Section for Virology, National Veterinary Institute, Technical University of Denmark, Lindholm, DK-4771 Kalvehave, Denmark.
Vet Microbiol. 2013 Jul 26;165(1-2):173-6. doi: 10.1016/j.vetmic.2013.01.003. Epub 2013 Jan 23.
In 2011 African swine fever virus (ASFV) genome was detected in asymptomatic pigs in field samples in Mbeya, Tanzania. The aim of this paper is to partly characterize the virus that was harbored in these pigs and furthermore to confirm, by a second sampling, the latest occurrence of ASFV in the study area. ASFV genome was detected in serum from 10 out of 127 healthy European/crossbreed pigs. ASFV DNA was polymerase chain reaction (PCR) amplified and sequenced from sera with high viral loads using primers targeting p54 or p72. Both p54 and p72 had total identity to ASFV Genotype II (Georgia 2007/1). The ASFV epidemiology in Mbeya was studied in a new collection of 804 pig sera obtained in 2012. The antibody prevalence in four age groups (3-6 months.; 7-12 months; 13-18 months or 19-36 months) was 3-5%; all antibody positive sera were analyzed by PCR with negative results. The presence of antibodies in 3-month-old pigs confirms the circulation of ASFV in Mbeya several months after our detection of ASFV in asymptomatic pigs. The initial blood samples were obtained on Whatman FTA filter papers as dried blood samples. The samples were stored under field conditions and ASFV could be sequenced in DNA eluted 10 months later, showing the use of FTA samples. Studies on the genetic breed of the pigs are needed as well as sequence studies including the variable region of ASFV to elucidate why asymptomatic pigs with high viral loads were detected.
2011 年，在坦桑尼亚姆贝亚的野外样本中，检测到了非洲猪瘟病毒（ASFV）的基因组。本研究旨在对这些猪所携带的病毒进行部分特征分析，并通过第二次采样，进一步确认 ASFV 在研究区域的最新发生情况。从 127 头健康的欧洲/杂交猪中，有 10 头血清中检测到了 ASFV。利用针对 p54 或 p72 的引物，对高病毒载量的血清进行聚合酶链反应（PCR）扩增和测序，从而检测到了 ASFV 基因组。p54 和 p72 与 ASFV 基因型 II（格鲁吉亚 2007/1 株）完全一致。在 2012 年收集的新的 804 份猪血清中，研究了姆贝亚的 ASFV 流行病学。在四个年龄组（3-6 个月；7-12 个月；13-18 个月或 19-36 个月）中，抗体阳性率为 3-5%；所有抗体阳性的血清均用 PCR 进行了分析，结果均为阴性。3 个月大的猪存在抗体，证实了 ASFV 在姆贝亚的传播，这比我们首次在无症状猪中检测到 ASFV 要早几个月。初始血液样本取自 Whatman FTA 滤纸条上的干血样。样本在野外条件下储存，10 个月后可从洗脱的 DNA 中测序，表明可以使用 FTA 样本。需要对猪的遗传品种进行研究，并进行包括 ASFV 可变区在内的序列研究，以阐明为什么会检测到具有高病毒载量的无症状猪。
