Animal Disease Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Pullman, WA, USA; School of Veterinary Medicine, St. George's University, True Blue, Grenada, W. I..
Animal Disease Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Pullman, WA, USA.
Ticks Tick Borne Dis. 2018 Feb;9(2):135-140. doi: 10.1016/j.ttbdis.2017.08.007. Epub 2017 Aug 25.
Certain countries including the United States remain non-endemic for particular infectious diseases such as equine piroplasmosis through import restrictions and surveillance. Endemic regions often employ premunition as the primary method to control disease, however in non-endemic countries, chemosterilization combined with methods to confirm parasite elimination are required to maintain disease-free status. The ability of imidocarb diproprionate (ID) to clear persistent Theileria equi infection from infected horses has been shown through the inability of treated horses to transmit via blood transfer. However, the common lengthy persistence of anti-T. equi antibody causes regulatory tests such as cELISA or IFA to remain positive for extended periods. Persistence of positive testing creates challenges for regulatory veterinary medicine and international trade. Concordance between nested polymerase chain reaction (nPCR) targeting the ema1 gene and immunoblotting (IB) measuring declination in anti-EMA1 and anti-EMA2 antibody were used to verify clearance of T. equi from 179 ID-treated horses. These data support the use of IB to demonstrate declining anti-EMA1 and EMA2 titers in T. equi-infected horses subsequent to successful ID treatment. Such data provide concordant support to a negative nPCR and allow for a more timely determination of effective ID clearance of T. equi. The post ID treatment results indicate that while nPCR was consistently negative by 14 days and cELISA generally remained positive after 1 year, immunoblot was on average negative after 4 months and 100% in agreement with nPCR.
某些国家，包括美国，由于进口限制和监测，对某些传染病（如马梨形虫病）保持非地方性。地方性地区通常采用预防接种作为控制疾病的主要方法，但在非地方性国家，需要化学绝育与确认寄生虫消除的方法相结合，以维持无病状态。伊维菌素二丙酯（ID）能够清除感染马体内持续存在的马梨形虫感染，这一点已通过处理过的马通过血液转移无法传播来证明。然而，抗马梨形虫抗体的常见长时间持续存在导致监管测试（如 cELISA 或 IFA）在延长的时间内仍呈阳性。阳性检测的持续存在给监管兽医和国际贸易带来了挑战。针对 ema1 基因的巢式聚合酶链反应（nPCR）和免疫印迹（IB）测量抗 EMA1 和抗 EMA2 抗体下降的一致性，用于验证 179 匹 ID 处理过的马体内的 T. equi 已被清除。这些数据支持使用 IB 来证明 T. equi 感染马在成功接受 ID 治疗后，抗 EMA1 和 EMA2 滴度下降。这些数据为阴性 nPCR 提供了一致的支持，并允许更及时地确定 ID 对 T. equi 的有效清除。ID 治疗后的结果表明，虽然 nPCR 在 14 天内始终为阴性，cELISA 在 1 年后通常仍为阳性，但免疫印迹平均在 4 个月后为阴性，与 nPCR 完全一致。
