Molecular Biology Laboratory (MBL), Department of Clinical Medicine, Faculty of Veterinary Medicine, University of Khartoum, P,O, Box 32, Khartoum North, Sudan.
Ir Vet J. 2014 Feb 7;67(1):4. doi: 10.1186/2046-0481-67-4.
Bluetongue virus (BTV) is an insect-transmitted virus, which causes bluetongue disease (BT) in sheep and a fatal hemorrhagic infection in North American white-tailed deer. However, in cattle the disease is typically asymptomatic and no overt clinical signs of disease appear to be associated with BTV infection. Serological evidence and isolation of different BTV serotypes have been reported in Sudan, however, no information is currently available in regard to previous exposure of Sudanese livestock to BTV infection in East Darfur State, Sudan.
To determine the prevalence of BTV antibodies and to identify the potential risk factors associated with BTV infection among cattle in East Darfur State, Sudan.
A total of 224 blood samples were collected randomly from five localities in East Darfur State, Sudan. The serum samples were screened for detection of BTV-specific immunoglobulin G (IgG) antibodies using a competitive enzyme-linked immunosorbent assay (c-ELISA).
Serological evidence of BTV infection was observed in 150 out of 224 animals accounting for a 67% prevalence rate among cattle in East Darfur State. Older cattle (>2 years of age) were six times more likely to be infected with BTV (OR = 6.62, CI = 2.87-15.26, p-value = 0.01). Regarding animal source (contact with other herds) as a risk factor, it was shown that cattle purchased from market or introduced from other herds were 3 times at higher risk of being infected with BTV (OR = 3.87, CI = 1.07-13.87, p value = 0.03). Exposure of cattle to the insect vector increased the risk of contracting BTV infection by six times compared to non-exposed cattle (OR = 6.44, CI = 1.53-27.08, p value = 0.01).
The present study indicated that age, animal source and the intensity of the insect vector are influential risk factors for BTV infection in cattle in the Darfur region. Surveillance for BTV infection should be extended to include other susceptible ruminants and to study the distribution of the insect vectors to better predict and respond to a possible BTV outbreak in the State of East Darfur, Sudan.
蓝舌病病毒（BTV）是一种通过昆虫传播的病毒，会导致绵羊发生蓝舌病（BT），并使北美的白尾鹿发生致命性出血性感染。然而，在牛中，这种疾病通常是无症状的，而且似乎与 BTV 感染相关的没有明显的临床症状。已在苏丹报告了血清学证据和不同 BTV 血清型的分离，但目前尚不清楚在苏丹东达尔富尔州，苏丹的牲畜以前是否曾接触过 BTV 感染。
确定 BTV 抗体的流行率，并确定与苏丹东达尔富尔州牛中 BTV 感染相关的潜在危险因素。
从苏丹东达尔富尔州的五个地点随机采集了 224 份血液样本。使用竞争性酶联免疫吸附试验（c-ELISA）检测血清样本中 BTV 特异性免疫球蛋白 G（IgG）抗体。
在 224 只动物中，有 150 只检测到 BTV 感染的血清学证据，这表明东达尔富尔州的牛的流行率为 67%。年龄较大的牛（>2 岁）感染 BTV 的可能性是 6 倍（OR=6.62，CI=2.87-15.26，p 值=0.01）。关于动物来源（与其他畜群接触）作为一个危险因素，表明从市场购买或从其他畜群引入的牛感染 BTV 的风险高 3 倍（OR=3.87，CI=1.07-13.87，p 值=0.03）。与未接触昆虫媒介的牛相比，牛接触昆虫媒介会使感染 BTV 的风险增加 6 倍（OR=6.44，CI=1.53-27.08，p 值=0.01）。
本研究表明，年龄、动物来源和昆虫媒介的强度是影响达尔富尔地区牛 BTV 感染的重要危险因素。BTV 感染的监测应扩大到包括其他易感反刍动物，并研究昆虫媒介的分布，以更好地预测和应对苏丹东达尔富尔州可能发生的 BTV 爆发。
