Gordon Stuart J G, Bolwell Charlotte, Rogers Chris W, Musuka Godfrey, Kelly Patrick, Guthrie Alan, Mellor Philip S, Hamblin Christopher
Institute of Veterinary, Animal and Biomedical Sciences, Massey University.
Onderstepoort J Vet Res. 2017 May 10;84(1):e1-e5. doi: 10.4102/ojvr.v84i1.1445.
Sentinel herds and samples submitted by private equine practitioners were used to determine the sero-prevalence and sero-incidence of African horse sickness virus (AHSV) and equine encephalosis virus (EEV) in horse and donkey populations in the Highveld region of Zimbabwe. The sero-prevalence and sero-incidence of antibodies against these viruses were determined using the competitive enzyme-linked immunosorbent assay (ELISA) for the detection of serum antibodies. In donkeys, the median sero-prevalence of AHSV antibodies, across the three rainy seasons under study, was 75% (inter quartile range [IQR] 67-83), with a seasonal median sero-incidence of 45% (IQR 40-63). In horses, the median sero-prevalence of EEV antibodies was 63% (IQR 21-73), with a median seasonal sero-incidence of 10.5% (IQR 10-14), while in donkeys the median sero-prevalence of EEV antibodies was 80% (IQR 67-90), with a median seasonal sero-incidence of 50% (IQR 40-60). This study highlighted the significant levels of exposure of donkeys to AHSV and horses and donkeys to EEV in Zimbabwe despite equine encephalosis remaining unreported by Zimbabwean veterinarians to date. Most seroconversions in sentinel herd animals to AHSV and EEV occurred towards the end of the rainy season in March, April and May corresponding to the time of the year when the Culicoides vectors are in high abundance. In order to determine the clinical significance of these infections, blood and spleen samples, submitted by private equine veterinary practitioners over a 5-year period, from horses showing characteristic clinical signs of African horse sickness were tested for the presence of viral antigen using the antigen capture ELISA. The median sero-prevalence of AHSV antigen in horses recorded from these samples was 38% (IQR 33-88). The predominant AHSV antigen from these samples was serotype 7 (33%) followed by serotype 2 (26%) and serotypes 4 and 8 (16% each). African horse sickness virus serotypes 3 and 9, identified in this study, had not been previously reported in Zimbabwe.
利用哨兵畜群以及私人马医提交的样本，来确定津巴布韦高草原地区马和驴群体中非洲马瘟病毒（AHSV）和马脑脊髓炎病毒（EEV）的血清流行率和血清发病率。采用竞争性酶联免疫吸附测定（ELISA）检测血清抗体，以确定针对这些病毒的抗体的血清流行率和血清发病率。在驴中，在所研究的三个雨季期间，AHSV抗体的血清流行率中位数为75%（四分位间距[IQR]为67 - 83），季节性血清发病率中位数为45%（IQR为40 - 63）。在马中，EEV抗体的血清流行率中位数为63%（IQR为21 - 73），季节性血清发病率中位数为10.5%（IQR为10 - 14），而在驴中，EEV抗体的血清流行率中位数为80%（IQR为67 - 90），季节性血清发病率中位数为50%（IQR为40 - 60）。这项研究突出表明，尽管津巴布韦兽医迄今尚未报告马脑脊髓炎，但在津巴布韦，驴对AHSV以及马和驴对EEV的暴露水平很高。哨兵畜群动物中大多数针对AHSV和EEV的血清转化发生在3月、4月和5月的雨季末期，这与库蠓媒介数量众多的一年中的时间相对应。为了确定这些感染的临床意义，对私人马兽医在5年期间提交的、表现出非洲马瘟特征性临床症状的马的血液和脾脏样本，使用抗原捕获ELISA检测病毒抗原的存在情况。从这些样本中记录的马中AHSV抗原的血清流行率中位数为38%（IQR为33 - 88）。这些样本中主要的AHSV抗原是血清型7（33%），其次是血清型2（26%）以及血清型4和8（各16%）。在本研究中鉴定出的非洲马瘟病毒血清型3和9，此前在津巴布韦尚未有过报告。
