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Brucella species bacteria - positive gram stain


What is Brucellosis and How do People Get it?

Brucellosis is a potentially serious illness that may affect one part or several different parts of the body. It is caused by several different bacteria from the Brucella family.


Brucella bacteria are found naturally in some animals including sheep, goats, cattle, deer, elk, pigs, and dogs.


Brucellosis disease in humans is not common in the United States or in California, though it does occur.


During the period 1994-2003 there were 275 total brucellosis illnesses reported in California; of these 2 were in San Francisco. Human brucellosis cases are more common in regions without strong animal disease control programs, including the Middle East and Mediterranean regions, and in China, India, and Latin America.


People can get brucellosis by touching, eating, drinking, or breathing in Brucella bacteria. This is called exposure to brucellosis. Not everybody who is exposed to brucellosis will get sick. But many will, and as the Brucella bacteria multiply inside the body, they can cause serious illness.


Someone can get exposed to naturally-occurring brucellosis by:

  • Touching the hair, skin, or meat of an infected animal
  • Drinking raw or unpasteurized milk or eating raw milk products such as queso fresco that are contaminated with Brucella bacteria
  • Breathing air contaminated with Brucella bacteria (especially farmers or meat workers)

Terrorists could use Brucella bacteria to hurt people on purpose by releasing the bacteria in public places.

What if there is a Brucellosis Emergency in San Francisco?

The San Francisco Department of Public Health (SFDPH) has a plan to respond quickly to a brucellosis emergency. SFDPH will evaluate the brucellosis situation and may recommend ways for people to keep themselves and their family safe. Recommendations may include antibiotics for people who are at risk of illness. SFDPH will also participate in efforts to provide needed medical support and treatment, and to reduce any ongoing sources of Brucella bacteria.


How can I keep from Getting Brucellosis?

People at higher risk for getting brucellosis from a natural source include: farmers, butchers, hunters, and veterinary staff. To lower your risk of getting brucellosis from a natural source:

  • Avoid eating or drinking unpasteurized milk, cheese, or ice cream (including queso fresco). Check the label to make sure it says "pasteurized" and don't eat it if you aren't sure.
  • Do not handle sick or dead animal bodies. But if you must, then use gloves plus face and eye protection.
  • Cook meat thoroughly.
  • It is always a good idea to wash your hands regularly and avoid touching your eyes, nose, and mouth.

If terrorists release Brucella bacteria on purpose, check for recommendations from SFDPH. For example, you may be asked to wash your skin and hair thoroughly and to remove and wash clothing that may have been contaminated.


Can Medicine or a Vaccine (shot) Prevent Brucellosis?

A number of antibiotics have been studied for their ability to prevent brucellosis disease. These medicines work best when you start taking them as soon as possible after an exposure to Brucella bacteria. In an emergency involving brucellosis, SFDPH will offer guidance about which antibiotics to take, who should take them, how and where you can get them, and how to take the medicines.


There is no vaccine for brucellosis.

Can I catch Brucellosis from Someone?

It is very unlikely. Brucellosis is not spread from person-to-person except in very rare cases. There have been a few cases where a person who was sick with brucellosis spread the disease to another person through unprotected sexual contact or from mother-to-child contact (through breastfeeding or giving birth).

What are the Signs of Brucellosis?

Brucellosis often looks like other, more common illnesses. Signs of brucellosis may include fever, sweats, headaches, back pain, and physical weakness. Severe infections of the brain, spinal cord, or lining of the heart may occur. Brucellosis can cause long-lasting or chronic symptoms that include fevers, joint pain, and physical weakness.


After exposure to Brucella bacteria, illness typically starts in 1-3 weeks, but it may take quite a bit longer.


See a doctor right away if you are having the signs listed above AND you think you may have been exposed to Brucella bacteria. It is important to start medical treatment as soon as possible.


Is there Treatment for Brucellosis?

Yes, but the treatment can be long and difficult. Doctors can prescribe antibiotics; usually combination antibiotics are used for at least several weeks to treat the infection and prevent it from coming back. It may take up to several months for someone to recover, even with treatment.


How can I find Information during a Brucellosis Emergency?

Check the SFDPH website Local media such as newspapers, TV stations and radio will carry emergency instructions. Emergency radio stations include: KCBS 740 AM and KGO 810 AM.

What can I do Now if I am worried about Brucellosis?

  • Read about brucellosis at and at the Centers for Disease Control-Emergency Preparedness page
  • Go to to learn about steps you can take now to prepare for all disasters.
  • Keep a card in your wallet with a list of your health problems, the names and doses of medicines you take, and any medicines you are allergic to.

Additional Information

  • Information on Brucellosis for Health Care Providers
    • Brucellosis is a CDC Bioterrorism Category B agent.
    • Reporting: a suspected or confirmed case must be reported immediately (within one hour) to SFDPH by calling (415) 554-2830. Click here for more reporting information.
    • Documents:
      • "Infectious Disease Emergencies: A Preparedness and Response Guide for San Francisco Clinicians"

Useful Brucellosis Links

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