Transmission

Humans are generally infected with brucellosis in one of three ways:

Eating undercooked meat or consuming unpasteurized/raw dairy products

The most common way to be infected is by eating or drinking unpasteurized/raw dairy products. When sheep, goats, cows, or camels are infected, their milk becomes contaminated with the bacteria.
If the milk from infected animals is not pasteurized, the infection will be transmitted to people who consume the milk and/or cheese products.

Breathing in the bacteria that cause brucellosis (inhalation)

Breathing in the bacteria that causes brucellosis may also lead to infection. This risk is generally greater for people in laboratories that work with the bacteria. In addition, slaughterhouse and meat-packing employees have also been known to be exposed to the bacteria and ultimately become infected.

Bacteria entering the body through skin wounds or mucous membranes

Bacteria can also enter wounds in the skin/mucous membranes through contact with infected animals.
This poses a problem for workers who have close contact with animals or animal excretions (newborn animals, fetuses, and excretions that may result from birth). Such workers may include:

• slaughterhouse workers
• meat-packing plant employees
• veterinarians

People who hunt animals may also be at risk. When they are in contact with infected animals, exposure to the bacteria may occur through:

• skin wounds
• accidentally ingesting undercooked meat
• inhaling the bacteria while dressing their game. Commonly infected animals include: bison, elk, caribou, moose and wild hogs (feral swine).

Person-to-person spread of brucellosis is extremely rare. Infected mothers who are breast-feeding may transmit the infection to their infants. Sexual transmission has been rarely reported. While uncommon, transmission may also occur via tissue transplantation or blood transfusions.

Signs and Symptoms

Brucellosis can cause of range of signs and symptoms, some of which may present for prolonged periods of time.
Initial symptoms can include:

Some signs and symptoms may persist for longer periods of time. Others may never go away or reoccur.
These can include:

Risk of Exposure

Anyone who is exposed to the bacteria that cause brucellosis is at risk for infection. Some people, based on certain circumstances, may face an increased risk. Below, learn more about specific risks related to brucellosis.

Areas at risk
Learn about the places around the world where brucellosis is most commonly found.

 

Risks from unpasteurized dairy products
Learn about the risk from unpasteurized milk and dairy products.

 

Occupational risks
Learn which occupations or work settings may increase the risk of brucellosis.

 

Risks for expecting mothers
Expecting mothers can learn how to keep their baby safe when at risk for brucellosis.

 

Three types of the bacteria that cause brucellosis – Brucella abortus, Brucella melitensis andBrucella suis – are designated as select agents. This means that they have the potential to be developed as bioterrorism agents due to their ability to undergo aerosolization.

Treatment

Generally, the antibiotics doxycycline and rifampin are recommended in combination for a minimum of 6-8 weeks. Let your doctor know if you are:

• pregnant
• allergic to doxycycline or rifampin
• suffer from a reduced or absent immune response (immunosuppressed)

Before treatment begins, a diagnosis of brucellosis infection must be made by a doctor.
Tests will be performed to look for bacteria in samples of blood, bone marrow, or other body fluids. In addition, a blood test can be performed to detect antibodies against the bacteria.
Once a diagnosis is made, a doctor can prescribe antibiotics.
Depending on the timing of treatment and severity of illness, recovery may take a few weeks to several months. Death from brucellosis is rare, occurring in no more than 2% of all cases.

Prevention

The best way to prevent brucellosis infection is to be sure you do not consume:

• undercooked meat

• milk

Pasteurization is when raw milk is heated to a high temperature for a short period of time. This heating process destroys harmful bacteria that may make the milk unsafe to consume.
If you are not sure that the dairy product is pasteurized, do not eat it.
People who handle animal tissues (such as hunters and animal herdsman) should protect themselves by using:

This will help ensure that bacteria from potentially infected animals do not get into eyes or inside a cut or abrasion on the skin.