By TONY Di DOMIZIO
Journal Register News Service

When it takes hold, there are no symptoms.

It's been around for more than 1,000 years. It is supposedly one of the causes of the early death of Alexander the Great, or so says the Centers for Disease Control (CDC).

The American robin and crow are its common carriers. There is no vaccine for it — and the season for the West Nile virus is heating up.

According to Harriet Morton of the Montgomery County Department of Health, the West Nile virus season began April 1 and runs through October.

The main thing one can do to prevent the spread of the virus is to get rid of any standing water.

"Check around the house and make sure any windows or screens are repaired so they can't get in that way," Morton said. "If you see anything that can contain water, like old tires, cans, bottles or buckets, get rid of it. Even a minute amount of water can breed mosquitoes."

If the children are done using the kiddie pool for the time being, empty the water so mosquitoes won't be attracted to the water. Empty plant containers, flower pots, bird baths and pool covers.

"Make sure gutters are drained properly. If water can stagnate, get that out of there," Morton said.

Avoiding mosquito bites is one surefire way to avoid infection.

Remain indoors at dawn or dusk and wear light-colored clothing that covers the arms and legs. Mosquitoes are drawn to the color blue.

Stick with light shades of khaki, beige and olive. Dark shades absorb more light and produce more heat, and mosquitoes are attracted to heat, especially body heat.

Using insect repellents on the skin and clothing can be effective. There are products that carry the chemical DEET and picaradin, which aid in fending off mosquitoes. Oil of lemon eucalyptus for the skin and permethrin for clothes also works as a repellent.

There is no vaccine for West Nile virus for humans. The CDC recommends if one becomes infected, treatment is supportive. Analgesics are given for the pain of neurologic diseases and rehydration for nausea, vomiting, or diarrhea.

The main route of human infection of West Nile is through the bite of an infected mosquito. Mosquitoes bite and infect birds, which are hosts, and develop enough viral levels to transmit the infection to other biting mosquitoes. Those mosquitoes then go on to infect other birds and humans.

The virus at first shows no symptoms in an infected human. Then, some two to eight days later, fever, headache, chills, excessive sweating, swollen lymph nodes, weakness and pain in the joints begin to set in.

The symptoms mock that of the common cold, and sometimes there is a rash. Nausea, vomiting and loss of appetite are other telltale signs.

West Nile can then reach a third and fatal stage of neuroinvasive disease where the brain becomes inflamed, known as West Nile encephalitis, and the membrane around the brain and spinal cord become inflamed, known as West Nile meningitis. WIth neuroinvasive diseases, one becomes less conscious and reflexes are diminished.

The virus can be spread by human-to-human transmission as well, such as through blood transfusion, organ transplant, intrauterine exposure and breast feeding, according to the CDC.

Montgomery County residents can register for the Montgomery County Community Alert System. The Roam Secure Alert Network will immediately contact a user through e-mail, cell phone, pager or PDA during a major crisis or emergency with alerts, notifications and updates on everything from weather and traffic to West Nile Virus sprays in a municipality and school district.

Log onto https://montco.alertpa.org and click "New User" and create a profile to register.

"Any press release we put out, they would get it," Morton said. "We're adding West Nile notifications to it, so they will get information about a spray we will do or positive mosquito tests."

More than 3,000 have signed up for the network.

"They're trying to get the whole region to sign up to get notifications," she said. "In addition to health alerts, you can get weather, traffic, anything that is going on in the township or borough. You get information where you work and where you live."

In 2008, 14 human cases were reported and one died in Pennsylvania from West Nile Virus, according to the county health department.

In Montgomery County, there were three human cases in 2008.