Sept. 3, 2004


Communicable Disease: West Nile Virus

Principal Investigator: David McNutt, MD, MPH, Health Officer

Date: Sept. 3, 2004

Press Release #: 2004WNV1


West Nile Virus (WNV) has been detected in 3 birds from Santa Cruz County, a swallow and 2 Western scrub jays.


      The positive birds were found in the Rio Del Mar and Aptos areas and the city of Watsonville.

      Detection of the virus in birds means that we may see human cases in the next few weeks.



      Mosquito and Vector Control technicians have been sent to all 3 sites to target mosquito breeding sources in the area.

      Public Health is coordinating activities with the California State Department of Health, the Mosquito and Vector Control Program in South County and the Environmental Health Dept.

      A Public Health Alert was sent to health care providers in the county with specific information on signs and symptoms of West Nile Virus on May 25, 2004.

      A Public Health education campaign was started at the beginning of the mosquito season, including advertisements in local papers and movie theaters, TV reports, and outreach to senior centers and long-term care facilities.



      There is no evidence of horses and birds transmitting WNV directly to humans.

      WNV is transmitted to humans and animals by mosquitoes and is not transmitted by casual person-to-person contact. Rarely, it has been transmitted via blood transfusions or organ transplants.

      New blood bank procedures now screen for WNV.

      Horses can become ill from WNV but cats and dogs seem to be resistant to WNV.

      There is a vaccine available for horses that has proven over time to be safe and effective. There is no vaccine as yet for humans.



      The best way to protect yourself from WNV is to prevent exposure to mosquitoes.

      Drain all standing water at least once a week to prevent mosquitoes from breeding. Be sure to check rain gutters, plants, buckets, pool and spa covers, bird baths and any other items in your yard that may contain standing water.

      Dress in long sleeves and long pants when outdoors.

      Avoid going outside at dusk and dawn when mosquitoes are most active.



      Use mosquito repellent that contains DEET on exposed skin when you go outside. You may also spray clothing with repellents that contain DEET or permethrin. Do not spray repellent on skin under clothing. Do not use permethrin directly on skin. Repellents are safe and effective when used according to the directions on the package. Be sure to read and follow the manufacturers DIRECTION FOR USE, especially when using on children.

      Make sure window screens are in good repair to prevent mosquitoes from entering the home.




For more information on West Nile Virus, visit or


Health Alert: conveys the highest level of importance; warrants immediate action or attention.


Health Advisory: provides important information for a specific incident or situation; may not require immediate action.


Health Update: provides updated information regarding an incident or situation; unlikely to require immediate action.