Rabies

Rabies is not known to occur in Australia.

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.

Overview

Cause

Rabies virus - belonging to the family Rhabdoviridae, genus Lyssavirus

Description

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.

Most human infections are due to rabies transmitted by dogs.

Rabies in wildlife is maintained by species such as foxes, racoons, wolves and bats.

Where the disease occurs

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 virus. A similar lyssavirus (Australian bat lyssavirus) is present in Australia.

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

The disease in animals

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. 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 behavioural changes range from a depressed/quiet form, where the animal remains quiet, and only bites when provoked, or 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 and may even attack other animals. Paralysis increases, the animal loses balance, finally cannot rise, becomes comatose and dies.
  • Sheep often have multiple cases existing at the same time in a flock, suggesting a rabid animal attack. Sheep appear restless then depressed, dying within about three days.
  • Pigs show abnormal behaviour, such as hiding and then biting if provoked, crazed appetite, killing of piglets, increasing dullness, paralysis.
  • Horses behavioural changes range from the quiet form where there is depression and difficulty swallowing (owners may think the animal has something caught in its throat) or the furious form where there is marked excitation and it is dangerous to get close to the animal.
How the disease spreads

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%) of human cases of rabies are due to bites by infected dogs.

Control of the disease in animals

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

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

Population management of stray and feral dog and cat populations reduces the pool of animals that may transmit rabies to humans.

Licensed oral vaccines are used for mass immunisation of terrestrial wildlife.

Can people get the disease?

Yes. 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 two confirmed human rabies deaths within this country (1987 and 1990). Both people were infected while overseas.

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

Treatment in people

Immediately flush wounds thoroughly with soap and water, apply a disinfectant, such as one containing iodine, and seek urgent medical advice.

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

Post-exposure medical treatment typically involves a course of rabies vaccinations. Rabies vaccines stimulate the body’s immune response, including the production of antibodies against the rabies virus. Rabies immunoglobulin, which contains readymade antibodies, may be given to provide immediate protection until the vaccine has had time to take effect.

Prevention in people

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
  • avoid contact with stray or unknown animals when in countries with endemic rabies
  • if bitten or scratched by an animal, immediately clean the wound, apply a disinfectant and, if in a country that is not free of rabies, seek urgent medical advice.

Further information

Last updated 01 July 2016