Abstract
Background: Tibet Orbivirus (TIBOV) is a recently discovered Orbivirus known to infect cattle, Asian buffalo and goats in south-western China. It was first isolated from mosquitoes and subsequently from biting midges (Culicoides spp.) in Yunnan, China, indicating that it is an arbovirus. Little is known of its potential to cause disease, but the economic importance of related viruses promoted an investigation of potential Culicoides spp. vectors of TIBOV.
Methods: Biting midges were collected approximately once per week between May and December 2020, at a cattle farm in Wulong village, Shizong County, Yunnan Province, China. Approximately 3000 specimens of nine species were subsequently used in attempts to isolate virus, and a further 2000 specimens of six species were tested for the presence of bluetongue virus (BTV) and TIBOV using a RT-qPCR test.
Results: Virus isolation attempts resulted in the isolation of three viruses. One isolate from a pool of Culicoides jacobsoni was identified as TIBOV, while the other two viruses from C. orientalis and C. tainanus remain unidentified but are not BTV or TIBOV. RT-qPCR analysis did not detect BTV in any specimens, but a single pool containing five specimens of C. jacobsoni and another containing five specimens of C. tainanus produced PCR quantification cycle (Cq) values of around 28 that may indicate infection with TIBOV.
Conclusions: The isolation of TIBOV from C. jacobsoni satisfies one criterion required to prove its status as a vector of this virus. This isolation is supported by a low Cq value produced from a different pool of this species in the RT-qPCR test. The low Cq value obtained from a pool of C. tainanus suggests that this species may also be able to satisfy this criterion. Both of these species are widespread throughout Asia, with C. jacobsoni extending into the Pacific region, which raises the possibility that TIBOV may be more widespread than is currently known. Graphical abstract: [Figure not available: see fulltext.].
| Original language | English |
|---|---|
| Article number | 432 |
| Pages (from-to) | 1-11 |
| Number of pages | 11 |
| Journal | Parasites and Vectors |
| Volume | 14 |
| Issue number | 1 |
| Early online date | 28 Aug 2021 |
| DOIs | |
| Publication status | Published - Dec 2021 |
Bibliographical note
Funding Information:We are thankful to Heng Yang (Yunnan Animal Science and Veterinary Institute, Kunming, Yunnan Province, China) for his kind gift of the primers targeting TIBOV Seg4.
Funding Information:
No evidence of infection with BTV was detected from the Culicoides in this study, which was supported by the negative result of BTV antibodies in sampled cattle. This lack of BTV infection may be caused by the relatively low livestock density in the farm studied, although Shizong County is a prevalent area of BTV.
Publisher Copyright:
© 2021, The Author(s).
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Copyright 2021 Elsevier B.V., All rights reserved.