Borna disease

Borna disease is a rare and fatal neurologic disease of warm-blooded animals caused by the Borna disease virus. The disease is named after the town of Borna in Saxony, Germany, where the disease was first identified. The disease is characterized by behavioral changes, such as aggression and self-mutilation, and by the development of neurologic symptoms, such as paralysis and seizures.

Etiology

Borna disease is caused by the Borna disease virus (BDV), a nonsegmented, negative-strand RNA virus. The virus is a member of the family Bornaviridae, which is part of the order Mononegavirales. The virus is unique among animal viruses in that it replicates in the nucleus of infected cells.

Epidemiology

Borna disease has been reported in a variety of warm-blooded animals, including horses, sheep, cattle, cats, and birds. The disease is endemic in certain areas of Central Europe, but cases have been reported worldwide. The virus is thought to be transmitted through direct contact with infected animals or their secretions.

Clinical signs

The clinical signs of Borna disease vary depending on the species of animal infected. In horses and sheep, the disease is characterized by behavioral changes, such as aggression and self-mutilation, and by the development of neurologic symptoms, such as paralysis and seizures. In cats and birds, the disease may cause gastrointestinal symptoms, such as vomiting and diarrhea, in addition to neurologic symptoms.

Diagnosis

Diagnosis of Borna disease is based on the clinical signs and confirmed by laboratory tests. The virus can be detected in the blood, cerebrospinal fluid, or tissues of infected animals using polymerase chain reaction (PCR) or immunohistochemistry.

Treatment and prevention

There is no specific treatment for Borna disease. Management of the disease involves supportive care and the use of antiviral drugs, such as amantadine and ribavirin, which have been shown to inhibit the replication of the virus in vitro. Prevention of the disease involves avoiding contact with infected animals and their secretions.

In humans

There is some evidence to suggest that the Borna disease virus may be associated with certain psychiatric disorders in humans, such as schizophrenia and bipolar disorder, but this remains controversial.