Sacramento County's West Nile virus toll has continued its sharp climb, jumping by 31 percent in just four days, according to newly released data.
Local health officials said Tuesday that the county caseload increased from 36 to 47 between Friday and Tuesday. The 11 new cases in Sacramento County represent about a third of all cases reported in California since Friday.
"It looks like this year Sacramento is the epicenter for West Nile virus in Northern California, at least for now," said Dr. Glennah Trochet, Sacramento County health officer. "It underscores the need for all of us to continue to protect ourselves - using insecticides and not providing breeding grounds for mosquitoes."
Sacramento County continues to lead the state in human West Nile activity. The state reported a total of 208 human cases Tuesday, up from 174 Friday. Five people have died this year of complications from West Nile virus. Among them are an elderly Butte County man whose death was reported by health officials Monday and an 86-year-old San Joaquin County man whose death was reported last week.
Also on Tuesday, the Sacramento-Yolo Mosquito and Vector Control District again scrapped plans to continue aerial spraying over the southern part of Sacramento County. High winds have thwarted the air assault since late last week.
The district is doing the treatments to stop the spread of West Nile, which is passed by infected mosquitoes.
Early last week, three nights of carpeting just over 50,000 acres of northern Sacramento County with a fine mist of pesticide drastically reduced mosquitoes, according to vector control officials. Traps in the north area showed mosquito kill rates of between 40 percent and 80 percent following the spraying.
Vector district officials said Tuesday they still plan to spray about 66,000 acres in the county south of the American River later this week, once the winds slacken.
Last week's spraying prompted concern and scores of complaints about the potential health effects of airborne pesticides. Mosquito control officials have maintained that the concentrations of the chemicals used against the mosquitoes are minuscule, and that neither humans nor their pets should experience any adverse reactions.
Nevertheless, the mosquito control district will look for ways to better inform the public about any further aerial spraying and could revisit its entire control strategy this fall or winter, district trustees agreed at a board meeting Tuesday.
Once the height of the mosquito season passes, district manager David Brown told trustees, he will organize public workshops to discuss the guidelines the district uses to decide when and where to spray. The meetings could begin as early as October, he said.
Trustee David Tamayo said he doesn't necessarily want to reverse current policies but thinks it's important for the community to discuss when spraying is appropriate and why.
Trustees also called for a special committee to start looking for better ways to get the spraying message out, whether through a telephone notification system or other methods. The panel will include members of the public who have been active on the issue, Brown said.
The decisions came during a sometimes angry, hours-long meeting at which critics continued to challenge the aerial spraying and the way officials alerted the public.
One local contractor, Mark Fuoco, said he feared the spraying ultimately could spawn pesticide-resistant mosquitoes.
"There is an epidemic of madness and weird science going on here," he said.
Also at the meeting, a doctor said the state's poison control hotline can be a resource for anyone with questions about the potential health effects of the pesticide as well as specific symptoms.
Dr. Christian Sandrock, a UC Davis assistant professor of clinical medicine, said experts at the California Poison Control Hotline, at (800) 876-4766, are available to answer questions around the clock.
Hotline officials report what they consider credible pesticide-related symptoms to public health officials, he said. West Nile related calls to the hotline from the Sacramento region have been running four times higher than usual since Aug. 6, he said, but none have involved active symptoms that resulted from pesticide over-exposure.
As predicted, Central and Northern California communities are seeing the bulk of West Nile cases this year, while numbers have dwindled in Southern California.
In Los Angeles County, for example, five human cases have been logged so far this year; last year the county had 331 cases.
Among the 47 cases in Sacramento County, 17 people suffered neuroinvasive disease, the most serious consequence of the virus. Another 19 have been diagnosed with West Nile fever, which produces flulike symptoms. Eleven people showed no symptoms but tested positive for the virus, which was discovered in 10 of them after they donated blood.
The West Nile virus season is expected to last through September and into October, ending only with the first cold rain of the fall.
West Nile at a glance
2005 human cases
Sacramento County: 47
Stanislaus County: 23
Butte County: 7
Sutter County: 3
San Joaquin: 3
Yolo County: 2
Placer County: 1
Where to get information
To report a dead bird, call (877) 968-2473 (WNV-BIRD)
Sacramento and Yolo County residents can request mosquitofish, report untreated pools of standing water, get aerial spraying information and sign up for e-mail notification of local insecticide treatments by calling the Sacramento-Yolo Mosquito and Vector Control District at (800) 429-1022 or (916) 685-1022, or at www.fightthebite.net
Placer County residents can get West Nile information and obtain mosquitofish by calling the Placer Mosquito Abatement District at (916) 435-2140. For other information, contact the Placer County West Nile virus line at (530) 889-4001 or go to www.placermosquito.org or www.placer.ca.gov/wnv
Butte County residents can go to www.buttecountypublichealth.org, or call (800) 339-2941.
Other helpful Web sites:
Centers for Disease Control and Prevention: www.cdc.gov
California Department of Health Services: www.westnile.ca.gov
To reduce the risk of catching West Nile, the Sacramento-Yolo Mosquito and Vector Control District recommends:
Use an effective mosquito repellent containing ingredients such as DEET, Picaridin or oil of lemon eucalyptus.
Repair tears in door and window screens.
Drain standing water.
Wear long pants and long sleeves outdoors when practical.
Avoid being outside at dawn and dusk, when mosquitoes are most active.
About the writer:
- The Bee's Dorsey Griffith can be reached at (916) 321-1089 or firstname.lastname@example.org.