Abstract:
In populations of healthy show horses, the subclinical transmission and circulation of respiratory pathogens can lead to disease outbreaks. Due to recent outbreaks of equine herpesvirus-1 myeloencephalopathy (EHM) in the USA and Europe, many show organizers have instituted various biosecurity protocols such as individual horse testing, monitoring for early clinical disease and increasing hygiene and cleanliness protocols. The aim of this study was to determine the accuracy of detecting EHV-1 in the various environmental samples collected from the stalls of subclinical shedders. Four healthy adult horses were vaccinated intranasally with a modified-live EHV-1 vaccine in order to mimic subclinical shedding. Three additional horses served as non-vaccinated controls. All the horses were stabled in the same barn in individual stalls. Each vaccinated horse had nose-to-nose contact with at least one other horse. Prior to the vaccine administration, and daily thereafter for 10 days, various samples were collected, including a 6\" rayon-tipped nasal swab, an environmental sponge, a cloth strip placed above the automatic waterer and an air sample. The various samples were processed for nucleic acid purification and analyzed for the presence of EHV-1 via quantitative PCR (qPCR). EHV-1 in nasal secretions was only detected in the vaccinated horses for 1-2 days post-vaccine administration. The environmental sponges tested EHV-1 qPCR-positive for 2-5 days (median 3.5 days) in the vaccinated horses and 1 day for a single control horse. EHV-1 was detected by qPCR in stall strips from three out of four vaccinated horses and from two out of three controls for only one day. EHV-1 qPCR-positive air samples were only detected in three out of four vaccinated horses for one single day. For the vaccinated horses, a total of 25% of the nasal swabs, 35% of the environmental stall sponges, 7.5% of the strips and 7.5% of the air samples tested qPCR positive for EHV-1 during the 10 study days. When monitoring the subclinical EHV-1 shedders, the collection and testing of the environmental sponges were able to detect EHV-1 in the environment with greater frequency as compared to nasal swabs, stationary strips and air samples.
摘要:
在健康的表演马群中,呼吸道病原体的亚临床传播和循环可导致疾病爆发。由于最近在美国和欧洲爆发了马疱疹病毒1型脊髓脑病(EHM),许多展览组织者已经制定了各种生物安全协议,例如个人马测试,监测早期临床疾病和增加卫生和清洁协议。这项研究的目的是确定从亚临床脱落器摊位收集的各种环境样品中检测EHV-1的准确性。用改良的活EHV-1疫苗鼻内接种四匹健康成年马,以模拟亚临床脱落。另外三匹马作为未接种疫苗的对照。所有的马都被稳定在同一个谷仓里的各个摊位。每一匹接种疫苗的马都与至少一匹其他马进行鼻对鼻接触。在接种疫苗之前,此后每天持续10天,收集了各种样本,包括一个6英寸的人造丝尖鼻拭子,环保海绵,放置在自动饮水机上方的布条和空气样品。处理各种样品用于核酸纯化,并通过定量PCR(qPCR)分析EHV-1的存在。鼻分泌物中的EHV-1仅在疫苗施用后1-2天在接种的马中检测到。环境海绵在接种疫苗的马中测试了EHV-1qPCR阳性2-5天(中位数3.5天),在单个对照马中测试了1天。通过qPCR在四个接种疫苗的马中的三个和三个对照中的两个的摊位条中检测到EHV-1仅一天。EHV-1qPCR阳性空气样品仅在一天的四匹接种马中的三匹中检测到。对于接种疫苗的马,总共有25%的鼻拭子,35%的环境失速海绵,在10个研究日期间,7.5%的条带和7.5%的空气样品的qPCR测试为EHV-1阳性。当监测亚临床EHV-1脱落者时,与鼻拭子相比,环境海绵的收集和测试能够以更高的频率检测环境中的EHV-1,固定带和空气样品。