Pathogen test
-
The RT-cPCR test detects the genome (RNA) of Borna virus.
Sample
- 5 mL - blood - K3 EDTA tube
and/or
- 5mL - liquor (CSF) - sterile tube
Turnaround time
- 2 to 5 working days
What is Borna virus?
- Borna disease is caused by one of just a few bornaviruses that occur in a wide variety of warm-blooded animals.
- This virus attacks the nerve cells within the brain itself causing dangerous levels of inflammation.
- This virus is frequently lethal once symptoms begin presenting themselves, however, antibodies specific to the virus have frequently been found in the blood of animals who are clinically unaffected. This suggests that some horses and other animals may become infected and remain asymptomatic.
- Borna disease is a rare viral infection that causes swelling of the nerve cells in the brain, leading to unusual behaviours and seizures, and is frequently fatal.
Clinical signs
The clinical signs of Borna disease usually occur in horses two to three months after the initial exposure, although there have been reports of incubation periods exceeding six months.
- Blindness
- Chewing motions
- Colic symptoms
- Collapse
- Head-pressing
- Hypersensitivity
- Lack of coordination
- Leaning
- Loss of appetite
- Muscular tremors
- Paralysis Rapid and involuntary eye movement
- Sawhorse stance
- Severe depression
- Weakness
- Yawning
Transmission
- The virus that causes Borna disease in horses is closely related to the bornavirus that affects birds and is believed to be the cause of Proventricular Dilatation Disease (PDD) in birds.
- The transmission methods for these viruses are not well understood, but direct contact with either saliva or nasal secretions are believed to be a common vector.
- Borna disease emerges more frequently on farms with poor rodent control and hygiene, and instances seem to peak during the months between March to June.
Prevention
- Experimental vaccines for immunopathology have had mixed results. In some cases, the immunopathology of the infection caused some vaccines to exacerbate the disease, but recent evidence suggests the possibility of effective inoculation.
- Although some preliminary research indicates success with protective vaccination of mice, at this writing, no pre-exposure vaccine has been developed for use with horses.
Treatment
- The antiviral drug amantadine sulfate may be a potential treatment for Borna disease virus. It has been demonstrated in vitro to inhibit wild-type BDV replication and spread of infection.
- As with prevention of the disease, much research is needed to develop successful treatment strategies because, currently, the fatality rate ranges between 60 to 95 percent for horses, and animals that survive often remain neurologically impaired permanently.