Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime, Japan.
Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime, Japan.
Parasit Vectors. 2020 Nov 25;13(1):594. doi: 10.1186/s13071-020-04470-y.
Vector control measures are critical for the prevention and reduction of dengue virus (DENV) transmission. Effective vector control is reliant not only on knowledge of mosquito abundance, but also on the timely and accurate detection of mosquito-borne infection. Mosquito-based virus surveillance programs typically rely on pool-based mosquito testing, although whether individual-based mosquito testing is a feasible alternative to this has not been widely studied. Applying an individual-based mosquito testing approach, we conducted a 1-month surveillance study of DENV in adult Aedes aegypti mosquitoes in homes of suspected dengue patients during the 2015 peak dengue season in Tarlac City, Philippines to more accurately assess the mosquito infection rate and identify the DENV serotypes and genotypes concurrently co-circulating in mosquitoes and patients there.
We performed a one-step multiplex real-time reverse transcription-polymerase chain reaction (RT-PCR) assay for the simultaneous detection and serotyping of DENV in patients and individual female Ae. aegypti mosquitoes. Additionally, we performed sequencing and phylogenetic analyses to further characterize the detected DENV serotypes in mosquitoes and patients at the genotype level.
We collected a total of 583 adult Ae. aegypti mosquitoes, of which we individually tested 359 female mosquitoes for the presence of DENV. Ten (2.8%) of the 359 female mosquitoes were positive for the presence of DENV. We detected DENV-1, DENV-2, and DENV-4 in the field-collected mosquitoes, which was consistent with the serotypes concurrently found in infected patients. Sequencing and phylogenetic analyses of the detected DENV serotypes based on the partial sequence of the evelope (E) gene revealed three genotypes concurrently present in the sampled mosquitoes and patients during the study period, namely DENV-1 genotype IV, DENV-2 Cosmopolitan genotype, and DENV-4 genotype II.
We demonstrated the utility of a one-step multiplex real-time RT-PCR assay for the individual-based DENV surveillance of mosquitoes. Our findings reinforce the importance of detecting and monitoring virus activity in local mosquito populations, which are critical for dengue prevention and control.
病媒控制措施对于预防和减少登革热病毒（DENV）传播至关重要。有效的病媒控制不仅依赖于蚊子数量的知识，还依赖于对蚊子传播感染的及时准确检测。基于蚊子的病毒监测计划通常依赖于基于群体的蚊子检测，尽管个体蚊子检测是否是这种方法的可行替代方法尚未得到广泛研究。应用个体蚊子检测方法，我们在菲律宾塔拉克市 2015 年登革热高峰期对疑似登革热患者家中的成年埃及伊蚊进行了为期 1 个月的 DENV 监测研究，以更准确地评估蚊子感染率并确定蚊子和患者中同时传播的 DENV 血清型和基因型。
我们对患者和个体雌性埃及伊蚊蚊子进行了一步法多重实时逆转录聚合酶链反应（RT-PCR）检测，用于 DENV 的同时检测和血清分型。此外，我们还进行了测序和系统发育分析，以进一步在蚊子和患者中确定检测到的 DENV 血清型的基因型特征。
我们共收集了 583 只成年埃及伊蚊蚊子，其中我们对 359 只雌性蚊子进行了个体检测，以确定是否存在 DENV。在 359 只雌性蚊子中，有 10 只（2.8%）呈 DENV 阳性。我们在现场采集的蚊子中检测到 DENV-1、DENV-2 和 DENV-4，与同时感染患者中发现的血清型一致。基于包膜（E）基因部分序列的检测到的 DENV 血清型的测序和系统发育分析显示，在研究期间，在采样的蚊子和患者中同时存在三种基因型，即 DENV-1 基因型 IV、DENV-2 世界性基因型和 DENV-4 基因型 II。
我们证明了一步法多重实时 RT-PCR 检测在个体蚊子 DENV 监测中的实用性。我们的研究结果强调了在当地蚊子种群中检测和监测病毒活动的重要性，这对于登革热的预防和控制至关重要。
