|CA Dept. of Public Health||UC Davis Arbovirus Research and Training||Mosquito and Vector Control Assoc. of CA|
Case Counts by County
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CALIFORNIA DEPARTMENT OF PUBLIC HEALTH ANNOUNCES SECOND DEATH FROM WEST NILE VIRUS IN 2007Jul 24, 2007
WNV activity has been detected in 36 of California's 58 counties. To date in 2007, 36 individuals, including the two who died in Kern County, have become ill after exposure to WNV.
Kern County accounts for 28 of the reported WNV illnesses. Fresno, Glenn, Imperial, Mendocino, Merced and San Joaquin counties have each reported one illness, while Stanislaus County has reported two. WNV also has been detected in 355 dead birds, 221 mosquito samples, four horses, 22 chickens and five squirrels.
"The recent increase in West Nile virus-related illnesses follows an established pattern," Horton said. "As the temperature rises, so does the spread of West Nile virus from mosquitoes to people and animals."
In anticipation of warmer temperatures, mosquito control efforts have intensified throughout the Central Valley. Aerial spraying to control mosquitoes has been conducted in selected areas of San Joaquin County, and many counties have started ground-based "fogging." In addition, many local agencies are increasing their mosquito control efforts in underground storm drains and surveying backyards via helicopter for neglected swimming pools that can breed thousands of mosquitoes, an increasing problem due to the rise this year in home foreclosures.
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.
WNV is transmitted to humans and animals through a mosquito bite. Mosquitoes become infected when they feed on infected birds and tree squirrels.
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.
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).
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Compared to previous year and previous five-year average to date