitation, all animals classified positive by eMM3-COPRO were treated with triclabendazole and then retested. The eMM3-COPRO displayed higher sensitivity than coproscopy, as it detected coproantigens in all samples with positive coproscopy and in 12% of samples with negative coproscopy. The test also proved highly specific as coproantigens disappeared after the treatment. The eMM3-COPRO was less time consuming than coproscopy, particularly when the procedure involved numerous samples, and showed promise as a tool for monitoring flukicide efficacy.
片形吸虫病是一种严重的人畜共患病，给畜牧业造成了重大经济损失。增强型 MM3-COPRO 检测（eMM3-COPRO）和商业化的 BIO K 201（罗氏诊断，罗什福尔，比利时）被广泛用作检测在感染的迟前期和无前期阶段由片形吸虫释放的粪抗原的免疫诊断工具。然而，eMM3-COPRO 的性能从未在野外条件下进行过评估。为了弥补这一空白，对在片形吸虫病流行地区（西班牙西北部加利西亚）采集的大量绵羊粪便样本进行了分析。根据片形吸虫感染状况选择了两组绵羊群：“无片形吸虫”和“感染片形吸虫”羊群。“无片形吸虫”羊群是血清阴性羊群，在过去 5 年中，无论是通过粪便检查还是剖检都没有发现片形吸虫感染。这些绵羊的粪便样本用于计算感染的截断值（OD = 0.021）。截断值是使用 bootstrap 重采样方法计算的，该方法无需对基础数据分布做出假设即可估计统计参数的抽样分布。“感染片形吸虫”羊群的特点是高血清阳性率、片形吸虫病史和定期使用驱虫剂治疗。这些羊群的样本用于估计 eMM3-COPRO 相对于粪便检查的诊断准确性，尽管粪便检查的敏感性有限，但它是目前唯一可用于体内诊断片形吸虫病的参考测试。为了克服这一局限性，所有通过 eMM3-COPRO 检测为阳性的动物都用三氯苯达唑进行了治疗，然后进行了重新检测。eMM3-COPRO 的敏感性高于粪便检查，因为它在所有粪便检查阳性的样本和 12%的粪便检查阴性的样本中都检测到了粪抗原。该检测也具有高度特异性，因为在治疗后粪抗原消失了。eMM3-COPRO 比粪便检查耗时更少，特别是在处理大量样本时，并且有望成为监测驱虫剂效果的工具。
