Welcome to the State of California 


Date: 7/31/2007 

Number: PH07-16 

Contact: Suanne Buggy or Ken August (916)-440-7259 


Dr. Mark Horton, director of the California Department of Public Health (CDPH), today announced the third and fourth deaths in 2007 of Californians due to complications associated with West Nile virus (WNV). An elderly San Joaquin County man and an elderly Colusa County woman have both died of West Nile neuroinvasive disease. The two previous fatalities involved an elderly Kern County man and woman.

“The unfortunate deaths of these Californians remind us that we must take precautionary measures to protect ourselves against mosquito bites and West Nile virus, especially during the summer months,” said Horton.

WNV is transmitted to humans and animals through a mosquito bite. Mosquitoes become infected when they feed on infected birds.
WNV activity has been detected in 38 of California’s 58 counties. To date in 2007, 56 individuals from 13 counties, including the four who have died, have become ill after exposure to WNV.

Kern County accounts for 38 of the reported WNV illnesses. Other counties have reported the following numbers of illnesses: Butte, 2; Colusa, 1; Fresno, 3; Glenn, 1; Imperial, 1; Mendocino, 1; Merced, 1; Sacramento, 1; San Joaquin, 2; Shasta, 1; Sonoma, 1; Stanislaus, 3. WNV also has been detected in 423 dead birds, 317 mosquito samples, five horses, 30 chickens and five squirrels.

The most effective ways for individuals to prevent exposure to mosquito bites and WNV are:

  • Apply insect repellent containing DEET, picaradin or oil of lemon eucalyptus, according to label instructions.
  • Ensure doors and windows have tight-fitting screens. Repair or replace screens that have tears or holes.
  • Eliminate all sources of standing water that can support mosquito breeding.
  • Wear clothing that reduces the risk of skin exposure and avoid spending time outside at dusk and dawn when mosquitoes are most active.

Most individuals who are infected with WNV will not experience any illness. Individuals 50 years of age and older have a higher chance of getting sick and are more likely to develop serious symptoms when infected with WNV. Recent data also indicate that those with diabetes and/or hypertension are at greatest risk for serious illness.

California has one of the most comprehensive WNV surveillance and control systems in the United States. In recognition of the key role these systems play in controlling WNV, Governor Arnold Schwarzenegger included $3 million in the 2006-2007 budget to supplement existing mosquito control and abatement efforts in high-risk areas and "hot spots." These funds have been distributed to 61 local agencies.
In addition, CDPH uses surveillance and detection technology to track specific areas of WNV activity and alert local agencies so they may target their mosquito control activities.

For more information about WNV and to report dead birds and tree squirrels, visit www.westnile.ca.gov or call toll-free 1-877-WNV-BIRD (968-2473).

Last modified on: 6/2/2009 9:48 AM