Brucellosis

There are a number of diseases found in animals that can be transmitted to humans. These diseases are called zoonoses. Zoonoses are caused by particular disease causing organisms such as bacteria and viruses and by worms and parasites.

Any person involved in handling animals or animal products is potentially at risk of infection.

What is Brucellosis?

Brucellosis is an infectious disease found in animals that can be transmited to humans. It is caused by a bacteria called brucella found mainly in cattle and pigs. Therefore, it is an occupational hazard faced by individuals employed in meat industries.

Brucellosis is also known as Ungulant Fever and may be difficult to diagnose in exposed workers and may not always be reported.

Any one who has a history of contact with domestic cattle may have risked exposure the Brucellosis. Workers most at risk are those in animal production and marketing, abattoir workers, meat workers and handlers.

How is Brucellosis transmitted?

In Australia, the disease is transmitted to people from infected cattle or pigs who usually get the disease by eating contaminated fodder or pasture. The main sources that can transmit infection to workers are foetuses ("slinks"), placenta, birth fluids, joint swellings of infected pregnant cows, udders and milk of infected lactating cows.

Transmission occurs usually by direct skin contact with these animal tissues or by inhalation of infective droplets and dust. The brucella bacteria can penetrate intact skin.

What are the symptoms?

Symptoms of brucellosis can be similar to the common cold. It is characterised by fluctuating fever, headache, sweating, weakness, muscular pains and depression. These signs occur two to four weeks after infection has occurred. These acute symptoms usually lessen within a few weeks but the patient may suffer relapses and can be chronically ill for several years.

Treatment

If the appropriate antibiotic treatment is given by a doctor, recovery from brucellosis is usually prompt; however, relapses may still occur.

What you can do

Due to the non-specific nature of the symptoms, people with brucellosis infection may be misdiagnosed. Occupationally exposed groups, such as abattoir workers, are therefore advised to see a doctor regarding any illness no matter how mild.

It is further recommended that the occupation of the worker is specifically included in their medical record so that zoonoses be considered in any diagnosis. Occupationally exposed groups should have access to specialised medical services that can ensure that a correct and early diagnosis of brucellosis can be made.

Preventing infection

Preventive measures, that are well understood by workers, should be implemented in workplaces to eliminate brucella infection. Some of the control measures recommended by the National Occupational Health and Safety Commission (see Diseases acquired from animals, AGPS 1989) to prevent and manage brucellosis include: