What is Brucellosis?

Brucellosis is a bacterial disease that is usually transmitted from animals to humans. The infection is most often acquired through the consumption of unpasteurized milk or other contaminated dairy foods and meat. However, it can also be spread through airborne bacteria and direct contact with ailing animals.

Some of the animals that can spread brucellosis are livestock, dogs, buffalo, goats, deer and moose. Although it is rare in the USA, Europe and Canada, it infects countless people annually across the globe. It is rarely spread from humans to other humans even though it can be transmitted through bodily fluids.

What are the Symptoms of Brucellosis?

Early symptoms include

  • Night sweats
  • Chills
  • Severe head pain
  • Aching bones and joints
  • Diarrhea

As the disease progresses symptoms may also include

Brucellosis can cause irreparable damage and result in death if it infects the lining of the heart.  It can also cause testicle infection in males, enlargement of the liver and spleen and potentially deadly central nervous system infections including meningitis. Blood tests may be used to confirm the condition, and other tests may be performed to check for organ damage.

Brucellosis Causes

Brucellosis is a zoonotic bacterial infection, which means that it is passed from animals to humans. Disease researchers have identified eight animal species that can transmit the disease, but the four most common are sheep, pigs, cattle, and dogs. Dogs rarely transmit the disease to their owners, but humans with weak immune systems should avoid contact with infected dogs.

Humans usually become infected with brucellosis by ingesting under-cooked meat or unpasteurized milk and milk products. The bacteria may also be directly inhaled, or can enter the body through the eyes or broken skin.

Some people are at more risk for contracting brucellosis than others. It is more common in areas of the world where domestic animal health programs are not as effective, such as the Mediterranean basin, Eastern Europe, Mexico, and South and Central America. Tourists in developing nations sometimes ingest unpasteurized milk and milk products (called “village cheeses”) accidentally, unaware of the risk.

Meat industry workers, veterinarians, and lab researchers can face high exposure to the bacteria, and are among the most frequently infected.

Hunters can become infected by inhaling the bacteria, exposing open wounds, and ingesting under-cooked meat. Big game animals that can transmit the disease include moose, caribou, and elk.

Person to person transmission of brucellosis is possible but uncommon, with few documented cases of sexual transmission. The highest risk comes from pregnant or nursing mothers who pass the disease on to their infants.

How is Brucellosis Treated?

When treating brucellosis, two antibiotic medications are usually taken in conjunction. Symptoms may also require treatment, and the condition must be monitored since relapse can occur. Although it can go away in just two or three weeks, even without medication, it can take weeks or even months for some to fully recover.

The infection can be difficult to treat, and fever can come and go for years.

Brucellosis can be prevented through livestock vaccinations, by exercising safety precautions when handling or working with live or dead animals, by cooking meat to recommended temperatures and by consuming only pasteurized dairy products.

Brucellosis Prevention

To prevent brucellosis infection, avoid consuming under-cooked meats and unpasteurized milk and milk products, including cheese and ice cream. Do not consume these foods if you are uncertain about how they have been processed, especially when traveling in an unfamiliar area.

Cook all meat thoroughly until it reaches an internal temperature of 145 to 165 F (63 to 74 C). When traveling abroad and ordering at restaurants, request that all meat is well-done.

If you work with animal tissue, wear protective gear such as rubber gloves, aprons, and goggles to prevent exposure to the eyes and skin.

In a laboratory setting or other high-risk industry, strictly follow all safety protocols.

Last Reviewed:
September 13, 2016
Last Updated:
March 30, 2018