Public health priority: Routine.
PHU response time: Respond to confirmed and probable cases within 3 working days. Enter confirmed and probable cases on NCIMS within 5 working days.
Case management: Case should receive appropriate antibiotics. Identify source and if from Australian animals or their products, report to CDB on same day.
Contact management: None
Confirmed and probable cases should be notified.
A confirmed case requires laboratory definitive evidence only.
* It is important to note that serological testing for brucellosis cannot determine the species of Brucella.
A probable case requires laboratory suggestive and clinical evidence.
A clinically compatible illness.
Brucellosis is to be notified by laboratories on microbiological confirmation (ideal reporting by routine mail).
Confirmed and probable cases should be entered onto NCIMS.
Brucella species is an important bacterial zoonosis caused by members of the genus Brucella. Although found worldwide it is well controlled in most developed countries.
Different species of Brucella infect different preferred animal species, although infection can occur in animals other than the preferred host. There are five Brucella species that are known to cause human brucellosis.
Although Brucella ovis is present in many sheep flocks across NSW, it is not known to cause human disease. Brucella neotomae and Brucella suis (biovar 5) are found in rodents. They are not known to cause human disease nor have they been described in Australia.
Brucellosis is an infection primarily of animals that causes infertility and late-term abortion. Rarely, brucellosis occurs in humans as a zoonosis causing a broad spectrum of symptoms. The ultimate control of human brucellosis will depend on the elimination of the disease in animals; therefore human cases may act as a marker of animal disease.
Brucella bacteria are found in the blood, urine, semen, vaginal discharges, placentas, milk and aborted foetuses of infected animals. It may also be found in the saliva, and nasal, ocular and joint fluids of infected animals.
Humans usually become exposed by contact with bacteria contaminated fluids from infected animals through abraded skin or mucous membranes or by ingestion of infected animal products. In laboratories and during butchering of infected animals, Brucella may be transmitted in aerosols. It can also be transmitted on fomites as it withstands drying and can survive in contaminated dust and soil. Survival may be prolonged in conditions of low temperature, high humidity and no sunlight. Brucella species are also considered potential bioterrorism agents.
Person-to-person transmission of brucellosis is very rare. Congenital infection may occur through the placenta, during breast feeding or due to contact with the mother's blood, urine or faeces during delivery. There have also been rare reports of transmission after blood transfusions, bone marrow transplant and sexual contact.
Live animal vaccines for brucellosis are known to be pathogenic to humans however they are not currently in use in Australia.
The typical incubation period is difficult to determine, probably 5 to 60 days, but more commonly 30 to 60 days. The incubation period may be shorter if the bacteria have been aerosolised for use as a biological weapon.
Brucellosis typically begins with acute non-specific flu-like symptoms. These may include fever, headache, weakness, profuse sweating, chills, weight loss, joint pain, muscle pain, and generalised aches.
Inflammation of the liver and spleen, and gastrointestinal or respiratory signs may occur. In males, the testicles and epididymis may become inflamed. Suppurative infections of organs and osteoarticular complications may also occur. Where endocarditis occurs, there is a high case-fatality rate.
Typically symptoms last for 2-4 weeks and are followed by a spontaneous recovery. Some infected people may develop an intermittent fever and other symptoms that wax and wane at 2-14 day intervals, known as 'undulant fever'. Occasionally symptoms last for a year or more, patients may become chronically ill and symptoms may recur even after successful treatment.
Within 3 working days of notification begin follow-up investigation. Where transmission from Australian animals or their products is suspected, notify the Senior Animal Health Officer, NSW Department of Primary Industries (DPI; from the likely source area) and CDB on the same day. The public health unit will work closely with the NSW DPI to try and identify and control the likely source of infection in appropriate.
Within 5 working days of notification enter confirmed and probable cases on NCIMS.
The response to a notification will normally be carried out in collaboration with the case's health carers. But regardless of who does the follow-up, PHU staff should ensure that action has been taken to:
Effective treatment usually involves a combination of antibiotics for at least six weeks. Occasionally, antibiotics may need to be continued for months. Despite effective treatment brucellosis can recur, therefore it is important to encourage the case to seek medical assistance if symptoms persist or recur. See the latest edition of the Therapeutic Guidelines: Antibiotic.
The case or relevant care-giver should be informed about the nature of the infection and the mode of transmission. In particular, emphasis should be placed on careful handling of feral pig carcasses if B. suis infection is suspected.
When in direct contact with animals:
Further information can be obtained from the NSW DPI Brucellosis in dogs information sheet (see also Section 6 - Managing special situations).
People travelling overseas should avoid eating or drinking unpasteurised dairy products like milk or cheese. Raw milk can be boiled before consumption if pasteurisation is not available.
Determine the likely mode of transmission by asking about the following in the two months prior to the onset of illness:
If brucellosis is acquired in NSW, the NSW DPI should always be consulted and an environmental evaluation may be conducted if deemed necessary.
Contacts are those who may have been exposed to the same source as the case. Identify possible cases among co-exposed persons, provide them with information about the disease, and advise to seek medical attention should symptoms develop.
Brucellosis is a notifiable condition in animals under the Animal Diseases and Animal Pests Act 1991. The NSW DPI will contact the Communicable Disease Branch concerning a positive finding of brucellosis in a dog. The public health unit will be notified by the NSW DPI or Communicable Disease Branch.
NSW DPI will liaise with the treating veterinarian and if necessary the dog owner and provide a copy of the NSW DPI Brucellosis in dogs information sheet. This includes guidance and recommendations on the prevention, diagnosis and management of the infection in dogs, including that:
This information sheet also includes information on the risk to human health. The veterinarian and dog owner will be provided with the local public health unit contact number and instructed to call if they have any questions concerning risk to human health.
For NSW Health factsheets on brucellosis in humans, see the:
For further information about brucellosis in animals, see the NSW DPI webpages on: