Brucellosis is caused by the bacterium Brucella. This bacterium infects domesticated animals. It can be spread to humans through:
- Drinking unpasteurized milk from infected cows, sheep, or goats
- Eating dairy foods from infected cows, sheep, or goats
- Inhaling the bacteria
- Breastfeeding—passed from an infected mother to an infant
- Sexual transmission
- Tissue transplantation
Factors that increase your risk of getting brucellosis include:
- Working with domesticated animals and livestock, especially sheep, goats, cattle, deer, elk, and pigs, or their waste products, bodily fluids, or carcasses
- Eating undercooked meat products
- Living in or travel to high-risk areas
- Sex: male, possibly due to occupational exposure among farmers, ranchers, veterinarians, people working in tanneries, and slaughterhouse workers
Symptoms of brucellosis usually appear within two weeks of infection. Symptoms can appear from five days to several months after infection.
In the early stage, symptoms may include:
- Muscle pain
- Severe headache and backache
- Nausea, vomiting, and diarrhea
- Abdominal fullness or discomfort
- Joint pain
As it progresses, brucellosis causes a high fever (104° F to 105° F). This fever occurs in the evening along with severe sweating. It becomes normal or near normal in the morning, and usually begins again at night.
This on and off fever usually lasts 1 to 5 weeks. After 5 weeks, symptoms usually improve or disappear for two days to two weeks. Then, the fever returns. In some patients, this fever returns only once. In others, the disease becomes chronic, and the fever returns, lessens, and then returns again over months or years.
In later stages, brucellosis can cause:
- Loss of appetite
- Weight loss
- Abdominal pain
- Joint pain
Patients usually recover within 2 to 5 weeks. Rarely, complications can develop. These may include:
- Abscesses within the liver or spleen
- Enlargement of the liver, spleen, or lymph nodes
- Inflammation and infection of organs in the body, such as:
- Scrotal swelling
Brucellosis is also believed to cause a high rate of miscarriage during early pregnancy in infected women.
Your doctor will ask about your symptoms and medical history. A physical exam will be done.
Your doctor may need to test your bodily fluids. This can be done with:
- Blood tests
- Urine tests
- Bone marrow tests
- Spinal fluid tests
- Tissue tests
Your doctor may need pictures of your bodily structures. This can be done with:
Many patients recover from brucellosis on their own. However, early diagnosis and treatment can reduce the risk of complications and infection. Talk with your doctor about the best treatment plan for you. Treatment options include:
Your doctor may prescribe one or more antibiotics to control and prevent brucellosis. Antibiotics are given for up to six weeks.
Surgery may be needed in patients with abscesses or an infection that does not respond to antibiotics.
To help reduce your chances of getting brucellosis, take the following steps:
- Avoid eating or drinking unpasteurized milk and dairy foods. If you are unsure if a dairy product is pasteurized, don’t eat it.
- Wear rubber gloves and goggles, and securely cover open wounds when handling domesticated animals including their fluids, waste products, or carcasses.
- Wear a protective mask when dealing with brucellosis cultures in a laboratory.
- Have cattle and bison that live in areas heavily infected with brucellosis vaccinated by an accredited veterinarian or government health official. The vaccine contains a live virus and is dangerous to humans. For best results, calves should be vaccinated when they are 4-6 months old. There is no brucellosis vaccine for humans as of yet.
- Reviewer: Michael Woods, MD
- Review Date: 08/2013 -
- Update Date: 05/11/2013 -