Brucellosis
DEFINITION
Brucellosis is a bacterial infection that spreads from animals to people — most often via unpasteurized milk, cheese and other dairy products. More rarely, the bacteria that cause brucellosis can spread through the air or through direct contact with infected animals.
Brucellosis symptoms may include fever, joint pain and fatigue. The infection can usually be treated successfully with antibiotics. Treatment takes several weeks to months, however, and relapses are common.
While brucellosis is uncommon in the United States, the disease affects hundreds of thousands of people and animals worldwide. Avoiding unpasteurized dairy products and taking precautions when working with animals or in a laboratory can help prevent brucellosis.
CAUSES
Brucellosis affects many wild and domestic animals. Cattle, goats, sheep, pigs, dogs, camels, wild boar and reindeer are especially prone to the disease. A form of brucellosis also affects harbor seals, porpoises and certain whales. The bacteria may be spread from animals to people in three main ways:
- Raw dairy products. Brucella bacteria in the milk of infected animals can spread to humans in unpasteurized milk, ice cream, butter and cheeses. The bacteria can also be transmitted in raw or undercooked meat from infected animals.
- Inhalation. Brucella bacteria spread easily in the air. Farmers, laboratory technicians and slaughterhouse workers can inhale the bacteria.
- Direct contact. Bacteria in the blood, semen or placenta of an infected animal can enter your bloodstream through a cut or other wound. Because normal contact with animals — touching, brushing or playing — doesn’t cause infection, people rarely get brucellosis from their pets. Even so, people with weakened immune systems should avoid handling dogs known to have the disease.
- Brucellosis normally doesn’t spread from person to person, but in a few cases, women have passed the disease to their infants during birth or through their breast milk. Rarely, brucellosis may spread through sexual activity or through contaminated blood or bone marrow transfusions.
SYMPTOMS
Symptoms of brucellosis may show up anytime from a few days to a few months after you’re infected. Signs and symptoms are similar to those of the flu and include:
- Fever
- Chills
- Sweats
- Weakness
- Fatigue
- Joint, muscle and back pain
- Headache
Brucellosis symptoms may disappear for weeks or months and then return. In some people, brucellosis becomes chronic, with symptoms persisting for years, even after treatment. Long-term signs and symptoms include fatigue, fevers, arthritis and spondylitis — an inflammatory arthritis that affects the spine and adjacent joints.
When to see a doctor
Brucellosis can be hard to identify, especially in the early stages, when it often resembles many other conditions, such as the flu. See your doctor if you develop a rapidly rising fever, muscle aches or unusual weakness and have any risk factors for the disease, or if you have a persistent fever.
