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Topics > Healthy Outlook > West Nile Virus

West Nile Virus

Published by Contra Costa Times
Posted on Wed, Apr. 06, 2005

By Francie Wise, BSN, MPH

THE PERIODS OF warm weather we've enjoyed in recent weeks were a welcome sign of spring arriving early, but arriving alongside is the threat of West Nile Virus.

As you may know, West Nile Virus (WNV) is a viral infection transmitted by a mosquito bite to humans, birds and horses. While only one in 150 people infected will get very sick, that sickness can cause paralysis, meningitis and encephalitis, which is a sometimes deadly swelling of the brain.

Even if you survive a severe case of the disease, it will take months to recover and it can damage your nervous system permanently.

Warmer weather and standing pools of water help mosquitoes breed, so the spring rains followed by sunshine create ideal conditions - and a greater probability of getting infected with WNV.

One of the first signs of the WNV season is dead birds found to be infected. We ask people to call 1-877-WNV-BIRD (1-877-968-2473) when they find a dead bird so it can be tested. Dead, infected birds have already been found this year in a dozen counties in California, including Contra Costa. That means in much of the state, it is already WNV season.

Twenty-seven people in California died of West Nile Virus-related illness in 2004, yet studies showed that many people on the West Coast still don't wear mosquito repellent with DEET when they go outside during mosquito season.

There is no vaccine against WNV and no test for people who are well. Since most people don't get symptoms, many cases go undiagnosed.

People over 50, those who have compromised immune systems and people who spend a lot time outdoors are all at higher risk for serious illness due to WNV.

The primary symptoms of WNV are fever, head and body aches, nausea and vomiting, swollen lymph nodes (tender lumps under the skin on the neck, underarms, inner elbow or groin) and/or skin rash.

In its more serious stage, symptoms include stiff neck, disorientation, paralysis, muscle weakness, tremors, convulsions or a coma.

West Nile Virus has been making its way westward across the United States over the past two years, first arriving in California last year.

We have yet to have a confirmed human case in Contra Costa, but the presence of the virus in two dead birds found recently in different parts of our county shows us that the disease is here again this year.

What can you do to avoid getting WNV infection?

  • Dump or drain standing pools of water, especially in the spring and summer
  • Put enough chlorine or other mosquito insecticide in ponds, pools and spas
  • Wear long sleeves and long pants, and mosquito repellent containing DEET, when outdoors or if mosquitoes are present
  • Repair or install screens on doors and windows to keep mosquitoes outside of your house
  • Call your health provider immediately if you have the symptoms described above.

Organizations wishing to receive educational materials about WNV - especially those who deal with the homeless, whose exposure is considerable - can e-mail requests to Contra Costa Health Services at or call 925-313-6744.

Members of the public seeking more information about WNV can find it online at or call Contra Costa Health Services' WNV hotline at 1-888-959-9911 or 211.

Francie Wise is director of communicable disease programs and public health nursing for Contra Costa Health Services.

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