by Dr Ron Glanville,
Chief Veterinary Officer
Department of Primary Industries and Fisheries
The graph below shows the spread of the infection based on the date of onset of clinical signs of equine flu.
The dotted line shows the total number of infected premises (IPs) reported on a "5 day rolling average".
The peak number of infected premises was around 1 October 2007. Since then there has been a consistent decline in the number of premises reporting clinical signs.
But the infection rate can still accelerate and this is no time for complacency.
Biosecurity precautions including showering, washing, disinfecting footwear and vehicles, changing into clean clothing, and not touching other horses are still vital.
While this graph shows that at the end of October there were about 1900 IPs, many of the very early IPs have now passed the 30-day period since the last horse showed signs of EI, and horses on these premises are no longer infectious.
It is still critically important that we stop the disease from spreading to new districts.
People are still the greatest risk of spreading the disease to new areas so please maintain good biosecurity and decontamination and continue observing the movement restrictions in the Red Zone.
The equine influenza horse industry liaison officers have compiled a list of common myths circulating on various websites and blogs. I have commented on these below:
1. Vaccination will guarantee my horse does not get equine influenza
FALSE - there are very few vaccines for any disease in any species of animal (including humans) that provide 100% protection from a disease. The Genetically Modified Canary Pox vaccine being used is Queensland was selected as it rapidly produces immunity and because it is possible to distinguish between infected animals and vaccinated animals.
Vaccinated horses can still be affected by equine influenza infection and still shed the virus for a short period. The signs of disease are usually milder than those in non-vaccinated horses.
2. Vaccination does not have any side effects
FALSE - in a very few cases a small swelling may be noticed at the vaccination site.
As with any vaccine, the EI vaccine can cause a severe and potentially fatal reaction called anaphylactic shock. However this is extremely rare and it is one of the reasons why the vaccine should be administered by a vet.
3. A vaccinated horse cannot infect other horses
FALSE - a vaccinated horse can still shed virus, albeit normally for shorter periods. Spread can still occur to other horses, or a person can transfer the virus to other horses on their hands, hat, boots and clothes.
4. Vaccination of horses will cure the Equine Influenza disease outbreak
FALSE - vaccination of horses is not the cure for equine influenza. The disease must be contained and will burn itself out if it is stopped from spreading. Vaccination does considerably reduce the amount of virus that horses produce. The less virus in and around the infected areas, the less chance of the disease spreading.
5. If all horses in the Red Zone were vaccinated, the disease problem would be fixed forever.
FALSE - vaccinated horses can still spread the disease. It is better to keep horses disease free and allow infected horses to recover and develop strong natural immunity.
6. Once horses are vaccinated they can move freely in the red zone
FALSE - vaccinated horses cannot move freely in the red zone. The regulations for horse movement apply to both vaccinated and unvaccinated horses. However we are working closely with industry on protocols to free up movements as the EI epidemic wanes. Vaccination status of horses is one of the considerations in developing these protocols.