Swarms of mosquitoes could raise West Nile risk

Flathead County health officials say swollen rivers and lakes may trigger a torrent of mosquitoes, raising the risk of West Nile virus.

"Three weeks from now, we could be looking at a lot of mosquitoes," Joe Russell, county health officer, said.

As water rises, rafts of mosquito eggs began to float, stimulating eggs to hatch. Areas of standing water nurture large populations of mosquitoes.

The threat to public health from West Nile virus prompted Russell to initiate discussions with county commissioners about forming a countywide mosquito district under streamlined procedures.

Legislation sponsored by Rep. Bernie Olson, R-Lakeside, now allows counties to initiate mosquito districts by a resolution or a petition.

Russell said the county attorney's office is drafting a resolution to start the process. Commissioners have asked for a proposed plan from the health department for operating the district.

"We're still very much in the preliminary phase of discussions," he said.

The process includes a public hearing for citizens to express their views on forming a tax

district to pay for mosquito control. It requires notification of all nonresident property owners by mail.

Russell said he envisions a countywide district with a minimal tax.

"This is not a big revenue generator," he said.

According to Russell, his home resides within an existing control district. He pays just $2.63 annually for the county service.

Russell said a valleywide mosquito abatement program offers the most public protection and makes the most sense from the perspective of coverage.

"We've got to get a mosquito district moving," Russell said. "Everyone's affected."

He said a huge hatch could occur even as soon as in two weeks.

With a rising tide of mosquitoes, health officials anticipate a greater threat of the spread of the mosquito-borne, West Nile virus.

Similar to dengue and yellow fever, the virus caused illness in 228 Montanans in 2003. Four people died as a result of severe encephalitis or Meningitis, swelling of the brain or spinal cord.

After dire predictions for 2004, only six people tested positive for virus exposure. None of those died.

After spreading across Eastern Montana, the virus has yet to infect people in Western Montana. However, horses have contracted the disease in Lake County, leading to fears of human cases soon.

"Our focus is on larvae," Russell said. "If we can kill larvae, we don't have adults (mosquitoes)."

To combat mosquitoes, county contractor Jed Fisher has expanded larvicide efforts as much as possible with the time he has available.

However, Fisher has informed county officials he wants to terminate his part-time, off-duty mosquito control work. As a full-time county employee, he said he can't put enough time into mosquito control.

Russell said it's most likely too late for a county-wide mosquito district to have much impact on spring preventive measures like larvicide.

A threat of West Nile virus may require spraying for adult mosquitoes. In previous years, aerial spraying plans triggered public protests from organic farmers and people with chemical sensitivities.

"When you build your decision tree, the threat of West Nile virus must be imminent," Russell said.

The county faces a shortage of people like Fisher with the training and licensing to perform ultra low volume, truck-mounted spraying.

If faced with a public health emergency from West Nile virus, Russell said the county could consider spraying to kill adult mosquitoes from a helicopter.

According to statistics, adults over 50 face the greatest risk of serious illness from West Nile virus. About 1 in 150 infections results in severe neurological disease.

About 80 percent of people infected notice no symptoms and subsequently develop immunity to the virus.

The primary symptom is a fever which begins suddenly. The virus may also produce mild, flu-like symptoms such as nausea, vomiting, eye pain, headache, muscle pain, rash or swollen lymph nodes.

About one in 1,000 cases proves fatal.

Reporter Candace Chase may be reached at 758-4436 or by e-mail at cchase@dailyinterlake.com.