Investigation procedures for Hendra Virus
Hendra Virus (HeV) can cause a range of clinical signs in horses. If these signs occur alongside a suggestive history, notify Agriculture Victoria immediately and implement safety measures to prevent exposure to the suspect animal.
If you suspect a case of Hendra virus, contact your nearest Agriculture Victoria District Veterinary Officer or Animal Health Officer, or call the Emergency Animal Disease Hotline on 1800 675 888.
There are two case definitions for horses in Victoria where HeV infection is suspected. They are termed 'suspect cases' and 'surveillance cases'.
Suspect case
A horse is suspected to be infected with HeV if:
- there is known or suspected contact with Pteropid bats (e.g., near bat colonies, feeding or roosting areas, or bats observed locally), and
- the veterinarian considers HeV possible based on clinical signs and history (e.g., recent travel to Hendra-affected regions, unexplained horse deaths, unexplained sudden illness with rapid deterioration), and
- the horse does not have a current HeV vaccination record.
Other horses in close contact (within 5 metres) of an infected animal or those exposed to contaminated environments (e.g., death site, equipment, clothing, footwear) are also suspect cases.
Suspect cases are considered high risk and require urgent assessment and immediate isolation.
Surveillance case
A horse may be considered as a Surveillance case only if all of the following conditions are met:
- does not meet the ‘suspect’ case definition
- it shows clinical signs suggestive of Hendra
- Hendra virus is one of several differential diagnoses being considered
- the veterinarian does not believe HeV is the likely cause of the clinical signs.
Assistance from Agriculture Victoria
HeV is a notifiable disease throughout Australia. Any suspicion of HeV disease in Victoria must be reported immediately via:
- your local District Veterinary Office
- the Emergency Animal Disease Hotline on 1800 675 888.
The investigation of 'suspect' cases of Hendra can be subsidised through Significant Disease Investigation (SDI) Program funding. Surveillance cases are not eligible, but Agriculture Victoria will fund the laboratory testing for Hendra virus.
Hendra virus testing can detect both known Hendra genotypes.
Agriculture Victoria field staff will assist private veterinarians in managing HeV investigations.
Preventing exposure of people to Hendra virus
Exclude anyone not directly involved in managing infected (or ‘suspect’) horses. Horses may shed the virus for a short period before clinical signs appear.
If contact is unavoidable, wear appropriate personal protective equipment (PPE):
- impervious boots (e.g., gumboots)
- overalls
- gloves
- safety eyewear
- P2 respirator mask.
See Guidelines for veterinarians handling potential Hendra virus infection in horses, prepared by DAFF Queensland, for details.
Where possible, clean and disinfect all areas and equipment that may have been exposed to HeV. Do not perform necropsies until HeV is excluded. PPE is mandatory for everyone involved in sampling live or dead horses.
Sampling for Hendra virus exclusion
The recommended samples when testing for HeV:
- nasal swabs in viral transport media (oral and rectal swabs may also be used)
- 10 mL blood in EDTA tubes
- 10 mL blood in plain (clot) tubes
- urine-soaked swab collected immediately after urination.
Swabs from live horses should only be taken if exposure risk can be managed.
- nasal swabs in viral transport media. Oral and rectal swabs can also be used
- 10mL of blood collected in EDTA blood tubes
- 10mL of blood collected in plain (clot) blood tubes.
Swabs should only be taken from a live horse if the risk of personal exposure can be managed during sample collection.
A urine-soaked swab taken from the ground immediately after urination may also be used for testing.
More information
Further information is available on Hendra virus disease.