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Brucellosis Battle Continues In State
By Allison Powe
MISSISSIPPI STATE -- Mississippi's fight against brucellosis has been a long, hard struggle, yet despite many setbacks, the state's cattle industry continues to strive for a brucellosis-free status.
A bacterial disease that causes cows to miscarry their calves or become infertile, brucellosis can be contracted by horses, dogs, sheep, goats and swine. Humans also are susceptible to a form of brucellosis, commonly referred to as undulant fever, which causes persistent flu-like symptoms.
In the past, infected humans typically got brucellosis by drinking raw milk or handling animal organs without protective gloves. Immune-suppressed individuals were more likely to be victims of the disease. Today veterinarians and farmers are the most common people to contract brucellosis, which is not fatal.
Dr. Frank Rogers, state veterinarian and director of the state diagnostic laboratory in Jackson, said tests show that Mississippi is free of brucellosis in all species except dogs and cattle.
"The current program that Mississippi employs to eliminate brucellosis started in 1982, when 1,082 herds were quarantined in the state because of the disease. The number of infected herds has steadily decreased," Rogers said.
Mississippi attained the status of an "A" classified state in 1992, which means that less than 0.25 percent of the total cattle population is infected. Since then, Mississippi cattle producers have been striving to gain a brucellosis-free status.
"Every herd in the state must remain free of the disease for 12 consecutive months to achieve the free status," Rogers said.
"For 10 months, from May of 1996, no infected cattle were found in Mississippi until one herd tested positive for brucellosis in Marion County in March. Those cattle were traced to Alabama and Texas, and the herd was depopulated," Rogers said.
Brucellosis-free status remains an optimistic goal, but the 12 month countdown to be classified as a free state had to start over with the discovery of the infected herd.
"Over the years, brucellosis has been a very expensive disease for Mississippi. Not only does it cause a reduction in the number of calves born, it also causes a decrease in milk production and extended calving intervals. We lose money from each of those symptoms," Rogers said.
Dr. Richard Hopper, extension leader of veterinary medicine at Mississippi State University, said the brucellosis-free status will be difficult to earn and maintain.
All incoming cattle must test negative before they enter the state. Cattle are monitored by blood tests administered at stock yards, which are screened during sales and retested in the state laboratory. Infected cattle are traced by the Department of Agriculture and Commerce to identify problem areas.
"A new vaccine has been developed that gives us hope that brucellosis will be easier to contain," Hopper said. Heifers between the ages of 4 and 8 months are vaccinated.
"The state of Mississippi pays to have cows vaccinated on farms. Any owner can have a veterinarian come out to the herd and vaccinate them, and the state will pay for it," Rogers said. Vaccinations are not mandatory because there is little, if any, brucellosis left in Mississippi.
About 38 states have brucellosis-free status and 12 states have the "A" classification, some of which are expected to achieve free status in the next several months. Cooperative efforts of people associated with both the dairy and beef industries throughout the country have improved the health of the nation's cattle over the years.
"Nationally, we hope to be through with this disease by the end of 1998," Rogers said.