Gear for Field Search of Hantavirus Specimens Is Tested : Health: Equipment will be worn by scientists near San Clemente as they study biological agent that is spread by fine dust from deer mice droppings.

Encumbered by a leaky respirator, foggy goggles and bulky gloves, Steven Bennett looked far from daunting Thursday as he demonstrated how he plans to hunt down the often-fatal hantavirus, which was discovered recently in several Orange County rodents.

Bennett, a county assistant vector ecologist, walked--sometimes stumbled--through the demonstration before representatives of area vector-control agencies and extermination companies.

“We never rehearsed going through that,” said Bennett, who teamed up with fellow vector ecologist Jim Webb. “We made a lot of mistakes.”

The demonstration showed just one of the difficulties facing county scientists as they prepare for field tests they hope will define the character of the mysterious hantavirus, which is spread by a fine dust emitted by deer mice droppings.

In two to three weeks Bennett, Webb and other scientists will set off for the TRW Capistrano Test Site near San Clemente to trap deer mice. There, they will take blood samples and preserve mouse carcasses for tests to be conducted by the Centers for Disease Control and Prevention in Atlanta.

In their field work, the local scientists will don the protective gear to shield them from the potentially lethal dust.

It was near the sprawling, 2,770-acre TRW site where five deer mice were trapped last year in a routine rodent survey. Tests of the mices’ stored blood samples in September found evidence of the hantavirus, an organism linked to at least 33 deaths nationwide.

Trapping rodents is something Bennett does all the time in his work. But he concedes he’s never had to go through all the motions that will be involved in the field study, especially when encased in bulky gear.

Part of the problem Thursday, Bennett said, was that county scientists are still experimenting with the equipment they plan to use.

“It was a pain,” he said. “It was bulky and hot and sweaty. My goggles were fogging up, my mask was leaking air on the side and you’re worrying about contamination. . . .”

They also need some rehearsal time to choreograph their maneuvers in retrieving traps, killing the mice, drawing blood and preserving the remains in dry ice, he said. Usually, much of that work is done in a laboratory. But it will be done in the field in this case because of the high risk of contamination.

To practice, Bennett said, “we’ll get the proper stuff, get set up in the lab and make a list of what we should be doing. Doing (tests) in the field is going to take a lot more organization.”

Webb said county scientists, who are being assisted by state health officials, will likely replace the respirator and goggles with a full-face, hard-plastic mask into which filtered air is pumped. They’ll also don two layers of surgical gloves and a protective smock.