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Hendra Virus

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Ratification Date: 19 Oct 2018

Policy

Precautions must be taken by horse owners, handlers and veterinary staff to minimise the risk of Hendra virus infection in horses and people. For veterinarians and others operating businesses involving horses, this is a legal obligation under work health and safety laws that can be enforced through prosecution.

In areas known to have had Hendra virus infection in horses, owners must be mandated to vaccinate their horses against Hendra virus. This is so that they, and others coming into contact with their horses, are not put at risk of contracting the disease.

All vaccinations of horses against Hendra virus must be recorded in the central database to ensure accurate information on vaccination status is available to veterinarians and other people in contact with sick horses.

Background

Hendra virus (HeV) is a serious, potentially fatal virus that is spread from flying foxes to horses, and from infected horses to humans. The clinical signs of Hendra virus in horses are varied and may include fever, elevated heart and respiratory rates, nasal discharge, ataxia, muscle twitching, recumbency, blindness or sudden death.1 Diagnosis of Hendra virus infection in horses is impossible without laboratory confirmation.

Vaccination of horses is the most effective way to help manage Hendra virus disease. Other preventive measures are those which aim to minimise contact between horses and flying foxes. Additional precautions to protect people include using personal protective equipment, and implementing good hygiene and infection control practices when handling horses.

The most appropriate precautions in any given circumstance will depend on a range of factors including the geographical location, vaccination status of the horse, the presence of flying foxes, previous cases in the local area, the nature of any presenting signs in the horse, and the risk of exposure to infectious bodily fluids.

A key consideration is that an infected horse can shed Hendra virus before it shows any signs of illness. This means that there is a risk of apparently healthy horses infecting other horses or people with Hendra virus up to 3-5 days before the onset of illness.2

Vaccination of horses against Hendra virus provides a work health and safety and public health benefit.3

Mandatory vaccination can be achieved through government legislation or through mandatory programs implemented by industry. Both may be necessary to achieve the level of vaccination required to protect the community.

Because of the many variables that affect the potential risk of infection for people, veterinarians undertake a risk analysis to decide how best to protect themselves and others against Hendra virus. There are also government guidelines in Queensland and New South Wales on how to manage the risk of Hendra virus in veterinary practice.2,4,5 The policy responses of veterinary practices will vary due to the range of factors that influence risk. As the examination of seemingly healthy horses still poses risk, some practices consider that the risk of examining unvaccinated horses is too high given the potentially fatal consequences of infection.

Section 19 (2) of the Queensland Workplace Health and Safety Act 2011 states that “A person conducting a business or undertaking must ensure, so far as is reasonably practicable, that the health and safety of other persons is not put at risk from work carried out as part of the conduct of the business or undertaking.” Similar legal requirements are in place in other states and territories, and can be enforced by prosecution of any workers in contact with horses that may contract Hendra virus.

The Equivac HeV vaccine is fully registered with the Australian Pesticides and Veterinary Medicines Authority.

Sick, unvaccinated horses from areas where there have been known Hendra virus infections must have Hendra virus infection ruled out by the collection of blood and nasal, oral and rectal swabs by the attending veterinarian. Until results of Hendra virus exclusion testing are received, horses may receive sub-optimal therapy, and diagnostic procedures will be limited. This is in order to comply with the requirements of workplace health and safety laws, and to minimise the risk of transmission of the disease to people. It may result in suffering that could have been avoided by prior vaccination of these animals against Hendra virus.

References

  1. https://www.daf.qld.gov.au/animal-industries/animal-health-and-diseases/...
  2. Biosecurity Queensland. Guidelines for veterinarians handling potential Hendra virus infection in horses. Brisbane, 2011. Available: https://www.daf.qld.gov.au/__data/assets/pdf_file/0005/126770/2913_-Guid...
  3. Hendra Virus Protection Advice. Hendra Virus interagency technical working group report, October 2014.
  4. NSW Department of Primary Industries, Hendra virus work health and safety responsibilities, July 2014. Available: http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0008/523592/hendra-work...
  5. Workplace Health and Safety Queensland, Hendra virus – information for veterinarians, August 2015. Available: https://www.worksafe.qld.gov.au/__data/assets/pdf_file/0010/82981/alert-...

Date of ratification by the AVA Board: 10 May 2016

Updated 19 October 2018