College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA.
Vet J. 2012 Mar;191(3):312-6. doi: 10.1016/j.tvjl.2011.11.010. Epub 2011 Dec 16.
H3N8 canine influenza virus (H3N8 CIV) was first reported as a novel canine respiratory pathogen in racing greyhounds and shelter dogs in the U.S.A. in 2004. Phylogenetic analyses determined that this host-adapted pathogen originated from interspecies transmission of an equine influenza virus (EIV), but it is unknown when the transmission occurred prior to discovery in 2004. The objective of this study was to determine if racing greyhound and shelter dog sera collected from 1984 to 2004 had serological evidence of exposure to H3N8 CIV or EIV. Archived sera from 702 racing greyhounds and 1568 shelter dogs were tested for H3 antibodies to the original 2004 CIV isolate, as well as EIV isolates from 1991 to 1999. None of the racing greyhounds from 1984 and 1985 had detectable H3 antibodies. One of the shelter dogs, which entered a north Florida shelter in 2004, was seropositive. For racing greyhounds sampled from 1999 to 2004, 133/520 (26%) dogs had antibodies to both CIV and EIV H3 proteins. The annual seroprevalence was 27% in 1999, 28% in 2000, 10% in 2001, 1% in 2002, 41% in 2003, and 28% in 2004. The odds of H3 seropositivity were greater among dogs that raced > or =6 months, raced on > or =2 tracks, and raced in 1998, 2002, and 2003. Many of the seropositive dogs raced at tracks that were involved in 'kennel cough' epidemics in 1998-1999 and 2002-2003. Based on serological evidence, a H3N8 canine influenza-like virus was circulating in racing greyhounds in the U.S.A. as early as 1999.
H3N8 犬流感病毒（H3N8 CIV）于 2004 年首次在美国被报道为一种新型犬呼吸道病原体，存在于赛犬和收容所犬中。系统进化分析表明，这种宿主适应性病原体源自马流感病毒（EIV）的种间传播，但在 2004 年发现之前，何时发生传播尚不清楚。本研究的目的是确定 1984 年至 2004 年收集的赛犬和收容所犬血清是否有 H3N8 CIV 或 EIV 暴露的血清学证据。对 702 只赛犬和 1568 只收容所犬的存档血清进行了针对原始 2004 年 CIV 分离株的 H3 抗体检测，以及针对 1991 年至 1999 年的 EIV 分离株的检测。1984 年和 1985 年的赛犬均未检测到 H3 抗体。2004 年进入佛罗里达州北部收容所的一只收容所犬呈血清阳性。1999 年至 2004 年采样的赛犬中，有 133/520（26%）只犬的 CIV 和 EIV H3 蛋白均有抗体。1999 年的年血清阳性率为 27%，2000 年为 28%，2001 年为 10%，2002 年为 1%，2003 年为 41%，2004 年为 28%。在那些赛犬中，赛犬比赛时间 > 6 个月、比赛 > 2 个赛道、1998 年、2002 年和 2003 年比赛的犬，其 H3 抗体阳性的可能性更大。许多血清阳性的犬在 1998-1999 年和 2002-2003 年“犬传染性气管支气管炎”流行的赛道上比赛过。基于血清学证据，早在 1999 年，H3N8 犬流感样病毒就在美国的赛犬中流行。
