Rabies

Rabies is prohibited matter.

Under Queensland legislation, if you suspect the presence of this disease in any species of animal, you must report it to Biosecurity Queensland on 13 25 23 or contact the Emergency Disease Watch Hotline on 1800 675 888.

Rabies is a viral disease that affects humans and other mammals. It affects the central nervous system and is of great public health and veterinary concern.

There are several variants of rabies virus, each adapted to a specific reservoir host. Rabies causes progressive inflammation of the brain and spinal cord (encephalitis) resulting in death.

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, there have been 2 confirmed human rabies deaths here (1987 and 1990). Both people were infected while overseas.

Scientific name

Rabies virus, belonging to the family Rhabdoviridae, genus Lyssavirus

Distribution in Queensland

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.

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

foxes; raccoons; wolves; bats; humans; cats; sheep; pigs; horses; cattle; potentially any other mammal

Hosts

Dogs are the most significant hosts for rabies. Dog-variant rabies is responsible for most human infections.

Other variants of rabies virus are also maintained in wildlife species such as foxes, raccoons, skunks, wolves and bats.

Other mammals such as cats, horses, cattle and other domestic animals may be affected by rabies, and may transmit the infection to humans, but do not have their own variants of the virus or sustain ongoing cycles of infection within their populations.

Symptoms

The clinical signs of rabies are variable, depending on the effect on the brain. Rabies often causes sudden behavioural changes, followed by progressive paralysis, coma and death. Behavioural changes include the following.

Dogs and cats

  • Symptoms range from a depressed quiet form, where the animal remains quiet and only bites when provoked

to

  • a furious form with unusual restlessness, snapping at imaginary objects 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

  • Changes range from the quiet form, where there is depression and difficulty swallowing (owners may think the animal has something caught in its throat)

to

  • the furious form, where there is marked excitation and it is dangerous to get close to the animal.

Impacts

Once symptoms develop, there is no cure and death is almost certain. However, with timely medical intervention, the disease is easily preventable. For this reason, all potential rabies exposures should be treated as a medical urgency.

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.

Control

Prevention in animals

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

Rabies vaccines that prevent the development of rabies disease are available for dogs, cats, horses, cattle, sheep and ferrets.

Licensed oral vaccines are used for mass immunisation of 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, 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.

More information