Yunnan Tropical and Subtropical Animal Virus Diseases Laboratory, Yunnan Animal Science and Veterinary Institute, Fengyu Road, Panlong District, Kunming 650224, Yunnan, China - Key Laboratory of Transboundary Animal Diseases Prevention and Control (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Fengyu Road, Panlong District, Kunming 650224, Yunnan, China.
Research Institute for the Environment and Livelihoods, Charles Darwin University, Ellengowan drive, Casuarina, NT 0810, Australia.
Parasite. 2024;31:72. doi: 10.1051/parasite/2024072. Epub 2024 Nov 19.
Culicoides spp. (Diptera: Ceratopogonidae) are small biting midges, some of which are the vectors of arboviruses affecting livestock, i.e., African horse sickness virus (AHSV), bluetongue virus (BTV), and epizootic hemorrhagic disease virus (EHDV). Yunnan Province, located in southwestern China, has a history of high prevalence of arboviruses. The diversity and abundance of Culicoides was observed between March 2022 and March 2023 on two cattle farms in Lufeng County of Yunnan Province, China and virus isolation and PCR detection were attempted from cattle blood and Culicoides spp. collected from the farms. Light trap collections contained 19 species of Culicoides belonging to 8 subgenera and one unplaced species group and were dominated by C. oxystoma (63.4%), C. imicola (16.2%), C. arakawae (13.4%), C. sp. near newsteadi (2.3%), and C. orientalis (1.7%). A total of 8,343 Culicoides were used for statistical analysis; from these collections 997 Culicoides specimens belonging to 10 species were screened for the presence of BTV, EHDV, Yunnan Orbivirus (YUOV), and Yongshan totivirus (YSToV) using reverse transcription quantitative PCR (RT-qPCR). One strain of YUOV was isolated from cattle blood and 7 isolates of YSToV were isolated from 5 different species of Culicoides. BTV and YSToV were detected from 2 and 3 pools of parous C. imicola specimens by RT-qPCR, respectively, which is the first report of a totivirus to be associated with Culicoides. Culicoides imicola is likely to be the major vector of Culicoides-borne arboviruses in Lufeng County, which is a relatively dry locality, and adult C. imicola may play a role of BTV overwintering.
类蚊蠓（双翅目：蠓科）是小型吸血蠓，其中一些是影响牲畜的虫媒病毒的载体，即非洲马瘟病毒（AHSV）、蓝舌病病毒（BTV）和流行性出血热病毒（EHDV）。云南省位于中国西南部，曾有虫媒病毒高发的历史。2022 年 3 月至 2023 年 3 月，在中国云南省禄丰县的两个牛场观察到类蚊蠓的多样性和丰度，并尝试从牛血和从农场收集的类蚊蠓中分离病毒和进行 PCR 检测。灯光诱捕收集到的类蚊蠓共有 19 种，属于 8 个亚属和一个未定位的种组，其中以 C. oxystoma（63.4%）、C. imicola（16.2%）、C. arakawae（13.4%）、C. sp. near newsteadi（2.3%）和 C. orientalis（1.7%）为主。共使用 8343 只类蚊蠓进行统计分析；从这些收集物中，筛选了 997 只属于 10 种的类蚊蠓标本，用反转录定量 PCR（RT-qPCR）检测 BTV、EHDV、云南 orbivirus（YUOV）和永善甲病毒（YSToV）的存在。从牛血中分离到一株 YUOV 病毒株，从 5 种不同种类的类蚊蠓中分离到 7 株 YSToV 病毒株。在 2 个和 3 个充满怀孕 C. imicola 标本的池中，通过 RT-qPCR 检测到 BTV 和 YSToV，这是首次报道与类蚊蠓有关的甲病毒。在禄丰县，类蚊蠓可能是携带类蚊蠓的虫媒病毒的主要媒介，禄丰县是一个相对干燥的地区，成年的 C. imicola 可能在 BTV 越冬中发挥作用。
