An insect that measures less than a few inches and can typically be found in nearly every backyard in State College has been causing concern throughout the state this summer.

The mosquito, which can carry the West Nile virus, has become a danger to the East Coast of the United States in recent months. The virus, once strictly an Eastern Hemisphere problem, is spreading though the nation and threatens to touch the West Coast.

The national death toll from the West Nile virus has risen to 20 as the disease continues to spread, according to the Centers for Disease Control. The virus has infected 425 people in the nation.

In Centre County, West Nile has been found in seven dead birds and one mosquito sample, according to the Department of Environmental Protection (DEP).

Of the reported cases that tested positive, five of the infected birds were found in the State College Borough. The remaining two infected birds were found in Boggs Township and in the Port Matilda Borough. The mosquito was found in Boggs Township.

There have been no deaths related to the West Nile virus in Pennsylvania. There were three reported cases of humans contracting the virus in Pennsylvania last year, but all victims recovered fully.

"We have a pretty aggressive program," said Ron Ruman, information specialist for the DEP. "In April we begin by monitoring mosquito larva populations and when we find some that are infected we immediately begin destroying them. Later, when they hatch, we start monitoring the adult populations."

Surveillance for Centre County looks at the breeding sites for mosquitoes. Traps are used to collect specimens to send away for testing, said Terry Maddox, West Nile coordinator for Centre County.

"A fan is used to draw them [mosquitoes] into a mesh net," Maddox said. "We use carbon dioxide to draw the mosquitoes in. Then we place the samples on dry ice and send them away for testing."

Though most of the infected birds and mammals found in Centre County were located in the State College area, this does not mean the region has been harder hit than surrounding areas.

"In the public mind this shouldn't mean that it's a bad problem there," Ruman said. "We are just asking people to take the proper precautions."

People are advised to wear a insect repellant containing DEET, to wear long sleeves and long pants whenever possible and to be especially careful during the peak risk hours of dawn and dusk, Ruman said.

Additionally, people are urged to eliminate standing water on their property.

"It doesn't have to be a lot," Ruman said. "It could be a small amount found in a bucket or a bird bath. One of the worst places is in old tires."

There is no known cure for the virus.

The symptoms are similar to the flu. Some common symptoms include swollen glands and a mild fever, Ruman said.

Those who feel they might have been exposed to the virus should contact a physician immediately. The virus usually affects the elderly, the very young and those with weakened immune systems, Ruman said. The virus occasionally causes encephalitis, an inflammation of the brain that can be fatal.

There is no specific treatment for the virus, but most people recover completely from it.

"Most people who acquire the virus never know," Ruman said. "They would think they have the flu and in a few days they will completely recover."

Fewer than one of 150 people infected with West Nile ever know they had the virus, Ruman said.

There is no vaccine to prevent the transmission of the virus.

"There is some testing [to create a vaccine], but for now there is no way to prevent the transmission of the virus," Ruman said.

There is no evidence that the virus can be spread from human-to-human contact or from contact with an infected animal.

The virus is spread when an infected mosquito bites an bird or mammal. The infected birds and mammals can then spread the virus when uninfected mosquitoes bite them.

The U.S. Department of Health and Human Services (HHS) announced Wednesday that additional funds were being awarded to help states control the virus. The HHS is awarding an additional $4 million through the CDC to states hit hardest by the West Nile virus.

The $4 million is supplementing the $10 million in West Nile aid that was already made available to states two weeks ago by the CDC a few weeks ago.

Pennsylvania has provided the DEP with $11 million in funding for West Nile programs. The DEP launched its West Nile prevention program in 2000.

Yesterday the DEP announced plans to begin spraying to control adult populations in Dauphin and Lancaster counties. The counties and the DEP samplings have shown unusually large numbers of mosquitoes that can potentially carry the West Nile virus, according to the DEP.

Adult mosquito control is an unusual step to take for controlling West Nile, according to the DEP, but they "feel it is better to be out front dealing with the large mosquito population" the counties face this summer.

The spray has no impact on human health and breaks down quickly, according to the DEP. Spraying will be directed onto vegetation and wooded areas.

Adult mosquito control is only used in limited situations where larval controls are unable to prevent large numbers of adult mosquitoes, according to the DEP.

The virus was first reported in the U.S. when it was found in New York City in 1999.

Some experts have speculated that the cause for the rise of West Nile in the United States has to do with global warming. However, Liwang Cui, associate professor of entomology at Penn State, disagrees.

"Probably this is not accurate," Cui said. "It was probably transported [to the U.S.] from an infected bird."

Studies are being conducted to study the biological makeup of the West Nile virus found in the United States. Later the findings will be compared to the makeup of the viruses that are found in other countries. This will help scientists to discover the origin of the virus present in the United States, Cui said.

West Nile was first discovered in 1937 in the West Nile District of Uganda, Cui said. The virus became recognized as a cause of severe human meningoencephalitis --inflammation of the spinal cord and brain -- during an outbreak in Israel in 1957.