Blood from a wild sparrow caught at the Maui airport last week tested positive for the virus in preliminary results, but confirmation won't be available until later this week, said state epidemiologist Dr. Paul Effler.

An additional 20 to 25 birds were collected Friday for testing, he said. The birds were caught in traps near the airport runway that have long been in use to prevent birds from interfering with aircraft. On Monday the Health Department began routine West Nile virus testing of birds trapped at Kahului Airport, as it has been doing at Honolulu International Airport since earlier in the year.

The department's vector control unit on Maui already periodically sprays the airport for mosquitoes. Friday night, in response to the West Nile threat, a two-man crew used truck-mounted and backpack-style foggers to treat the terminal and grounds with Permanone, an insecticide that kills adult mosquitoes.

The work was done after 11 p.m. when the airport had shut down for the night. Vector control worker James Kaimiola Jr., wearing a knit cap with a skull-and-crossbones pattern, said the chemical is effective at "knocking down" mosquitoes. Effler said the treatment would be continued last night, perhaps expanding beyond the usual airport spraying pattern, if weather permits.

Wackenhut security guard Mahinalani Kauhaa-Po, who works a night shift at Kahului Airport, said she usually doesn't like to apply mosquito repellent on her skin, but may reconsider after co-workers told her the disease could bring on brain swelling, coma and death.

Even still, she said she wasn't particularly worried, since most cases involve much milder symptoms. The U.S. Centers for Disease Control and Prevention reports that about 80 percent of the people infected with the virus do not get sick.

"We got over dengue fever, we'll get over this," Kauhaa-Po said.

Maui was ground zero for a small outbreak of dengue, another mosquito-borne disease, in late 2001 and early 2002. During a six-month period, there were 119 cases of dengue in Hawai'i, including 89 on Maui. There were no deaths.

Another Wackenhut guard, Alex Akuna, said he was alarmed to hear the West Nile virus may have spread to Maui, and he's going to take precautions, such as using mosquito repellent. But since he spends a good part of his graveyard shift patrolling in his car, he believes his chances of being bitten by mosquitoes are reduced.

West Nile virus caused 9,862 cases and 264 deaths last year in the United States,

Effler said West Nile virus in Hawai'i could also have serious consequences for endangered bird species and on the state's reputation as a safe tropical destination. He said that as an island, Hawai'i is the only state that could hope for eradication.

"We do not need to panic, but whether or not it is here, there is a need to take action because it looks like it's on the Mainland to stay," Effler said.

An outbreak of the West Nile virus probably would not have the same effect on tourism as the recent SARS scare because the disease is not as deadly and it is already prevalent on the Mainland, Effler said.

Maui visitors Mike and Linda Wilson of Alexandria, Ky., said they were not concerned about West Nile, and news of its possible spread here wouldn't have affected their plans to vacation in Hawai'i. "There are probably worse things going around than that," Mike Wilson said.

The virus also wasn't a concern for visitors David and Teresa Rydingsward of Suffield, Conn., because the virus has been in the eastern United States since 1999.

"Once they start spraying for it and as long as it's just one bird, they'll be able to keep it under control," David Rydingsward said.

In anticipation of a possible outbreak, the Health Department established dead-bird collection sites on the four major islands that have received "a substantial number" of carcasses, Effler said, but not enough to suggest an alarming increase in bird deaths.

He said the collection data is valuable because it will allow officials to quickly detect unusual trends in bird deaths that could indicate a wider spread of the disease.

On the Mainland, the West Nile virus had been particularly deadly for horses, and Maui's sizeable population of ranchers and equestrians are keeping close watch on developments.

Kula veterinarian Alan Kaufman said he has gotten a few calls from concerned horse owners, but there's no panic.

"Until the diagnosis is confirmed, I am not going to give encouragement to my clients that they rush right out and vaccinate their animals ... ," Kaufman said. "Even if it is here, the vaccine is readily available."

Horse owners should be no more concerned about the disease than they were a year ago, he said. They should worry more about vaccinating their horses against tetanus and other diseases that are a more serious threat, Kaufman said.