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'.

A horse is suspected to be infected with HeV if:

• there is known or suspected contact with flying foxes (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.

A horse may be considered as a surveillance case only if all 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.

• 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 animal health and welfare staff will assist private veterinarians in managing HeV investigations.

Only people essential to providing management and care to infected or suspect horses should be permitted access to the area. Exclude anyone not directly required for their care.

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 handling or sampling live or dead horses.

The recommended samples to collect 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.

Samples should only be collected from live horses if exposure risk can be managed.