The U.S. Department of Agriculture has announced that for the first time in the 74-year history of the brucellosis program, all 50 states, Puerto Rico and the Virgin Islands have simultaneously achieved Class Free status. Texas is the last and final state to be declared brucellosis free.

"This tremendous achievement could not have been accomplished without the combined efforts of state and federal agencies and industry," said Bruce Knight, under secretary for USDA's marketing and regulatory programs mission area. "But our work is not done. We must now focus our efforts on eradicating brucellosis from the free-ranging elk and bison populations in the Greater Yellowstone Area in order to protect our national cattle herd against future outbreaks of this disease."

Class Free status is based on a state finding no known brucellosis in cattle for the 12 months preceding designation as Class Free. A state's Class Free status, however, can change. If brucellosis is found in more than one herd of cattle in a brucellosis free state within a two-year period, the state is downgraded to Class A status.

The presence of brucellosis in free-ranging bison and elk in Yellowstone National Park and Grand Teton National Park still threatens the brucellosis status of surrounding states. In May 2007, Montana discovered brucellosis in a herd of cattle, potentially jeopardizing its free status.

The classifications for brucellosis are as follows: Class Free, Class A, Class B and Class C. Restrictions on the interstate movement of cattle become less stringent as a state approaches or achieves Class Free status. The Class C designation is for states or areas with the highest rate of brucellosis. States or areas that do not meet the minimum standards for Class C are required to be placed under federal quarantine.

In 1934, the eradication of brucellosis was elevated to a national scale with the formation of a cooperative state–federal brucellosis eradication program to eliminate brucellosis from the country. Brucellosis is a bacterial disease that causes decreased milk production, weight loss, infertility, loss of young and lameness in cattle, elk and bison. The disease is contagious and can, though rarely, affect humans. There is no known treatment for brucellosis, and depopulation of infected and exposed animals is the only effective means of disease containment and eradication.