Brucella abortus is a bacteria that rarely causes disease in healthy children.  The bacteria comes from cows and can infect children who drink unpasteurized milk.  Undulant fever is the disease caused by Brucella abortus infection in humans.  Fortunately, this infection is rare where there is widespread pasteurization of milk and vaccination of cattle.

 

 

 

Diseases

• Undulant fever - characterized by a flu-like illness and a rising and falling body temperature.

Habitat & Transmission

• Lives in cows. 
• Can be found in unpasteurized milk and cheese. 
• Can survive and replicate within some immune cells. 
• Only rarely can it be transferred from one person to another. 

Weapons/Defenses

• Infects humans by way of ingested milk products or through the skin of meat workers. 
• Uses a toxin to cause a flu-like illness that can progress but usually resolves in a few weeks. 
• Can form an abscess. 
• Can survive and multiply in macrophages after they are swallowed whole.

Weaknesses

• Pasteurizing milk is an effective way to kill Brucella abortus.
• Uncommon in the U.S. thanks to widespread vaccination of cattle. 

Good/Bad

• Brucella abortus is rarely a dangerous disease.
• Will usually be controlled by the immune system within a few weeks or days.
  

Photo - Brucella spp. are gram-negative in their staining morphology. CDC/Courtesy of Larry Stauffer, Oregon State Public Health Laboratory. 2002. Used with permission.