As Water Levels Drop In Central Texas, Incidents Of Rabies Rise

By Brenda Bell

AMERICAN-STATESMAN STAFF

The drought made 2011 a bad year for wildlife in Texas. But it was a bountiful year for rabies, especially in Central Texas. During times of drought as water supplies dry up, more animals congregate at the remaining water sources, making it easier for disease to spread, said health department veterinarians.

Samples of tissue from 1,018 animals tested positive for the disease — the most since 2008, according to statistics kept by the Texas Department of State Health Services. That’s a 30 percent increase over 2010, when Texas had the most cases in the United States.

Last year Central Texas was the epicenter for rabies: Williamson County led the state with 135 cases, followed by Travis County with 59, Burnet County with 57, Hays with 29 and Llano with 26. Bastrop reported 23 cases, the eighth-highest number in the state.

In Travis, Williamson and Hays counties, nearly all the sick animals were bats. Considering the total population of Mexican free-tailed bats is estimated to be in the millions, the rate of infection is “miniscule,” according to the Texas Department of Parks and Wildlife.

Statewide, more than half the rabid animals were skunks; 30 percent were bats. Rabies showed up in 76 domestic animals: 30 cats, nine dogs, 22 horses, 10 cattle, four goats and an alpaca.

“Skunk rabies is our biggest problem and has been,” said Dr. Tom Sidwa, who manages the zoonosis control branch for the Health Department. “Everything that shows up now is either a skunk variant or bat variant.”

An aggressive program of oral rabies vaccine distribution in South Texas and West-Central Texas that began in the mid-1990s is credited with eliminating coyote/dog rabies and fox rabies within the state’s borders, so when those animals get the disease now, it’s a variant from another species. No one has yet figured out how to vaccinate bats, which range far and wide in search of insects, their only food.

But the Health Department is preparing an offensive against skunk rabies, using liquid oral vaccine in bait that’s been taste-tested to attract the omnivorous animals.

Last month, Health Department employees set out baits in various flavors — marshmallow, fish, cheese and egg — at 45 sites in Central Texas where skunks have been reported. The most popular taste will flavor the bait that conceals packets of vaccine.

The Health Department is also the source for most of the vaccine administered to people exposed to rabies in Texas. According to preliminary figures, the department distributed vaccine to 709 people in 2011, compared with 732 in 2010.

Since 1990, there have been eight reported deaths from rabies in Texas: three from contact with bats, two from dog bites and three from organ transplants from an Arkansas man who turned out to have died from rabies. (Organ screening does not routinely test donors for the disease.)

There have been no reported human deaths from rabies in Texas since 2006, when Zach Jones, a high school football player from Humble, contracted the disease from a bat that flew into his room.

His parents established a nonprofit foundation in their only child’s name to promote rabies education and research.