Environmental Health Institute, National Environment Agency, Singapore, Singapore.
PLoS Negl Trop Dis. 2013 Aug 1;7(8):e2348. doi: 10.1371/journal.pntd.0002348. Print 2013.
Zika virus (ZIKV) is a little known arbovirus until it caused a major outbreak in the Pacific Island of Yap in 2007. Although the virus has a wide geographic distribution, most of the known vectors are sylvatic Aedes mosquitoes from Africa where the virus was first isolated. Presently, Ae. aegypti is the only known vector to transmit the virus outside the African continent, though Ae. albopictus has long been a suspected vector. Currently, Ae. albopictus has been shown capable of transmitting more than 20 arboviruses and its notoriety as an important vector came to light during the recent chikungunya pandemic. The vulnerability of Singapore to emerging infectious arboviruses has stimulated our interest to determine the competence of local Ae. albopictus to transmit ZIKV.
METHODOLOGY/PRINCIPAL FINDINGS: To determine the competence of Ae. albopictus to ZIKV, we orally infected local mosquito strains to a Ugandan strain virus. Fully engorged mosquitoes were maintained in an environmental chamber set at 29°C and 80-85%RH. Twelve mosquitoes were then sampled daily from day one to seven and on day 10 and 14 post infection (pi). Zika virus titre in the midgut and salivary glands of each mosquito were determined using tissue culture infectious dose50 assay, while transmissibility of the virus was determined by detecting viral antigen in the mosquito saliva by qRT-PCR. High dissemination and transmission rate of ZIKV were observed. By day 7-pi, all mosquitoes have disseminated infection and 73% of these mosquitoes have ZIKV in their saliva. By day 10-pi, all mosquitoes were potentially infectious.
CONCLUSIONS/SIGNIFICANCE: The study highlighted the potential of Ae. albopictus to transmit ZIKV and the possibility that the virus could be established locally. Nonetheless, the threat of ZIKV can be mitigated by existing dengue and chikungunya control program being implemented in Singapore.
寨卡病毒（ZIKV）是一种鲜为人知的虫媒病毒，直到 2007 年在太平洋岛国雅浦爆发了一次重大疫情。尽管该病毒的地理分布广泛，但已知的大多数传播媒介都是来自非洲的丛林型埃及伊蚊，该病毒最初就是在那里分离出来的。目前，埃及伊蚊是唯一已知能在非洲大陆以外传播该病毒的媒介，但白纹伊蚊长期以来一直被怀疑是一种传播媒介。目前，白纹伊蚊已被证明能够传播 20 多种虫媒病毒，其作为重要传播媒介的恶名在最近的基孔肯雅热大流行中显现出来。新加坡易受新发传染病的虫媒病毒的影响，这激发了我们的兴趣，以确定当地白纹伊蚊传播寨卡病毒的能力。
方法/主要发现：为了确定白纹伊蚊对寨卡病毒的易感性，我们用乌干达分离株病毒经口感染了当地的蚊株。充分吸血的蚊子在 29°C 和 80-85%RH 的环境室中饲养。然后，从感染后第 1 天到第 7 天，以及第 10 天和第 14 天，每天从 12 只蚊子中采样。采用组织培养感染剂量 50 测定法，检测每只蚊子中中肠和唾液腺中的寨卡病毒滴度，通过 qRT-PCR 检测病毒抗原在蚊子唾液中的存在来确定病毒的传播能力。观察到寨卡病毒的高传播和高传播率。到第 7 天感染后，所有蚊子都已传播感染，其中 73%的蚊子唾液中含有寨卡病毒。到第 10 天感染后，所有蚊子都具有潜在的感染性。
结论/意义：该研究强调了白纹伊蚊传播寨卡病毒的潜力，以及该病毒可能在当地建立的可能性。尽管如此，新加坡实施的登革热和基孔肯雅热控制计划可以减轻寨卡病毒的威胁。
