Equine Influenza in Australia

In August 2007, an unprecedented outbreak of equine influenza tore through Australia. According to Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia's national science agency, equine influenza "is an acute, highly contagious, viral disease that can cause rapidly spreading outbreaks of respiratory disease in horses, donkeys, mules and other equine species." Thanks to a coordinated response, the virus was successfully contained and annihilated.

Outbreak

• A report of inquiry into the equine influenza outbreak was conducted by a former justice of the High Court of Australia, Ian Callinan. He deduced that the virus may have made its way into Australia via horses from Japan. The disease is spread from one horse to another by contaminated humans or clothing or from indirect contact with contaminated tack or equipment. Equine influenza does not pose a risk to people, nor is the disease generally fatal to horses. It can be fatal, however, to old or sick horses or young foals.

Symptoms

• Infected horses suffer from many symptoms, including a sudden spike in temperature to 102 to 106 degrees F, a dry, hacking cough and watery nasal discharge that can become thick and have a pronounced odor. Other symptoms include muscle pain and stiffness, difficulty breathing, depression and loss of appetite.

Response

• A national, coordinated response was carried out by the Australian federal government, state governments and several industry organizations. Initial quarantine of infected horses combined with effective biosecurity messages contained the disease in New South Wales and southeast Queensland.

  Scientists at CSIRO's Australian Animal Health Laboratory identified the first case of equine influenza by using serology and rapid polymerase chain reaction (PCR) tests initially created to detect the avian influenza. Equine influenza was diagnosed by sequencing part of the viral genome. After genetic sequencing of the strain, scientists were able to find the most suitable vaccine to control the spread of the virus.

  Horses near the buffer zones of the quarantined areas were vaccinated, along with high-valued, uninfected horses and horses in uninfected areas. In March 2008, it was deemed that Australia was free of the equine influenza.

Recovery

• The recovery time for most horses infected with equine influenza is about two weeks, but they require even further rest to avoid additional complications. Some horses, however, may develop secondary bacterial bronchitis or bronchopneumonia, which can lead to death if they are not treated with proper antibiotics.

Recommendations

• In the report of inquiry, Callinan made many recommendations regarding the quarantine and biosecurity arrangements for Australia's horse import systems. Horses will be tested for influenza before they are admitted to the country and while still in quarantine after arrival. Quarantine facilities will be more closely monitored, and the recommendations also call for thoroughly analyzing costs associated with the export of horses to Australia and reviewing the cost of quarantine, auditing and other risk factors. Estimates concluded that it would cost about $1.3 million to carry out these recommendations.