West Nile caution advised

As people are outdoors for Fourth of July festivities this weekend, they're advised to guard against mosquito bites that can make them seriously ill.

Last month, two dead birds discovered in west Ceres were reported to the state's West Nile virus hot line and they tested positive for the mosquito-borne illness, Stanislaus County officials said.

The positive tests are a sign the potentially deadly virus is active as residents prepare for the holiday weekend. The illness attacks the central nervous system. It proved fatal for an 85-year-old Modesto woman last year and caused serious illness in a 7-year-old Modesto girl.

"If people are out enjoying the fireworks this weekend, we hope they will consider using insect repellent and taking other precautions to protect themselves from mosquitoes that may be infected," said Jerry Davis, general manager of the Turlock Mosquito Abatement District.

As of this week, the virus has been detected in a dozen California counties, including Stanislaus and Merced, according to the state Department of Public Health.

The virus surfaces every year in the Northern San Joaquin Valley. Positive tests on animals or mosquitoes often are followed by people exhibiting symptoms of the virus. Thirteen people are known to have been stricken last year in Stanislaus County. Merced County reported its first fatality in 2009.

After the two dead crows tested positive, the Turlock abatement district set traps and sprayed insecticide in the residential areas near Morgan Road in Ceres.

Subsequent tests on mosquitoes collected from that area came back negative, Davis said.

The district isolated 10 neglected swimming pools within a half-mile of the dead crows and found mosquitoes breeding in nearby irrigation gates. But the crows could have been infected elsewhere, officials said.

"The virus can strike at any time," said Dan Davis, a retired fire chief and emergency operations manager who serves on Stanislaus County's West Nile Virus Task Force. "It is extremely important that as parents, grandparents and caregivers, we remember to apply insect repellent to our loved ones before they go outside."

Mosquito abatement officials focused attention this spring on neglected pools and other breeding sites in residential areas.

Most of the property owners cleaned their pools after a visit by mosquito abatement inspectors. But some do not continue pool maintenance, so it's important for people to keep reporting problems to the mosquito abatement districts, Jerry Davis said.

Horses are also susceptible to West Nile illness and can be protected with annual vaccinations. Stanislaus County had two equine cases last year, resulting in one death. Neither horse had been vaccinated.

Bee staff writer Ken Carlson can be reached at kcarlson@modbee.com or 578-2321.