A virus may contribute to certain psychiatric disorders

A virus that causes a fatal brain disease in horses and sheep may be linked to certain mental disorders in man, medical experts heard today (Wednesday 09 January 2002) during a joint meeting of the European Societies of Clinical and Veterinary Virology and the Society for General Microbiology at the Royal College of Physicians, London.

“Recent investigations have again stimulated highly controversial discussions as to whether Borna disease virus can infect humans and lead to psychiatric disorders,” says Professor Norbert Nowotny of the University of Veterinary Sciences, Vienna.

Borna disease virus (BDV) is endemic in animals in certain areas of central Europe, though epidemics are rare and usually only sporadic cases of Borna disease are recorded. Horses and sheep are the main host species for this virus, although natural cases of infection have also occurred in cattle, rabbits and dogs. A wide variety of other animals including chickens and certain apes can be infected experimentally.

Professor Nowotny reveals, “Whilst BDV infection in animals leads to a severe and often lethal meningoencephalitis, such inflammation has never been seen in man. In humans, only subtle changes are suspected, which may interfere with neurotransmitter activities leading to psychiatric disorders. For example, we have detected BDV in a patient suffering from chronic fatigue syndrome.”

Professor Nowotny explains, “The link between BDV and psychiatric disorders such as some subgroups of schizophrenia and depression may be very difficult to prove for certain. However, by learning more about how the virus is transmitted we can take actions to prevent it from causing disease in humans and in animals.”