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Published Date: 2012-12-21 02:31:55
Subject: PRO/AH> Schmallenberg virus - Europe (77): (NL, FR) virus RNA in bovine semen
Archive Number: 20121221.1462748

SCHMALLENBERG VIRUS - EUROPE (77): (NETHERLANDS, FRANCE) VIRUS RNA IN BOVINE SEMEN
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Date: Thu 20 Dec 2012
From: Wim van der Poel [edited]
<wim.vanderpoel@wur.nl>

Detection of Schmallenberg virus RNA in semen samples
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The Central Veterinary Institute (CVI) of Wageningen University and Research Centre in Lelystad, the Netherlands, and the French Agency for Food and Environmental and Occupational Health and Safety (ANSES) can confirm from their own observations the detection of Schmallenberg virus [SBV] RNA in semen samples, as reported by the Friedrich-Loeffler-Institut on 19 Dec 2012.

At CVI, 55 semen samples produced in 2012 by 8 seroconverting/viraemic bulls have been analysed using a real-time RT-PCR system developed by FLI and an RNA extraction method developed by CVI. In total, 3 samples produced by 2 different bulls tested positive.

At LNCR (National Laboratory for sanitary controls in breeding animals, France) together with ANSES, 904 semen samples produced in 2011 and 2012 by 160 seropositive bulls have been analysed using a real-time RT-PCR system developed by FLI and an RNA extraction method developed by LNCR. In total 26 samples produced by 2 different bulls were tested positive for 2 to 3 months.

Because of these findings, the institutes are currently performing in vitro and in vivo studies on SBV excretion in semen. These studies are supported by the European Union and the national governments.

In the meantime, to declare semen free of SBV, it is advised to test semen samples for the presence of SBV RNA using an approved RT-PCR and RNA extraction method, unless the semen was produced before 31 May 2011 or the bull was tested SBV antibody negative at least 28 days after production.

Prof Dr Wim H M van der Poel (Department of Virology)
Dr Ruth Bouwstra, Dr Johan Bongers (Department of Diagnostics)
Central Veterinary Institute of Wageningen University and Research Centre, Lelystad, the Netherlands.
Dr Stephan Zientara, French Agency for Food and Environmental and Occupational Health and Safety;
Dr Claire Ponsart, National Laboratory for sanitary controls in breeding animals, France.

--
Wim H M van der Poel
Department of Virology
Central Veterinarian Institute of Wageningen University and Research Centre
Lelystad
PO Box 65
The Netherlands

[The Dutch and French investigators are gratefully acknowledged for the above firsthand information, compatible with the German results as described in posting 20121220.1460864. The advised testing regimen for the certification of bovine semen for international trade will be useful during the updating process of earlier scientific advise on the issue (see http://tinyurl.com/d52da6z).

It will be interesting to compare the anticipated results of the undertaken in-vivo and in-vitro studies with the results of Australian studies involving another orthobunyavirus, Simbu-group teratogenic virus, namely the Akabane virus:

Abstract (ref 1)
"Viraemia was produced in 15 of 16 cows inoculated with Akabane virus into the uterus at oestrus and in 6 of 7 cows after intravenous inoculation. The route of inoculation did not alter the time of appearance, duration or titre of the viraemia. 4 of the 10 cows inoculated after being artificially inseminated conceived and had uneventful pregnancies. At parturition the calves were normal and there was no Akabane virus or neutralizing antibody in their pre-colostral blood.

"In a sequential study from 3 to 10 days after inoculation of Akabane virus at oestrus, the reproductive tract and other tissues of 6 cows infected by intrauterine inoculation after artificial insemination were compared with those of 7 cows receiving virus intravenously after natural service. In both groups the corpus luteum was the only tissue to show histopathological changes. The effects of lesions on the early corpus luteum of pregnancy are discussed with reference to the reported high incidence of abortions and dead foetuses in epizootics due to Akabane virus."

Reference
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Parsonson IM, Della-Porta AJ, Snowdon WA, O'Halloran ML. The consequences of infection of cattle with Akabane virus at the time of insemination. J Comp Path 1981; 9: 611-619.

It would help to note if the bovine semen tested in the German, Dutch, and French laboratories was frozen or otherwise. - Mod.AS]

See Also