Gildea Sarah, Garvey Marie, Lyons Pamela, Lyons Rachel, Gahan Jacinta, Walsh Cathal, Cullinane Ann
Virology Unit, The Irish Equine Centre, Johnstown, Naas, Co. Kildare W91 RH93, Ireland.
Department of Mathematics and Statistics, University of Limerick, Castletroy, Limerick V94 T9PX, Ireland.
Pathogens. 2018 Apr 17;7(2):43. doi: 10.3390/pathogens7020043.
Equine influenza (EI) outbreaks occurred on 19 premises in Ireland during 2014. Disease affected thoroughbred (TB) and non-TB horses/ponies on a variety of premises including four racing yards. Initial clinical signs presented on 16 premises within a two-month period. Extensive field investigations were undertaken, and the diagnostic effectiveness of a TaqMan RT-PCR assay was demonstrated in regularly-vaccinated and sub-clinically-affected horses. Epidemiological data and repeat clinical samples were collected from 305 horses, of which 40% were reported as clinically affected, 39% were identified as confirmed cases and 11% were sub-clinically affected. Multivariable analysis demonstrated a significant association between clinical signs and age, vaccination status and number of vaccine doses received. Vaccine breakdown was identified in 31% of horses with up to date vaccination records. This included 27 horses in four different racing yards. Genetic and antigenic analysis identified causal viruses as belonging to Clade 2 of the Florida sublineage (FCL2). At the time of this study, no commercially available EI vaccine in Ireland had been updated in line with World Organisation for Animal Health (OIE) recommendations to include a FCL2 virus. The findings of this study highlight the potential ease with which EI can spread among partially immune equine populations.
2014年，爱尔兰有19处场所发生了马流感（EI）疫情。疾病影响了包括四个赛马场在内的各类场所中的纯种马（TB）和非纯种马/小马。在两个月内，16处场所出现了最初的临床症状。开展了广泛的现场调查，并证明了TaqMan RT-PCR检测方法在定期接种疫苗和亚临床感染马匹中的诊断有效性。从305匹马中收集了流行病学数据和重复的临床样本，其中40%报告有临床症状，39%被确定为确诊病例，11%为亚临床感染。多变量分析表明临床症状与年龄、疫苗接种状况和接种疫苗剂量数量之间存在显著关联。在疫苗接种记录最新的马匹中，31%出现了疫苗失效情况。这包括四个不同赛马场的27匹马。基因和抗原分析确定致病病毒属于佛罗里达亚系（FCL2）的2分支。在本研究开展之时，爱尔兰尚无任何市售EI疫苗按照世界动物卫生组织（OIE）的建议进行更新，以纳入FCL2病毒。本研究结果凸显了EI在部分免疫的马群中传播的潜在易发性。
