Rates of bluetongue virus transmission between Culicoides sonorensis and sheep
Rates of bluetongue virus transmission between Culicoides sonorensis and sheep
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DOI：
10.1111/j.1365-2915.2008.00732.x
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发表时间：
2008-09-01
影响因子：
1.9
通讯作者：
Mellor, P. S.
中科院分区：
文献类型：
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作者：
Baylis, M.;O'Connell, L.;Mellor, P. S.
进行了两个实验，以估计蓝舌病病毒（BTV）血清型I之间的传播率的叮咬媒介，库蠓sonorensis（Wirth & Jones）（蠓科），和自然宿主，羊。在一项测量从媒介到宿主的传播率（V -> H）的实验中，将六批1、5和20只胸腔内感染的蠓饲喂总共18只蓝舌病（BT）未感染的绵羊。然后监测绵羊21天的BT、病毒血症和抗体应答的临床体征。所有被5只或20只吸浆虫喂养的绵羊和仅被1只吸浆虫喂养的6只绵羊中的5只表现出BT的迹象，是病毒血症并产生抗体。第六只羊被一只受感染的蠓喂养，没有表现出BT的迹象，也没有检测到病毒血症;然而，它确实产生了弱的抗体反应。因此，被一只受感染的吸浆虫叮咬一口，就能将BTV以80-100%的效率传播给未感染的绵羊。绵羊被大量感染的蠓喂养后，达到最大病毒血症的时间更短，抗体反应也更强。绵羊暴露于喂食蠓的BTV量越大，病毒血症水平越高，抗体反应越强。在第二个实验中，测量了从宿主到载体的传播率（H -> V），批次多达500个未感染的雌性C。在感染过程中，sonorensis每1-2天饲喂两只实验感染的绵羊。在3929只饱胀的蠓中，只有23只（0.6%）感染了BTV。绵羊病毒血症延长至接种后19天。然而，从感染后14天起未检测到受感染的蠓。
Two experiments were undertaken to estimate the transmission rates of bluetongue virus (BTV) serotype I between a biting midge vector, Culicoides sonorensis (Wirth & Jones) (Ceratopogonidae), and a natural host, sheep. In an experiment to measure the transmission rate from vector to host (V -> H), six batches of one, five and 20 intrathoracically infected midges were fed on a total of 18 bluetongue (BT)-naive sheep. The sheep were then monitored for 21 days for clinical signs of BT, viraemia and antibody response. All sheep fed on by five or 20 midges and five of six sheep fed on by just one midge showed signs of BT, were viraemic and developed antibody. The sixth sheep fed on by a single infected midge did not show signs of BT or have detectable viraemia; it did, however, develop a weak antibody response. A bite from a single infected midge is therefore able to transmit BTV to naive sheep with 80-100% efficiency. Sheep fed upon by larger numbers of infected midges took less time to reach maximum viraemia and developed stronger antibody responses. Sheep exposed to greater amounts of BTV in feeding midges developed a higher level of viraemia and stronger antibody responses. In a second experiment to measure the transmission rate from host to vector (H -> V), batches of up to 500 uninfected female C. sonorensis fed every 1-2 days on two experimentally infected sheep during the course of infection. Of 3929 engorged midges that were individually titrated after surviving the extrinsic incubation period, only 23 (0.6%) were infected with BTV. Viraemia in the sheep extended for up to 19 days postinoculation. No infected midges, however, were detected from 14 days post-infection.