Anthrax can be rapidly fatal to large numbers of livestock, particularly cattle. The bacteria may form spores that survive in the environment for more than 50 years. Anthrax is a zoonotic disease which means it can affect humans.
Also Anthrax is caused by a spore-forming bacterium. It mainly affects animals. Humans can become infected through contact with an infected animal or by inhaling spores.
Symptoms depend on the route of infection. They can range from a skin ulcer with a dark scab to difficulty breathing.
Antibiotic treatment cures most infections. Inhaled anthrax is harder to treat and can be fatal.
Distribution in Queensland
Anthrax occurs in Australia, most commonly in New South Wales in what is known as the ‘anthrax belt’ (from the centre of New South Wales into Victoria).
Incidents have occurred in Queensland on the Marlborough peninsula, Dirranbandi and near Wandoan.
Anthrax occurs throughout the world. Incidents can vary from occasional cases to widespread outbreaks, depending on soil, climate and degree of contamination.
Affected animalscattle; sheep; horses; goats; pigs; dogs; humans
The signs of anthrax are: sudden death in grazing animals,
weakness, staggering ,and laboured breathing
blood-stained discharges after death, usually seen at all external orifices, and rapidly decaying carcass.
Various symptoms may occur in people due to the varied nature of the disease.
Depending on the severity of the outbreak, impacts to businesses include:
increased labour due to intense animal observation
treatment and vaccination costs
decontamination and disposal costs of carcasses
consumer rejection of animal product
human health risks.
How it is spread
When exposed to air, spores form rapidly and are resistant to most external influences. They rarely persist beyond 4 years where soil moisture and microbial activity are high, but can remain viable in dry soil for much longer (upwards of 50 years).
The organism can be spread by pigs, dogs, wild birds, in flowing water, and through contamination by infected animals.
Effluent from tanneries, run-off from infected soil, and carcasses can contaminate water.
Animals become infected with anthrax from eating contaminated feedstuffs or grazing on contaminated land. Infected animals often die suddenly, with only a brief illness preceding death.
The incubation period (time from exposure to bacteria until clinical signs) is 2-14 days.
Pigs may become infected after eating contaminated blood and meat from carcasses. Cattle have been infected after chewing on old bones containing spores. Large outbreaks have resulted from contaminated feed additives such as bone flour and peanut meal. Inhalation is of minor importance in animals, but contaminated dust can be a source. Wound contamination occasionally occurs.
People are most likely to become infected when handling infected animals or breathing in anthrax spores from infected animal products (e.g. hides and wool). There are 3 forms of anthrax disease in people:
Read about Anthrax infections in people on the Queensland Health website.
Outbreaks from contaminated soil typically occur after a major climate change (i.e. rain following drought), and in warm weather when the temperature is over 15°C. Earthworks may increase risk.
In an uncontrolled outbreak, an initial case may be followed by secondary cases becoming infected from contamination by the initial case.
Monitoring and action
Call Biosecurity Queensland immediately if you suspect anthrax.
Do not open the carcass. This prevents people, other animals and the land from becoming contaminated.
If you suspect that a person has been exposed to anthrax, seek medical advice and contact a Queensland public health unit.
Control of anthrax in domestic livestock
is important for preventing its spread to people, animals and land. Control measures are to restrict movements of animals and animal products, and to vaccinate all animals at risk of exposure to infection. The disease will be controlled under the direction of Biosecurity Queensland consistent with national guidelines. Carcasses will be disposed of by deep burial or burning to minimise long-term soil contamination.
In rare cases, valuable individual animals can be treated with large doses of antibiotic. Treatment must be started quickly. It is more effective in pigs, dogs, and humans than in ruminants. Treatment with antibiotics will render vaccination ineffective, as the vaccine is live and will be killed by antibiotics. Early treatment with antibiotics for people infected with anthrax can prevent severe disease.
Rendering plants and factories processing wool and hides must adhere to workplace health and safety regulations.
If anthrax is confirmed or suspected, movements of animals and animal products from the property will be restricted. All cattle retained on the infected property, and possibly those on neighbouring properties, will be vaccinated to prevent further cases occurring.
Livestock should be excluded from areas that have previously been contaminated by anthrax.
Livestock may be protected from the impacts of anthrax by vaccination. Supply and use of anthrax vaccine requires authorisation by the Chief Veterinary Officer. Refer to your veterinarian for further information on vaccination.