Bannai Hiroshi, Nemoto Manabu, Niwa Hidekazu, Murakami Satoshi, Tsujimura Koji, Yamanaka Takashi, Kondo Takashi
Equine Research Institute, Japan Racing Association, 1400-4 Shiba, Shimotsuke, Tochigi, 329-0412, Japan.
Thermo Fisher Scientific, Life Technologies Japan Ltd, 4-2-8 Shibaura, Minato-ku, Tokyo, Japan.
BMC Vet Res. 2017 Jun 19;13(1):187. doi: 10.1186/s12917-017-1112-6.
We studied a recent epizootic of Getah virus infection among pigs in the southern part of Ibaraki Prefecture and the northern part of Chiba Prefecture, Japan, focusing on its possible association with outbreaks in racehorses in 2014 and 2015. The genomic sequence of a Getah virus strain from an infected pig was analyzed to evaluate the degree of identity with the strains from horses.
Sera were collected from pigs from September to December 2012 to 2015 in south Ibaraki (380 pigs in 29 batches), and from September to December 2010 to 2015 in north Chiba (538 pigs in 104 batches). They were examined by using a virus-neutralizing test for Getah virus. Seropositivity rates in 2012-2013 in south Ibaraki and 2010-2012 in north Chiba ranged from 0% to 1.6%. In south Ibaraki, seropositivity rates in 2014 (28.8%) and 2015 (65.0%) were significantly higher than those in the previous years (P < 0.01); 4/5 batches had positive sera in 2014 and 7/7 in 2015. In north Chiba, seropositivity rates in 2013 (14.1%), 2014 (17.8%), and 2015 (48.0%) were significantly higher than those in the previous years (P < 0.01); 6/27 batches had positive sera in 2013, 3/9 in 2014, and 5/5 in 2015. Complete genome analysis revealed that the virus isolated from an infected pig had 99.89% to 99.94% nucleotide identity to the strains isolated from horses during the outbreaks in 2014 and 2015.
Serological surveillance of Getah virus in pigs revealed that the virus was circulating in south Ibaraki and north Chiba in 2014 and 2015; this was concomitant with the outbreaks in racehorses. The Getah virus strain isolated from a pig was closely related to the ones from horses during the 2014 and 2015 outbreaks. To our knowledge, this is the first convincing case of simultaneous circulation of Getah virus both among pigs and horses in specific areas.
我们研究了日本茨城县南部和千叶县北部近期猪感染盖塔病毒的疫情，重点关注其与2014年和2015年赛马疫情的可能关联。对一株来自感染猪的盖塔病毒的基因组序列进行了分析，以评估其与来自马的毒株的同源程度。
于2012年9月至12月至2015年在茨城县南部采集了猪血清（共29批次，380头猪），并于2010年9月至12月至2015年在千叶县北部采集了猪血清（共104批次，538头猪）。使用盖塔病毒中和试验对血清进行检测。茨城县南部2012 - 2013年以及千叶县北部2010 - 2012年的血清阳性率为0%至1.6%。在茨城县南部，2014年（28.8%）和2015年（65.0%）的血清阳性率显著高于前几年（P < 0.01）；2014年5个批次中有4个批次血清呈阳性，2015年7个批次全部呈阳性。在千叶县北部，2013年（14.1%）、2014年（17.8%）和2015年（48.0%）的血清阳性率显著高于前几年（P < 0.01）；2013年27个批次中有6个批次血清呈阳性，2014年9个批次中有3个批次呈阳性，2015年5个批次全部呈阳性。全基因组分析显示，从感染猪分离出的病毒与2014年和2015年疫情期间从马分离出的毒株的核苷酸同源性为99.89%至99.94%。
对猪群进行的盖塔病毒血清学监测显示，该病毒于2014年和2015年在茨城县南部和千叶县北部传播；这与赛马疫情同时发生。从猪分离出的盖塔病毒毒株与2014年和2015年疫情期间从马分离出的毒株密切相关。据我们所知，这是盖塔病毒在特定区域猪和马中同时传播的首个确凿案例。
