PDF(Pubmed)
Abstract：
BACKGROUND: Rift Valley fever virus (RVFV) is a zoonotic mosquito-borne virus with serious implications for livestock health, human health, and the economy in Africa, and is suspected to be endemic in north-eastern KwaZulu-Natal (KZN), South Africa. The vectors of RVFV in this area are poorly known, although several species, such as Aedes (Neomelaniconion) mcintoshi, Aedes (Neomelaniconion) circumluteolus, Aedes (Aedimorphus) durbanensis, and Culex (Lasioconops) poicilipes may be involved. The aim of the study was to determine the vertebrate blood meal sources of potential RVFV mosquito vectors in north-eastern KZN and to characterize the host-biting network.
METHODS: Blood-fed mosquitoes were collected monthly from November 2019 to February 2023 using a backpack aspirator, CO2-baited Centers for Disease Control and Prevention (CDC) miniature light traps and tent traps, in the vicinity of water bodies and livestock farming households. The mosquitoes were morphologically identified. DNA was extracted from individual mosquitoes and used as templates to amplify the vertebrate cytochrome c oxidase I (COI) and cytochrome b (cytb) genes using conventional polymerase chain reaction (PCR). Amplicons were sequenced and queried in GenBank and the Barcode of Life Data systems to identify the vertebrate blood meal sources and confirm mosquito identifications. All mosquitoes were screened for RVFV using real time reverse transcription (RT)-PCR.
RESULTS: We identified the mammalian (88.8%) and avian (11.3%) blood meal sources from 409 blood-fed mosquitoes. Aedes circumluteolus (n = 128) made up the largest proportion of collected mosquitoes. Cattle (n = 195) and nyala (n = 61) were the most frequent domestic and wild hosts, respectively. Bipartite network analysis showed that the rural network consisted of more host-biting interactions than the reserve network. All mosquitoes tested negative for RVFV.
CONCLUSIONS: Several mosquito species, including Ae. circumluteolus, and vertebrate host species, including cattle and nyala, could play a central role in RVFV transmission. Future research in this region should focus on these species to better understand RVFV amplification.
METHODS: Blood-fed mosquitoes were collected monthly from November 2019 to February 2023 using a backpack aspirator, CO2-baited Centers for Disease Control and Prevention (CDC) miniature light traps and tent traps, in the vicinity of water bodies and livestock farming households. The mosquitoes were morphologically identified. DNA was extracted from individual mosquitoes and used as templates to amplify the vertebrate cytochrome c oxidase I (COI) and cytochrome b (cytb) genes using conventional polymerase chain reaction (PCR). Amplicons were sequenced and queried in GenBank and the Barcode of Life Data systems to identify the vertebrate blood meal sources and confirm mosquito identifications. All mosquitoes were screened for RVFV using real time reverse transcription (RT)-PCR.
RESULTS: We identified the mammalian (88.8%) and avian (11.3%) blood meal sources from 409 blood-fed mosquitoes. Aedes circumluteolus (n = 128) made up the largest proportion of collected mosquitoes. Cattle (n = 195) and nyala (n = 61) were the most frequent domestic and wild hosts, respectively. Bipartite network analysis showed that the rural network consisted of more host-biting interactions than the reserve network. All mosquitoes tested negative for RVFV.
CONCLUSIONS: Several mosquito species, including Ae. circumluteolus, and vertebrate host species, including cattle and nyala, could play a central role in RVFV transmission. Future research in this region should focus on these species to better understand RVFV amplification.
摘要：
背景：裂谷热病毒（RVFV）是一种人畜共患的蚊媒病毒，对牲畜健康有严重影响，人类健康,以及非洲的经济，怀疑是夸祖鲁-纳塔尔省东北部（KZN）的地方病，南非。该地区的RVFV载体鲜为人知，虽然有几个物种，例如伊蚊（Neomelaniconion）mcintoshi，环叶伊蚊（Neomelaniconion），伊蚊(Aedimorphus)durbanensis,和库蚊（Lasioconops）poicilipes可能涉及。该研究的目的是确定KZN东北部潜在RVFV蚊子载体的脊椎动物血粉来源，并表征宿主叮咬网络。
方法：从2019年11月到2023年2月，每月使用背包吸引器收集血液喂养的蚊子，二氧化碳诱饵的疾病控制和预防中心（CDC）微型光陷阱和帐篷陷阱，在水体和牲畜养殖户附近。对蚊子进行形态学鉴定。从单个蚊子中提取DNA，并用作模板，以使用常规聚合酶链反应（PCR）扩增脊椎动物细胞色素c氧化酶I（COI）和细胞色素b（cytb）基因。在GenBank和BarcodeofLifeData系统中对扩增子进行测序和查询，以识别脊椎动物血粉来源并确认蚊子识别。使用实时逆转录(RT)-PCR筛选所有蚊子的RVFV。
结果：我们从409只吸血的蚊子中确定了哺乳动物（88.8%）和鸟类（11.3%）的血粉来源。盘绕伊蚊（n=128）占收集蚊子的最大比例。牛（n=195）和nyala（n=61）是最常见的家养和野生寄主，分别。二分网络分析表明，农村网络比保留网络包含更多的咬宿主互动。所有蚊子的RVFV测试为阴性。
结论：几种蚊子，包括Ae.环流,和脊椎动物寄主物种，包括牛和Nyala,可以在RVFV传输中发挥核心作用。该地区的未来研究应集中在这些物种上，以更好地了解RVFV扩增。
方法：从2019年11月到2023年2月，每月使用背包吸引器收集血液喂养的蚊子，二氧化碳诱饵的疾病控制和预防中心（CDC）微型光陷阱和帐篷陷阱，在水体和牲畜养殖户附近。对蚊子进行形态学鉴定。从单个蚊子中提取DNA，并用作模板，以使用常规聚合酶链反应（PCR）扩增脊椎动物细胞色素c氧化酶I（COI）和细胞色素b（cytb）基因。在GenBank和BarcodeofLifeData系统中对扩增子进行测序和查询，以识别脊椎动物血粉来源并确认蚊子识别。使用实时逆转录(RT)-PCR筛选所有蚊子的RVFV。
结果：我们从409只吸血的蚊子中确定了哺乳动物（88.8%）和鸟类（11.3%）的血粉来源。盘绕伊蚊（n=128）占收集蚊子的最大比例。牛（n=195）和nyala（n=61）是最常见的家养和野生寄主，分别。二分网络分析表明，农村网络比保留网络包含更多的咬宿主互动。所有蚊子的RVFV测试为阴性。
结论：几种蚊子，包括Ae.环流,和脊椎动物寄主物种，包括牛和Nyala,可以在RVFV传输中发挥核心作用。该地区的未来研究应集中在这些物种上，以更好地了解RVFV扩增。
