Goat Version Of Bangs Found
In South Texas' Starr County

AUSTIN — A story unfolding in Starr County in South Texas has all the elements of a mystery, including intricate laboratory analyses of blood and tissue samples, and expert detectives trained to track down a dangerous suspect. This, however, isn't a case of murder or mayhem, but of Brucella melitensis, a bacterial disease that can affect human and livestock health, but which hasn't been diagnosed in Texas for a quarter century.

Disease detectives, or epidemiologists, are attempting to pinpoint how a South Texas goat herd became infected with Brucella melitensis, a form of brucellosis (historically called "Malta Fever") that is associated with

goats. The epidemiologists are also trying to determine if, or where, the bacterial disease may have spread. Meanwhile, to prevent a risk to human or livestock health, the herd of nearly 120 goats and sheep has been

depopulated and buried by veterinarians and animal health inspectors from the Texas Animal Health Commission, with assistance and resources supplied by the U.S. Department of Agriculture's Veterinary Services.

"We're particularly concerned about Brucella melitensis, as it can cause serious illness in humans, if they consume unpasteurized milk, cheese (milk products) or process the meat from an infected goat without taking

precautions. We're urging South Texas ranchers to have their goats tested for the disease, particularly if they are planning to use milk from the nannies, or slaughter the animals," said veterinarian Terry Conger, TAHC's state epidemiologist. He noted that ranchers also should bring only tested goats into their herds, whether the additions are strays or acquired by purchase, trade, or as a gift.

For more information on having goats tested, producers can contact their private veterinary practitioners, their TAHC area office, or the TAHC's Austin headquarters at (800) 550-8242, ext. 712.

Dr. Conger also pointed out that the Texas Department of Health has notified physicians and public health clinics in South Texas to be alert for patients who may have contracted this form of brucellosis, which in humans is also known as "undulant fever." The disease can be spread to humans through contact with infected goats, unpasteurized goat milk, cheese or raw goat meat products. Sufferers may experience flu-like symptoms, such as night sweats, aches and pains, headache, loss of appetite, and a fever that comes and goes throughout the day. A simple blood test can be used to diagnose the disease, but a physician's care and antibiotics are necessary to treat the disease and prevent serious complications that can result from infection, he said.

"Mexico reported 6500 cases of undulant fever in humans in l998, many of which can be attributed to infected goats," said Dr. Conger. "The Texas Department of Health recorded 16 cases in our state. Fourteen of the patients had consumed goat dairy products, and nine of the group had also traveled internationally. We want to ensure that producers and consumers are not put at risk by a disease that can be prevented or treated."

To avoid risk of human disease, Conger repeated that goats should be tested before they are milked or processed for meat. Cooked meat is safe to eat, as heat kills the Brucella melitensis bacteria. However, if ranchers are slaughtering untested goats, they should wear a face mask, glasses and rubber gloves, to prevent the possibility of breathing in or otherwise exposing themselves to the bacteria that can become airborne during the slaughtering process. Clothing should be laundered after the processor has completed the task.

Conger pointed out that the infected goat herd probably would have gone unnoticed for some time, if a neighboring rancher had not sold a cow to slaughter in late summer. Like all adult cattle moving through a livestock

market, a routine blood sample was collected to test the cow for bovine brucellosis, which usually affects cattle, and is a disease which the country's livestock industry has worked to eradicate for more than 50 years. Texas, one of six states that hasn't yet eliminated the disease, has

two known infected cattle herds currently under quarantine.

"We were concerned, but not alarmed when the cow tested positive on the two brucellosis 'field' tests at the livestock market, because we were looking for cattle brucellosis," said Conger. "Additional blood samples were

collected from the cow for laboratory testing, then the animal was identified as being infected and was shipped to slaughter. At the processing plant, tissues also were collected from the cow for other extensive tests."

In the Austin State-Federal Laboratory, which is operated jointly by the TAHC and the U.S. Department of Agriculture, test results on the cow's blood and tissues were "atypical." Samples were forwarded to USDA's

National Veterinary Services Laboratory in Ames, Iowa, where the bacteria was confirmed as Brucella melitensis, the goat form of the disease that had not been seen in Texas for 25 years.

"We moved quickly to spread the net to find the source of this cow's infection," said Conger. "We tested the remaining animals in the rancher's cattle herd and found four other animals that carried a low 'titer,' indicating they likely have been exposed to melitensis. These cattle were depopulated and buried, to protect workers who might be exposed to airborne bacteria when handling infected carcasses at the slaughter plant. The remaining disease-free cattle in the herd were shipped to slaughter, as they could be slaughtered without risk to human health.

"We also tested other susceptible species of animals, including dogs, horses, cattle and goat herds, and flocks of sheep on that site and on 10 surrounding ranches, without finding any additional infected animals. We

broadened the search, and a little more than a quarter-mile from the cattle herd, the infected goat herd was detected. Through our epidemiological investigation, we've learned that the cattle rancher in the past had purchased cattle from the goat herd owner. That could have been the portal

for introducing the disease from the goats to the cattle herd."

Conger said that, for each answer in this disease investigation, an additional question arises, including:

— How did the flock of goats become infected? Conger said widespread herd testing in the area will continue in the effort to answer this question. Thorough herd records were not maintained on goats bought and sold, so tracing all animal movement into and out of the infected herd

will be very difficult. "That's why we want to encourage ranchers to have goats tested, particularly if the animals live in or originated in the South Texas area," said Conger.

Ranchers whose livestock or dogs are within the targeted test zone near the infected goat herd have been contacted and their animals have been tested by TAHC veterinarians and inspectors.

— Why didn't the disease spread to animals that had fence-to-fence contact with the infected goat or cattle herd? Conger said Brucella melitensis causes nannies to abort one time. Animals that come in contact with the

bacteria-laden aborted fetus can become infected. After the initial "abortion storm," however, affected goats will not lose fetuses, even though they will carry the disease for a lifetime, he said. The bacteria is shed through milk, on newly born kids, and in afterbirth, all products that pose greater threat to ranchers than to nearby animals.

Conger said ranchers should protect human and livestock health by bringing in only tested goats, testing goats before consuming products from the animals, and by maintaining records on animals bought and sold.

"Carefully maintained records can save time and help unravel mysteries when an infection like this occurs," he said. "We have proven tools to protect human and livestock health; now we must ensure they're put to good use while we continue to look for the source of this disease incident."