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County Scientists Prepare to Engage Hantavirus : Health: After protective gear arrives, they'll trap and test rural rodents for deadly virus found in five South County deer mice.


GARDEN GROVE — County scientists will order special protective gear today that will allow them to trap and test rural rodents that may be infected with the mysterious, often deadly hantavirus, an official said.

Once armed with the gear, county pest control teams will survey the rodent population at the sprawling TRW Capistrano Test Site near San Clemente within the next three weeks, county vector ecologist Jim Webb said Thursday.

Blood samples from five deer mice captured at three outdoor spots within the 2,770-acre TRW facility tested positive this month for hantavirus, an airborne organism that has been linked to at least 33 deaths nationwide.

"We'll be doing a full county survey, but we'll concentrate initially on the area of the TRW site, and inside their buildings to see if the virus is overlapping into the house mouse population," Webb said. "We'll be looking at several species, but focusing on the deer mice because we know they're hot."

All county surveys of rodent populations were halted last month following a statewide advisory deeming the hantavirus threat too great for field studies. But Webb said the new equipment, which includes respirators, gloves and goggles, would afford enough protection.

State health officials are expected to visit Orange County early next week to help devise safe trapping procedures.

Little is known about the virus, which can lie dormant in the human body for 45 days before striking with flu-like symptoms that rapidly worsen. Once muscle aches, fever and respiratory problems strike, death from fluid-filled lungs can come in days or mere hours. No cure exists.

County officials noted that the hantavirus found in the five Orange County deer mice may be a different, less dangerous strain. And although the samples were taken last year and stored for months, there have been no reported illnesses from the virus in Orange County.

Webb will speak this afternoon to the more than 100 employees at TRW, which borders Camp Pendleton, to explain the virus and safety precautions. Health officials suggest avoiding rural rodents and keeping homes and garages clean of droppings, which should be misted from above with a mixture of bleach and water and wiped. Gloves and dust masks should be worn during cleaning, and a double plastic bag is suggested for disposal.

Two deaths from the virus have been documented in California, the nearest in Santa Barbara County. In both cases, the victims were in close contact with rural rodents on an almost daily basis, a fact that Webb said should be remembered by antsy county residents who have jammed pest control phone lines in recent days.

The deer mouse, which may grow to five inches from nose to tail, can be identified by its rust-brown fur that becomes bright white on its underbelly, snout and feet. It also has fur on its tail. The common house mouse is typically a uniform gray or brown and has a hairless tail.

House mice were identified as carrying the virus in the Four Corners area of northern Arizona and New Mexico, the flash point of the virus this summer, but Webb said it seems unlikely that the hantavirus would be found among rodents in Orange County urban and suburban areas. Indoor rodents at the TRW site will be tested because of their proximity to deer mice, which were captured within several hundred yards of buildings.

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