Dust Cloud After Quake Caused Valley Fever, Scientists Conclude : Health: Windblown debris is blamed for flu-like ailment. Researchers will declare the Simi Valley outbreak the first known to be linked to a temblor.

A cloud of dust rising from the Santa Susana Mountains after the Jan. 17 earthquake very likely brought on the unprecedented outbreak of valley fever that plagued Simi Valley and much of eastern Ventura County this spring, scientists say.

After five months of interviews and analysis, scientists at the Centers for Disease Control have concluded that residents caught in the dust cloud were most likely to contract the flu-like ailment.

There were 203 cases of valley fever diagnosed among Ventura County residents in the weeks after the quake. That contrasts with 52 cases for all of 1993. One 71-year-old Simi Valley man died in this year’s outbreak.

Researchers believe that disease-bearing spores were stirred up in landslides caused by the quake and its aftershocks, then swept with the wind across the county.

“The spores are often in the ground, but they’re pretty much just sitting there,” explained Richard Spiegel, a researcher with the Atlanta-based CDC. “Basically from all the ground shaking, that unleashed significantly more dust than you might normally have.”

The CDC team will declare the Simi Valley outbreak the first known to be related to an earthquake when it presents conclusions at a Stanford University conference Thursday.

But one local health official is disputing the findings.

‘Piddle paddle,” said Shirley Fannin, director of disease control programs for Los Angeles County. “I have to tell you I disagree.”

The San Fernando Valley, hardest hit by the magnitude 6.8 quake, had little change in its rate of disease, she said. Only 46 cases have been reported this year.

The disease, a fungal infection known to scientists as coccidioidomycosis, manifests no real symptoms in about 60% of cases. Other victims experience flu-like exhaustion, coughing, even high fevers and pneumonia. Older people are usually more severely affected.

Fannin believes that Ventura and the CDC overreacted to the valley fever scare.

“They called everything with a positive lab test for antibodies a case of valley fever,” she said. She said tests would have been positive if a patient had contracted the illness any time in the past several years.

Los Angeles County health officials did not count a case as valley fever until further tests or active symptoms confirmed the disease, Fannin said.

CDC researchers defended their findings, saying all of the Ventura County cases were confirmed with blood tests. The direction of the wind or the amount of fungus found in paved-over San Fernando Valley could account for the low incidence there, said Eileen Schneider, a CDC epidemiologist from San Diego.

Also, she said the San Gabriel Mountains northeast of the Valley did not have the same landslide activity that occurred in the Santa Susana range near Simi Valley. While the northern edge of the Valley also borders the Santa Susanas, winds were blowing toward Simi Valley after the quake, Schneider said.

The quake and each of its aftershocks brought up a cloud of ocher dust from the canyons around Simi Valley. The highest concentrations of valley fever cases lay in the neighborhoods near the base of the mountains north of the city, she said.

A map hanging in Ventura County’s Public Health Services Department shows graphically how valley fever spores may have spread. Dozens of push pins are clustered in the Simi Valley.

The pins fan out on a southwest course, with several cases in Thousand Oaks, and thin out farther from the mountains on the Oxnard Plain.

Ventura and CDC officials believed from the start that the earthquake had kicked off the valley fever outbreak, but conducted tests this spring aimed at proving their theory.

They asked valley fever victims if they had been in a dust cloud, and more than a third responded that they had.

They tested a random sample of the Simi Valley population for overall exposure to the fungus causing valley fever and found fewer than 6% had been exposed. They tracked the cases and found that the incidence of the disease returned to normal levels about two months after the quake.

Finally, they studied the age, race and other demographic factors for victims and found nothing to suggest another reason for the outbreak, Schneider said.

The disease takes it name from the San Joaquin Valley, where it is most commonly found. In recent years, Kern County has been plagued with thousands of cases of the ailment, particularly among farm workers.