Transmission of classical swine fever virus by artificial insemination

Classical swine fever (CSF) virus was introduced into an artificial insemin ation centre during the CSF epizootic of 1997-1998 in the Netherlands. The risk of further spread of CSF virus via contaminated semen was recognised, but could not be assessed because scientific data on this issue were not av ailable. An animal experiment was performed to determine whether CSF virus could be transmitted via artificial insemination with contaminated semen. T hree boars were inoculated with a CSF virus field isolate and from Day 5 ti ll Day 18 thereafter, ejaculates were collected and prepared for inseminati on. Ruttish sows were inseminated with the extended semen from Day 5 till D ay 18 after inoculation of the boars. All the inoculated boars remained hea lthy throughout the experiment and developed CSF neutralising antibodies be tween 14 and 21 days after inoculation. Virus was isolated from several sem en samples collected from 5 till 11 days after inoculation. Two out of six sows inseminated with CSF contaminated semen seroconverted after inseminati on. All the other sows remained seronegative. In the foetuses of both the s eropositive sows, CSF virus was detected at approximate to 35 days post ins emination, These results demonstrate that adult boars infected with CSF vir us can excrete virus with semen and can, subsequently, transmit the virus t o sows and their foetuses via artificial insemination. (C) 1999 Elsevier Sc ience B.V. All rights reserved.