REGION: Snakebites becoming more toxic

UCSD issues caution about rattlers

By GARY WARTH - Staff Writer | Monday, June 9, 2008 5:34 PM PDT ∞

SAN DIEGO ---- Rattlesnakes are packing more of a punch in California and two other states these days, and the more toxic bites may be connected with some deaths in Arizona.

"Our victims are showing symptoms of severe weakness, trouble breathing and low blood pressure this year," said Dr. Richard Clark, director of the division of medical toxicology at UC San Diego.

Clark, medical director for the San Diego division of the California Poison Control System at the UCSD Medical Center, said this is the second straight year the center's toxicologist has reported extreme reactions and unusually powerful bites from Southern Pacific rattlesnakes.

Toxicologists in Arizona and Colorado also have reported seeing extreme symptoms due to rattlesnake bites, and a higher level of toxicity may have contributed to an increase in fatal bites.

Five people have died from rattlesnake bites in Arizona since 2002, with three or four of them from extreme symptoms, said Steve Curry, director of medical toxicology at the Banner Poison Control Center in Phoenix. Curry could recall only five fatal rattlesnake bites in the two decades before 2002.

The number of reported snake bites in San Diego County has increased each year, and the California Poison Control System has reported at least a dozen since January, according to the UCSD Medical Center.

Clark said toxin levels in rattlesnakes vary from year to year and season to season, with the bites typically stronger in summer when the snakes are more active, but he has no explanation about why the toxin levels are increasing.

"We really don't know why the venom is becoming increasingly potent," Clark said in a prepared statement. "Some speculate that with the modern world encroaching on nature, it could be survival of the fittest. Perhaps only the strongest survive. UC San Diego will be conducting clinical trails later this summer with a new antivenin for rattlesnake bites."

"This is a brand-new phenomenon," said Jeffrey Brent, clinical professor of medicine at the University of Colorado Health Sciences Center. "It should spur a considerable amount of research in the area."

Brent said he hadn't seen the extreme symptoms in patients until last year, when there were five. "They came pretty darn close to dying," he said. "They were extremely, extremely sick."

Symptoms of snake bites can include extreme pain, nausea, diarrhea and a swelling in the mouth and throat that makes it difficult to breathe. Victims can become light-headed within minutes, collapse and go into shock.

While not every rattlesnake injects venom when they strike, Clark said it is best for victims to play it safe and seek treatment immediately for any bite.

Administering antivenin is more effective than applying ice, using a tourniquet or applying suction to the wound, which may cause more injury, according to the UCSD Medical Center.

If a victim is in a remote area, the medical center advises the victim to immobilize the wounded area, especially if it is a hand or arm bite, and to move slowly to keep the heart rate low.

Victims should phone for help and only drive themselves to a hospital if no phone is available.

In Arizona, Curry said those who haven't died from the extreme symptoms become critically ill and often take months to recover.

Some suffer severe shock, have strokes, kidney failure or lose some intestines because of impaired blood flow, he said.

"These are things that we did not see at all in years past, but now we see them a few times each summer," Curry said.

In each state, the snakes responsible for the bites have been different. It's the Southern Pacific rattlesnake in California, the prairie rattlesnake in Colorado and the Mojave in Arizona.

In letters last week, Arizona authorities notified hundreds of physicians and emergency rooms of the extreme symptoms, which can be mistaken for other ailments and delay the injection of antivenin. Colorado and California authorities say they're taking a wait-and-see approach to the situation.

The Associated Press contributed to this article.

Contact staff writer Gary Warth at (760) 740-5410 or gwarth@nctimes.com.