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For Immediate Release:
July 24, 2008
For more information contact:
Public Health Communications
(213) 240-8144

Public Health Officials Report First West Nile Virus Cases in Los Angeles County
Residents Urged To Remove Standing Water Near Homes and To Wear Insect Repellant to Protect Themselves from Mosquito Bites

LOS ANGELES - The Los Angeles County Department of Public Health has confirmed four human West Nile Virus (WNV) infections in Los Angeles County, the first cases of the 2008 season. Three male adults and one male child were infected. All cases were symptomatic except one male adult case. The symptomatic individuals were hospitalized with meningitis in July and are recovering. The asymptomatic individual was a blood donor whose infection was detected as part of routine WNV screening tests conducted to ensure safety of the blood supply. The individuals live in the eastern and southeastern sections of the county.

Last week, the California Department of Public Health and the Greater Los Angeles Vector Control District detected WNV in nine new dead birds and eleven mosquito pools in Los Angeles County. The infected birds were found in the eastern region of Los Angeles County near the San Gabriel Valley area; WNV-infected mosquito pools, however, were found mainly in the San Fernando Valley.

"West Nile Virus can appear anywhere in Los Angeles County or around the state. Our warm weather encourages mosquito breeding, but the weather is also an invitation for individuals to spend more time outdoors. When they do, residents should take precautions to avoid mosquitoes bites," said Jonathan Fielding, M.D., M.P.H., Director of Public Health and County Health Officer. "People should make sure pools of stagnant water are removed from around their homes and to wear insect repellant containing DEET or picaridin, when outdoors in mosquito prone areas, especially close to dawn and dusk."

Eleven human symptomatic cases of WNV disease have been identified in seven California counties this year so far. In addition to the Los Angeles cases: Fresno (1), Orange (2), San Diego (1), San Joaquin (1), Tulare (1), and Stanislaus (2). In 2007, there were 43 cases and 5 deaths in Los Angeles County due to WNV. Twenty-eight California counties, largely in the central and southern parts of the state, have documented some form of WNV activity this season.

West Nile Virus is spread to humans from the bite of an infected mosquito; mosquitoes can become infected by biting a bird that carries the virus. Most mosquitoes do not carry the virus and most people bitten by a mosquito have not been exposed to the virus. The virus is not spread by person-to-person contact or directly from birds to humans. The virus is a seasonal epidemic that flares up in the summer and sometimes continues into the fall. West Nile Virus is endemic to the state of California.

Symptoms Approximately 80% of people infected with WNV do not exhibit symptoms. Some 20% or 1 in 5 infected persons may develop West Nile Fever, with symptoms such as high fever, headache, body aches, nausea, vomiting, and sometimes a skin rash on the chest, stomach and back. Symptoms can last anywhere from a few days to several weeks. Other WNV symptoms include stiff neck, stupor, disorientation, coma, muscle weakness, and paralysis.

The elderly and immune-compromised individuals, i.e., those with HIV/AIDS, diabetes, or hypertension, are at greatest risk for serious illness.

Prevention People can decrease their risk of infection by following these recommendations:

  • Check for and remove all sources of standing water.
  • Change the water in wading pools, birdbaths and pet bowls twice weekly.
  • Place mosquito-eating fish in ornamental ponds and water gardens.
  • Make sure that doors and windows have tight fitting screens.
  • Repair or replace screens that have tears or holes.
  • Avoid mosquito-infested areas at dawn and dusk.
  • Where it is necessary to be outdoors during these times, wear long pants, long-sleeved shirts and other protective clothing.
  • Use repellants containing DEET, picaridin, or oil of lemon eucalyptus, according to label instructions.
  • California's WNV Web site - www.westnile.ca.gov - has the latest information on WNV activity in the state. In order to help identify WNV activity, Californians are encouraged to report all dead birds and dead tree squirrels on the Web site or call toll-free 1-877-WNV-BIRD (968-2473). Local information is also available at www.publichealth.lacounty.gov.

    Where to call with questions about mosquitoes: Greater Los Angeles County Vector Control District: (562) 944-9656 Los Angeles County West Vector Control District: (310) 915-7370 San Gabriel Valley Mosquito and Vector Control District (626) 814-9466 Antelope Valley Mosquito and Vector Control District: 661) 942-2917 Compton Creek Mosquito Abatement District: (310) 639-7375 Pasadena Public Health Department: (626) 744-6004 City of Long Beach Vector Control Program: (562) 570-4132

    The Department of Public Health is committed to protecting and improving the health of the nearly 10 million residents of Los Angeles County. Through a variety of programs, community partnerships and services, Public Health oversees environmental health, disease control, and community and family health. Public Health comprises more than 4,000 employees and an annual budget exceeding $750 million. To learn more about Public Health and the work we do, please visit http://www.publichealth.lacounty.gov.


    Related Information Site(s): Department of Public Health | California West Nile Virus Web site