With Hendra Virus back in the news again with new cases in Queensland and Northern New South Wales I thought I would share a little bit of information on this very scary virus.
Hendra Virus was first discovered back in September 1994 at a horse training complex in the Brisbane suburb of Hendra, where it took the life of thirteen horses and their trainer. In 1995 a Mackay man died from Hendra Virus which was later confirmed to be contracted back in August 1994 when two horses were later confirmed to have died from the virus.
In the past years Hendra Virus has proven to be most prevalent from June to October, but it is definitely not limited to these months. It seems that higher levels of the virus are being shedded by infected flying foxes during these time. This is possibly related to the flying fox birthing season and excretion of contaminated afterbirth, as well as the flying foxes being more stressed due to fighting for food. The black and spectacled flying foxes that carry the virus are generally found in Queensland and Northern New South Wales and this is why outbreaks are being isolated to these areas.
Hendra Virus does not have any ill effect on the flying foxes that are contaminated with the disease. With no known cure for Hendra Virus the effect on horses and people is much more severe. Over 75% of horses that contracted the disease have died and out of the seven people infected with Hendra Virus four of them have lost their lives.
Hendra Virus is transmitted from Flying Foxes to Horses through fluid secretions including saliva, urine or afterbirth and faeces. Horses can then contract the disease by ingesting contaminated materials like feed, hay, grass or water. It can then be passed from horse to horse through direct contact with infectious bodily fluids or by contact with contaminated equipment. Hendra Virus can then be transmitted to people via close contact with an infected horse through their respiratory secretions (mucus), blood or other bodily fluids. There have also been cases of Hendra Virus transmitting between horses and dogs. There is no evidence that Hendra Virus can pass directly from flying foxes to humans.
Hendra Virus has shown to have a very broad range of symptoms and therefore it does need to be considered when no particular cause can be found for illness, particularly if there is rapid onset, quick deterioration, high fever, respiratory distress or neurological signs.
Signs and symptoms that have been associated with Hendra Virus include, but not limited to,
* rapid onset of illness
* high temperature
* increased heat rate
* respiratory distress or increased respiration
* nasal discharge
* neurological signs including, muscle twitching, inability to stand, wobbling, uneasy on feet, head tilting.
If you have any concerns about your horses health or they are showing these signs please contact your veterinarian immediately to discuss.
Not only are horses at risk from this virus but people handling infected horses could also become infected. If you need to come into contact with a horse that has or is suspected of having Hendra Virus you must take precautions to protect yourself. Wear personal protective clothing and equipment when dealing with sick animals. Wear overalls, rubber boots, disposable gloves, safety shields and safety glasses. Make sure that after handling a sick horse that the equipment is disposed of correctly or that a disinfectant is used to wash equipment. Make sure to wash your hands thoroughly with soap and water or a disinfectant if possible.
Humans that have contracted the virus from horses have become sick within 5-21 days after exposure to an infected horse. Their symptoms have included flu like symptoms with fever, cough, tiredness, sore throat and headache. Then progressing to encephalitis which is swelling of the brain causing headaches, high fever, drowsiness, convulsions and/or coma. If you have been in contact with a suspected Hendra Virus horse please be aware of these signs and contact a medical practitioner immediately if you have any symptoms.
There are few things you can do to possibly reduce the chances of your horse from contracting the Hendra Virus. Where possible move feed, water containers and shelters from under trees. If you can, remove horses from paddocks or fence of areas that might attract flying foxes like fruiting or flowering trees. Clean and disinfect equipment after use and avoid sharing equipment between horses and ensure strict hygiene practises when handling horses. If you do have a sick horse isolate the horse immediately and contact your veterinarian.
A vaccination for Hendra Virus is now available for horses called Equivac HeV. This vaccination can only be obtained and administered by a certified veterinarian. For a horse to be fully vaccinated it requires two vaccinations, 21 days apart, with full immunity being reached 21 days after the second dose. At the moment a booster vaccination will be required after 6 months but this may be extended to 12 months as clinical trials are still taking place. Vaccination is highly recommended especially in areas with flying fox populations. Vaccination against Hendra Virus is the most effective way to protect your horse. However, it is important to remember that vaccinations are not always 100% effective and continued vigilance in hygiene practices and looking for signs of Hendra should still be undertaken. For more information on the vaccine, Equivac HeV, please visit the Equine Veterinary Association website and read “Your Hendra Virus vaccine questions answered”.
It is possible that vaccination will become mandatory for all horses that are competing at shows or events. This year the Brisbane RNA Show has ruled that all horses entering the showgrounds must be fully vaccinated for Hendra Virus and must be able to produce the vaccination certificate. This is to try and ensure the safety of the horses and people that are at the show by reducing the risk of Hendra Virus being contracted or spread.
If you ever suspect that your horse may have Hendra Virus contact your veterinarian immediately. If you are unable to get a veterinarian to examine the horse notify a government veterinarian or contact Biosecurity in your state. It is a legal obligation that all suspected and confirmed cases of Hendra Virus are reported to Biosecurity Queensland on 13 25 23 or Emergency Animal Disease Watch Hotline on 1800 675 888.
For further information on Hendra Virus please read the Queensland Government’s, Department of Agriculture, Fisheries and Forestry, Hendra Virus Brochure.
So as we lead into the most dangerous time for Hendra Virus please make sure that if you are in contact with horses that you take extra care and precautions, keeping in mind that Hendra Virus is around and very dangerous.
Until next time,
Information sourced from;