Epizootiological Investigation of Getah Virus Infection among Racehorses in Japan in 2014
Epizootiological Investigation of Getah Virus Infection among Racehorses in Japan in 2014
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DOI：
10.1128/jcm.00550-15
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发表时间：
2015-07-01
影响因子：
9.4
通讯作者：
Kondo, Takashi
中科院分区：
文献类型：
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作者：
Bannai, Hiroshi;Nemoto, Manabu;Kondo, Takashi
为了阐明2014年日本美保训练中心赛马中Getah病毒感染爆发的原因，我们分离了病毒株，并对受影响的马匹和相关马匹种群进行了动物流行病学调查。从临床样本中回收了3株Getah病毒分离株，其中1株（14-I-605）用于病毒中和试验。在受累马（n = 33）中，20匹（60.6%）为2岁马。我们调查了受感染马匹和美保训练中心全体人群的盖塔病毒疫苗接种史。在2岁的人群中，接种过一次疫苗的马的患病率为14.1%。这显著高于接种两次或两次以上的马（1.3%; P < 0.01）。在从训练中心周边的茨木县和邻近的千叶县的农场进入训练中心的马中，Getah病毒的血清阳性率在2014年9月为13.0%，在2014年10月为42.9%，而在2010年和2013年同期为0%。总之，我们确定了2014年培训中心Getah病毒感染爆发的两个可能原因：（i）存在在爆发前仅接受过一剂疫苗接种的易感马，以及（ii）由于茨木县和千叶县周围农场的马中存在流行性Getah病毒感染，因此暴露于病毒的风险增加。
To clarify the factors causing an outbreak in 2014 of Getah virus infection among racehorses at the Miho training center, Japan, we isolated virus strains and performed an epizootiological investigation of affected horses and related horse populations. Three Getah virus isolates were recovered from clinical samples, and one of them (14-I-605) was used in a virus-neutralizing test. Of the affected horses (n = 33), 20 (60.6%) were 2-year-olds. We investigated the histories of Getah virus vaccination of the affected horses and the whole population at the Miho training center. Among the 2-year-old population, the prevalence of the disease in horses that had been vaccinated once was 14.1%. This was significantly higher than that in horses that had been vaccinated twice or more (1.3%; P < 0.01). Among horses that had entered the training center from farms in Ibaraki Prefecture surrounding the training center and from neighboring Chiba Prefecture, the rate of seropositivity for Getah virus was 13.0% in September 2014 and 42.9% in October 2014; that in the corresponding periods in 2010 and 2013 was 0%. In conclusion, we identified two possible causes of the outbreak of Getah virus infection in the training center in 2014: (i) the existence of susceptible horses that had received only one dose of vaccination before the outbreak and (ii) increased risk of exposure to the virus because of epizootic Getah virus infection among horses on surrounding farms in Ibaraki and Chiba prefectures.