Brucellosis is an infectious disease caused by bacteria (Brucella species). The most common ways people acquire the disease is by consuming undercooked meat or unpasteurized dairy products, breathing in bacteria, or entry through a wound after touching an infected animal. Animals that are most commonly infected include sheep, cattle, goats, pigs and dogs.
Tularemia is a disease of animals and humans caused by the bacterium Francisella tularensis. Humans can become infected through tick and deer fly bites, skin contact with infected animals, drinking contaminated water, or breathing in contaminated aerosols or agricultural dusts.
When the human body is invaded by disease-causing organisms such as bacteria, it responds in several ways to combat the invader. One response is in the production of antibodies by the body. The Vermont Department of Health Laboratory performs agglutination tests to detect Brucella or Francisella antibodies in blood serum specimens.
For the optimal test interpretation, two serum specimens should be submitted. The first specimen should be collected while the patient is exhibiting symptoms. The second should be collected two to three weeks later. A significant increase in the antibody level between the two specimens could indicate an exposure to Brucella or Francisella.
More information from the Health Department on Francisella
More information from the CDC on Brucellosis