Texas Man in L.A. County Tested for West Nile Virus

A second probable case of West Nile virus has surfaced in Los Angeles County, this time in a middle-aged Texas man who authorities believe contracted the infection from a mosquito bite in his home state.

The Houston-area man became ill with encephalitis while visiting relatives in the county in late August, and has been hospitalized here for about two weeks, said Dr. Jonathan Fielding, the county’s public health director. The man remembers being bitten by mosquitoes in Texas.

The probable case comes after Friday’s announcement that a young woman who lives in the southwestern part of the county very likely contracted viral meningitis from a West Nile virus. If her diagnosis is confirmed, she would represent the first human case of West Nile acquired west of the Rocky Mountains.

Lab tests for West Nile were inconclusive for a third person, a young Las Vegas woman hospitalized in Los Angeles for encephalitis, an inflammation of the brain that can be caused by West Nile. The woman had recently traveled to the Houston area, although health officials do not know if her trip fell within the West Nile incubation period of three to 14 days.

The Houston man and Las Vegas woman are recovering, Fielding said. The third person has recovered.

None of the victims were identified, to protect their privacy.

Fielding said additional tests are required in all three cases before a final diagnosis can be made. The tests will look for the presence of antibodies to West Nile and rule out other types of infection.

Tests have been negative in three other people, Fielding said.

The two cases disclosed Monday, if confirmed, would not be considered California infections under federal guidelines because they weren’t acquired here. In recent days, other Western states have reported at least four other West Nile cases that were acquired east of the Rockies.

So far this year, 985 people have been diagnosed with West Nile virus in 30 states and the District of Columbia. Forty-three people have died. On Monday, New Jersey became the latest state to report its first infections to the U.S. Centers for Disease Control and Prevention. Two people were diagnosed.

West Nile is harbored in birds and transmitted to humans by mosquitoes. About one infected person in five shows mild symptoms, which include fever, headache and nausea. About one in 150 require hospitalization.

Generally, health officials first detect the presence of West Nile in a region by testing mosquitoes, dead birds, chickens and horses. But as of Monday, all such tests in California have been negative.

Los Angeles County began spraying mosquito-killing chemicals more than a year ago, knowing that the West Nile virus would eventually reach the area.

Fielding said people can minimize their risk by avoiding mosquito-infested areas at dawn and dusk; wearing long-sleeved shirts and long pants outdoors; using insect-repellent products with no more than 35% DEET for adults and 10% for children; and ensuring that windows have intact screens.

Officials also advised against allowing pools of water to stagnate. They recommended cleaning and chlorinating swimming pools and draining water from pool covers.

Californians who see birds that have been dead for less than 24 hours are asked to report them to health authorities at (877) 968-2473. Authorities will test for the presence of the virus. Los Angeles County has also set up a general information hotline: (800) 975-4448.