By Michael E. Ruane

Washington Post Staff Writer

Sunday, April 15, 2001; Page C01

They searched for it in old military bunkers in Maryland, in abandoned buildings in Bridgeport, Conn., and in dank corners near where it was rampant last year in New York City.

But this winter, unlike the winter before, the potentially deadly microbe that is officially called NY99, and is better known as West Nile virus, could not be found.

Was the strange, mosquito-borne malady that last year killed wildlife in 12 states from New Hampshire to North Carolina gone? Probably not, say scientists, who have studied the virus since its arrival two years ago.

In fact, most believe that the virus will be back, spreading -- if last year is a guide -- well into the South, and perhaps beyond the borders of the United States.

"It's clear that the virus hasn't gone away," said Stephen Ostroff, of the Centers for Disease Control and Prevention, the federal West Nile Virus coordinator. "It was just in too many different areas" last year.

But scientists may shift their strategy for containing the spread. Pesticide spraying, conducted in parts of the Washington region last year, will probably be more limited. And the chicken sentinels, set out to signal the disease's approach, will probably be abandoned.

The old-fashioned fly swatter, in some places, and a new vaccine next year could instead help fight the disease's spread.

Locally, experts said, the virus could easily reappear more strongly this year in areas that it first reached last year, especially in mid-Atlantic urban areas.

"The only thing we can go on is what happened last year," said CDC biologist Nicholas Komar. "It spread several hundred miles in one season. In all directions.

"If it does that again this year, it will move into places with big cities like maybe Toronto, Ontario, or Atlanta, Georgia," he said in a telephone interview Thursday.

"And some of the population centers in the current distribution are at risk for major outbreaks, like Baltimore and Washington and Philadelphia," he said. "I'm not saying that outbreaks will occur. But these are places at risk for an outbreak."

In response, the federal government has allocated $25 million this year to combat the virus, a substantial increase over the $9 million in federal money that was available last year, the CDC's Ostroff said.

Maryland officials held a nuts-and-bolts virus planning meeting last week in Annapolis and announced that the new West Nile hot line number, not yet activated, will be 1-866-866-CROW.

Maryland has begun routine application of larvicides in some areas, designed to kill mosquito larvae before they become adults.

Virginia has upgraded its laboratory facilities in Richmond to streamline analysis of tissue from wildlife that may have been infected, a state health official said.

West Nile virus in humans is not serious in most cases, but in the elderly it can causedeadly encephalitis, or swelling of the brain.

Since its first appearance in the United States in summer 1999, the virus has made 83 people seriously ill and killed nine, mostly in the New York City region. Its greatest toll has been in the wild, however, where during two summers it has killed thousands of crows and other birds, along with numerous horses.

The virus is transmitted when a mosquito bites an infected person, bird or other animal, picks up the microbe and then bites someone or something else.

Study of West Nile has been complicated because only certain mosquitoes are efficient carriers. Many creatures don't die or even get sick from it, though they may act as virus "reservoirs" or storage tanks. And it has high mobility, because most of its victims have been birds.

Scientists are not sure how West Nile got here from its native territory in Europe, Africa and the Middle East, the CDC says.

There have been no human cases in the Washington area. But last year, 50 infected birds were found in Maryland, seven in Virginia and three in the District. Experts believe hundreds of others went undetected.

Only one infected bird had been found locally the year before, in Baltimore.

This year, experts said, one of the main concerns will be how far the virus spreads after its dramatic geographic expansion last year, well beyond the New York City area, where it emerged the year before.

The CDC, mindful of the recent jump of the more deadly Japanese encephalitis from Asia to Australia, suggested this month that West Nile surveillance start in every state in the continental United States and as far away as South America.

One federal wildlife expert is capturing birds in Florida to see whether West Nile has spread to species there, and another will travel to Puerto Rico later this month to assist surveillance there.

State and federal experts said they anticipate less pesticide spraying this year for adult mosquitoes, a practice that created intense controversy in some areas last year.

Although some officials believe spraying limited the virus's impact on people last year, experts in Connecticut point out that they did very little spraying, despite thousands of bird deaths, and had only one human case reported.

Furthermore, when they took blood samples from 730 people in Stamford in October, searching for unreported infections, they found none.

"We only sprayed on three occasions," said state epidemiologist Theodore G. Andreadis. "As it turns out, we probably did the right thing."

The CDC's new recommendations also play down the role of pesticides, suggesting that spraying seriously be considered only when the virus is confirmed in a person or a horse, or in cases of "moderate" virus activity in birds and/or humans.

"Simply seeing one [virus] positive bird probably doesn't represent a very high risk of transmission to humans in that area," said Ostroff, of the CDC. "So there shouldn't be as strong a likelihood that the response would be to go out and spray."

Another change in the fight this year is the scrapping of sentinel chickens. Numerous flocks were established last year, and their blood was tested for virus all summer. But they proved ineffective, the CDC said, and are not expected to be used this year.

A new innovation, though, is being tried in Bergen County, N.J., where fly swatters are being made available to the public.

Meanwhile, the search for a vaccine is progressing.

Thomas P. Monath, vice president of Acambis Inc., a Massachusetts firm that last year got a $3 million federal grant to develop a vaccine, said Friday that tests are going well.

A candidate for a human vaccine is now being tested in mice, he said, and could be ready for human testing by late next year.

He said the company's vaccine-making technique is the same one used to make a similar vaccine that has just been tested successfully for Japanese encephalitis, a close kin to West Nile.

"If it works for Japanese encephalitis," Monath said, "it'll work for West Nile."

© 2001 The Washington Post Company

-- Anonymous, April 15, 2001

Answers

I had the vet here this week.....and told him I was worried sick for the "boys"...he told me there was nothing yet for them.....and they think it'll hit ohio Valley by next year.

-- Anonymous, April 15, 2001

Repellents would be the only possible precaution, SAR, as I'm sure you've alrady figured out, and they'd have to be natural, of course. Realgoods.com has some coils and also some electronic mosquito repellents. You might want to have a look at their site. (Those "mosquito repellent" plants don't work, according to Consumer Reports.)

-- Anonymous, April 15, 2001

SAR, we use to put Skin So Soft (from Avon) mixed in with water for my horse, to help keep the mosquitoes off. The electronic mosquito repellents, that Old Git spoke of...really work. I've had two of them for several years now. I don't know the name of them. On the box it say stop mosquitoes and there is a picture of a mosquito on the dial that controls the frequency output. They are about the size of a small match box.

-- Anonymous, April 15, 2001

Is it this one, Maggie?

(found here)

-- Anonymous, April 15, 2001

OG, came back to this thread and you already found one, put up the picture AND the hot link to the site!

The one that has a picture of it... looks to be about the same size and has the chain with key ring on top but, the ones I have...has a frequency dial on the front of the case, with numbers from 1 to 10. It may be just as good as the ones I have.

-- Anonymous, April 15, 2001

It says:

Solar Mosquito Guard

We've received countless raves from satisfied Solar Mosquito Guard owners from Hawaii to the Amazon Basin, from Alaska to Louisiana all with the same theme: "These amazing things really work, we're mosquito free, while our friends are swatting away." The principle is they put out a high-frequency audible wave that actually repels most species of mosquitoes. Funny part is there is no scientific evidence that mosquitoes can even hear, yet they really seem to work! There is an on/off switch so you don't have to activate until the mosquitoes arrive. The battery will recharge in three hours of sunlight. Hong Kong. $8.95, 3 for $6.95 each.

Hmm. Made in China. If there's no US-made alternative, don't NOT buy this because it's made in China, SAR. Now if it were a lighthouse lawn ornament, well, that would be a lot different.

-- Anonymous, April 15, 2001