As the number of West Nile cases in California continues to climb, more and more residents are asking their doctors for tests to pin down a possible diagnosis.
The problem for patients is that doctors are unlikely to order the blood test because the vast majority are mild cases and because they have no specific treatment for the virus.
The statewide West Nile caseload jumped to 416 Tuesday, up more than 12 percent from Friday's total of 370. Of the 46 new cases, 14 were reported in Sacramento County, representing a 17 percent rise since Friday when the county's tally was 83.
The West Nile death toll has remained at eight since Friday, when the state announced the deaths of a Sacramento County man and Fresno County woman. Sacramento County remains the state's epicenter of the virus, and California has by far the highest number of cases in the nation.
Health officials acknowledge that high levels of the virus in mosquitoes - as well as intense media attention to the human disease threat - have prompted some to seek medical attention.
"Everyone is reading about this every day. They hear the horror stories. It's understandable they want to get tested," said Dr. Carol Glaser, chief of the viral disease laboratory at the state Department of Health Services, "but we don't think the worried (but healthy) should be tested."
As for those with possible symptoms of West Nile fever such as body aches, fatigue and fever, Glaser recommends testing only if the patient has been sick for a week or more, signaling a more serious infection.
Because the test is unlikely to detect the virus within the first couple of days of infection, an early test could produce a false negative result. Also, most people who get infected don't get seriously ill, and even for those whose symptoms linger there is no known treatment.
"We are trying to (test) those sickest with West Nile fever," she said, "but we want to weed out a benign illness that lasts one to three days."
The limited testing recommendations help explain why actual case numbers do not jibe with what researchers know about the prevalence of infection in the general population.
Health officials rely on studies done in recent years on large numbers of asymptomatic people in areas where the diseases has been rampant, including New York City, Romania and Israel, to determine prevalence. A similar study is under way in Southern California.
So far, the statistics generally have been consistent: Only 20 percent of those infected with the virus will experience symptoms, and only one in 150 people infected will get a neuroinvasive condition, the most serious complications of the disease.
Glaser is confident that doctors are catching the lion's share of patients with a neuroinvasive condition, such as encephalitis or meningitis caused by the virus.
As of Tuesday, 127 of the state's cases have been classified as neuroinvasive West Nile disease, representing a little less than a third of all cases reported. In Sacramento County, 32 are neuroinvasive cases, also about one-third of all cases reported.
Dr. Jack Wood, an emergency room doctor at Mercy San Juan Medical Center, said the hospital has seen an increase in the number of people requesting the West Nile test since the first cases were reported locally in early August.
"The answer used to be, if they didn't meet the criteria, we were not ordering it unless we were concerned they had West Nile virus," he said.
That stance has shifted in recent days, he said, as Sacramento County has become "a hotbed for West Nile virus."
Because of the higher infection rates here, doctors are more suspicious when they see severe and lingering flulike symptoms and more likely to test for the disease, he said.
Some residents still are unhappy with the approach. Judith Rippetoe of Foothill Farms said that after coming down with a bad cough, fever, headache and body aches, she went to the hospital, where she was diagnosed with bronchitis. Still, the 52-year-old wanted a West Nile test.
"The doctor said we don't test for West Nile unless there is evidence of encephalitis," she said. "I was astounded. I just thought I would like to know."
Dr. Glennah Trochet, Sacramento County health officer, said testing should be reserved for patients whose doctors are considering West Nile virus as a diagnosis.
She said the county, which runs its own laboratory, will test blood samples without charge to either the patient or doctor. Private laboratories, such as Quest Diagnostics, also test for West Nile, but only with orders from a physician, she said.
West Nile at a glance
Figures released Tuesday show the number of 2005 West Nile cases continue to rise, hitting 416 statewide.
Regional counties: Sacramento, 97; Stanislaus, 49; San Joaquin, 11; Placer, 11; Butte, 10; Yolo, six; Sutter, four; Tehama, two; Nevada, one; Plumas, one; Solano, one; Yuba, one.
Ground spraying to begin in Roseville
The Placer Mosquito Abatement District has delayed plans for ground spraying by truck in south Roseville until Thursday, Friday and Saturday. Weather permitting, the spraying will occur from 1 a.m. to 4 a.m. The areas to be sprayed are:
Thursday: Along roads bounded by Vernon Street, the Placer County line, Sunrise and Douglas boulevards.
Friday: Along roads bounded by Harding Boulevard/Galleria Boulevard, Douglas Boulevard, Vernon Street, Washington Boulevard, Pleasant Grove Boulevard and Roseville Parkway.
Saturday: Along roads bounded by Washington Boulevard, Pleasant Grove Boulevard, Foothills Boulevard, Cirby Way and Vernon Street. Roseville and South Placer County residents who want to be placed on Placer Mosquito Abatement District's "no spray" list should notify the district, preferably by e-mail at email@example.com, or by calling the district at (916) 435-2140 and providing their name, telephone number and property address.
Where to get information
To report a dead bird, call (877) 968-2473.
Sacramento and Yolo counties: 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 information and obtain mosquitofish by calling the Placer Mosquito Abatement District at (916) 435-2140.
For updates and changes to the ground-spraying schedule, go to www.roseville.ca.us or call (916) 435-2140.
For other information, call the Placer 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.
Anyone with concerns about the health effects of spraying can call the California Poison Control number at (800) 876-4766.
Other Web sites: Centers for Disease Control and Prevention, www.cdc.gov; state Department of Health Services, www.westnile.ca.gov.
To reduce the risk of catching West Nile virus, 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.