Rabies due to rabies virus

Alert

Rabies virus is prohibited matter.

Under Queensland legislation, if you believe rabies virus is present in any species of animal, you must report it to Biosecurity Queensland on 13 25 23 or contact the Emergency Animal Disease Watch Hotline on 1800 675 888.

Rabies virus invariably causes fatal disease in humans and other mammals. It affects the central nervous system and is of great public health and veterinary concern.

Scientific name

Rabies disease

Cause

Rabies virus, belonging to the family Rhabdoviridae, genus Lyssavirus

There are several variants of rabies virus, each adapted to a specific reservoir host.

Similar species

Distribution

Rabies is present in most parts of the world including Europe, Africa, the Americas, the Middle East and most of Asia.

Australia, New Zealand, the United Kingdom, Japan, Singapore, Papua New Guinea and the Pacific Islands are free of rabies. A similar lyssavirus (Australian bat lyssavirus) is present in Australia.

Since December 2008, rabies in dogs has spread to previously uninfected islands in the Indonesian archipelago, including spreading to the popular tourist destination of Bali.

Hosts

  • Dogs – host for dog-mediated rabies, are responsible for most human infections.
  • Wildlife, including foxes, raccoons, skunks, wolves and bats are the hosts of other variants of rabies virus

Life cycle

Signs of illness in animals can develop anywhere between 10 days and several months to years after infection. Once signs of illness arise, death typically occurs within 10 days.

In people, the incubation period is typically 1-3 months but may vary from less than 1 week to several years.

Affected animals

  • potentially any mammal, including humans, dogs, cats, livestock, and wildlife.

Clinical signs

The clinical signs of rabies vary but are generally consistent with the signs of encephalitis (inflammation of the brain) in that species. Rabies often causes sudden behavioural changes, followed by progressive paralysis, coma and death.

Dogs and cats

  • Clinical signs range from being depressed and quiet, where the animal only bites when provoked
  • to

  • unusual restlessness, snapping at imaginary objects, aggression and biting and eating strange objects such as sticks and stones.

Cattle

  • Become depressed
  • Stop producing milk
  • May grind their teeth
  • Salivate
  • Bellow
  • Have increased sexual activity
  • May attack other animals
  • Become increasingly paralysed, lose balance, finally cannot rise, become comatose, die.

Sheep

  • Often have multiple cases existing at the same time in a flock, suggesting a rabid animal attack
  • Appear restless then depressed, dying within about 3 days.

Pigs

  • Show abnormal behaviour, such as hiding and then biting if provoked
  • Develop a crazed appetite
  • Kill piglets
  • Are increasingly dull
  • Become paralysed.

Horses

  • Clinical signs range from depression and difficulty swallowing (owners may think the animal has something caught in its throat)
  • to

  • marked excitation and it being physically dangerous to get close to the animal.

Impacts

Once symptoms develop, there is no cure and death is almost certain.

Over 55,000 people die of rabies worldwide each year. More than 95% of human deaths occur in Asia and Africa.

Although rabies virus is exotic to Australia, people have died in Australia from rabies infections caught while overseas.

How it is spread

Rabies is transmitted through the saliva of an infected animal.

Infection usually occurs when infectious saliva comes into contact with fresh wounds (e.g. bites and scratches) and unprotected mucous membranes (e.g. eyes and mouth) of non-vaccinated animals and people. Most (95%) human cases of rabies are due to bites by infected dogs.

Human-to-human transmission of rabies can occur as a result of organ transplant from an infected person.

Risk period

All year round.

Monitoring and action

A dog that bites a person and dies within 10 days should be reported to Biosecurity Queensland and submitted for urgent testing.

Control

Prevention in animals

In countries where rabies is endemic, control relies on pre-exposure vaccination programs and the management of stray animal populations.

Because Australia is free of rabies, animal rabies vaccines have not been licenced for pre-exposure in Australia. Pets being exported to rabies-endemic countries should be vaccinated prior to departure.

Overseas, oral vaccines are used to mass vaccinate wildlife.

Prevention in humans

Rabies infection can be prevented through several simple courses of action:

  • Seek medical advice about pre-exposure vaccination before travelling to a region with endemic rabies, particularly if contact with wildlife or dogs is likely.
  • If bitten or scratched by an animal in a country that is not free of rabies, immediately clean the wound, apply a disinfectant, and seek urgent medical advice.

Treatment for humans

  • Clinical disease is almost invariably fatal.
  • If you are ill with signs consistent with rabies, seek urgent medical advice.

However, if bitten by a rabid animal, progression to clinical disease (getting sick) and death may be prevented by urgent post-exposure vaccination. All potential rabies exposures should be treated as a medical emergency.

Quarantine

Australia has strict import conditions on mammals to prevent the entry of rabies and other diseases.

Further information