WEST COVINA, Calif. (CNS) — A vector control official is reminding people to take precautions when outside this holiday weekend to protect against West Nile virus, the most common mosquito-borne disease that affects residents in Los Angeles County.

The San Gabriel Valley Mosquito & Vector Control District advises people to dump stagnant water ahead of any outdoor gatherings, toss unused containers that can hold stagnant water, and make sure to use mosquito repellent containing any one of the following CDC-recommended ingredients: Picaridin, DEET, oil of lemon eucalyptus (or PMD) or IR3535.

"Imagine celebrating this weekend and getting mosquito bites up and down your legs or arms," said District spokesman Levy Sun. "Staying bite-free means worrying less about mosquitoes and the diseases they can spread."

West Nile virus is spread to people through mosquito bites. Birds can become sick from West Nile, but do not spread the virus directly to people.

The District conducts mosquito trapping and dead bird testing to determine the risk and spread of West Nile virus. When necessary, treatments are made depending on west nile activity and the presence of mosquitoes carrying the virus.

As of Friday, the District has confirmed West Nile virus positive birds and mosquito samples in the following cities and communities:

— Covina: nine mosquito samples, four dead birds;

— South Pasadena: one dead bird;

— Unincorporated L.A. County (Vincent neighborhood): three mosquito samples; and

— West Covina: three mosquito samples.

According to the Los Angeles County Department of Public Health, one in five individuals infected with the West Nile virus, for which there is no cure, will exhibit symptoms that include fever, headache, body aches, nausea or skin rash. The symptoms can last for several days to months.

One in 150 people infected with the virus will require hospitalization. Severe symptoms include high fever, muscle weakness, neck stiffness, coma, paralysis and possibly death.

Those at greatest risk include seniors and individuals with compromised immune systems. People over 50 and those with chronic health problems are at higher risk of severe illness. While not all mosquitoes carry this virus, the type of mosquito that spreads this virus is found throughout Los Angeles County.

Mosquitoes in Southern California are generally more active from May to October.

"Mosquito control is a responsibility shared by all residents, businesses and property owners," Sun said. "Let's stay bite-free as we celebrate this holiday weekend."

For more information, or to report neglected swimming pools of stagnant water, visit www.SGVMosquito.org or call 626-814-9466.