Search form

Sections

Changing Climate May Expand Valley Fever’s Impact

Fellowship Story Showcase

Changing Climate May Expand Valley Fever’s Impact

Valley fever feeds on heat. And as the average temperature ticks up with each passing decade, experts are concerned that the fungus’ footprint and impact are expanding, as evidenced by a rise in cases in areas far outside the hot spots of the Central Valley of California.

Changing Climate May Expand Valley Fever’s Impact
Reporting on Health Collaborative
Sunday, September 9, 2012 - 12:00pm

By Kellie Schmitt and Rebecca Plevin 

Valley fever feeds on heat.

And as the average temperature ticks up with each passing decade, experts are concerned that the fungus’ footprint and impact are expanding, as evidenced by a rise in cases in areas far outside the hot spots of the Central Valley of California.

In the soil, the cocci fungus lives on dead organic matter. Less rainfall and higher temperatures reduce overall vegetation, diminishing soil competition for the hardy fungus, scientists say. Cocci spores survive—even thrive—when the environment is drier and hotter since other competitors die off.

Cal State Bakersfield scientists are using satellite images to map areas that could be friendly to the fungus’ growth. They’re looking for similar vegetation to what is found on Sharktooth Hill, a popular site with for digging up bones from more than 5 million years ago. Because of that digging, researchers often inhaled spores from the soil and came down with valley fever.

So when the Cal State Bakersfield team finds areas that have vegetation that mirrors Sharktooth Hill, they paint that part of the map yellow.

Their map shows large swaths of Central California bathed in yellow, mostly undeveloped areas such as those along the I-5 and Highway 99 corridors or areas that have been burned by wildfires. Areas of high vegetation or those paved over typically don’t harbor the fungus, explained Jorge Talamantes, a California State University Bakersfield physics professor. 

“California is becoming dryer,” he said. “We have some climate changes. I think the environment where the fungus grows will expand.”


What Talamantes and other scientists are trying to figure out is whether the fungus itself is moving into new areas or whether it has long been there and is simply waiting for the right conditions to flourish.

Their computer mapping shows vegetation conducive to the fungus' growth farther north and east than valley fever cases normally occur. In theory, the soil near San Francisco would support the fungus’ growth, if it didn’t rain so much there. If rainfall or temperature patterns change, the reach of the fungus – and the illness – could expand farther, Cal State Bakersfield microbiologist Antje Lauer said.

Still, confirming these scientific theories would require more research funding and many more people working on the problem, she said.

 

The fever footprint grows

Paso Robles, a favorite spot among wine enthusiasts, tucked into the hills about 30 minutes from the Central California coast, doesn’t look like the typical valley fever zone. Bakersfield receives less than 6 inches of rain annually, making it one of the driest parts of the state. Paso Robles averaged 15 inches over the past decade and received more than 20 inches in each of the past two years.

Yet Paso Robles winemaker Todd Schaefer acquired a severe case of cocci in 2003 and has struggled since with a variety of health complications, including fungal meningitis. He was running a bulldozer through a vineyard when he breathed in the cocci spores in the dust, he believes. Over the past six months, Schaefer was only able to work two days.

"Doctors can't believe I'm still alive," he said. "They told me flat out, they can't believe it. But somehow I'm able to get by."

San Luis Obispo County, where Paso Robles is located, has seen a rise in the number of cases each year. It reported four cases of the disease in 1990, a year when only seven of 58 counties reported more than 10 cases. But by 2011, San Luis Obispo health officials reported 242 cases. Today, valley fever is rising in more than a third of the counties in California. The dramatic increase cannot be explained away as just as a sign of increasing awareness and better public health monitoring of the disease, health officials say.

Look at a map of valley fever cases over the years and it pops up in more states each year over the past decade. In 2001, nearly all cases were in the Southwest. By 2006, though, 13 states reported valley fever, including Michigan, Ohio, and Minnesota, which reported more cases than New Mexico and nearly as many cases as Nevada. Some of these cases are likely caused by travelers visiting the Southwest, but, as with everything related to valley fever, there has been very little funding of research into understanding the fungus’ reach.

Valley fever’s geographic footprint has even sparked concern from the nation’s space agency, which is studying a range of environmental issues near its operations in the Mojave desert to protect the health of the agency’s workers.

Senior scientific advisor Thomas Mace is testing a theory about how weather patterns affect the fungus. His research builds on University of Arizona findings and work by Kern County health officials that show that spikes in rainfall foster the fungus’ growth – like the unusually heavy rains seen in the Central Valley in 2010.  When a wet year is followed by a dry spell – like the one the Valley saw in 2011 – grasses and vegetation die off, leaving the more resilient fungus exposed and airborne.

Under that theory, a drier climate with occasional bouts of worsening storm patterns could spur more valley fever cases, turning a regional epidemic into a national one.

 

 

About This Series

This project results from a new venture – the Reporting On Health collaborative – which involves the Bakersfield Californian, the Merced Sun-Star, Radio Bilingüe in Fresno, The Record in Stockton, Valley Public Radio in Fresno and Bakersfield, Vida en el Valle in Fresno, the Voice of OC in Santa Ana and ReportingonHealth.org. The collaborative is an initiative of The California Endowment Health Journalism Fellowships at the University of Southern California’s Annenberg School for Communication and Journalism.

RELATED STORIES THIS WEEK

Public pushes for new thinking in valley fever research

Advocates of valley fever research have complained that the disease does not affect enough people to garner attention and funding; local doctors often misdiagnosed it; most data about the disease dates back decades; and the public has little knowledge of the disease and its impact.

Valley Fever Research Day Aims To Connect With Community

Community members are invited to attend Valley Fever Research Day Saturday at the UCSF Fresno Center for Medical Education and Research. The event is an opportunity for researchers to connect with community members who have been impacted by the fungal disease.

Federal, local officials hopeful for 'new era' in valley fever

Many questions about valley fever remained unanswered Tuesday as public health officials, physicians and politicians finished a two-day symposium on the disease, but many were hopeful that the summit will be a turning point.

Agencies to Launch Randomized Controlled Trial for Valley Fever

Directors of the National Institutes of Health and U.S. Centers for Disease Control and Prevention tell a packed valley fever symposium they are "serious" about finding a better treatment for the disease.

Just One Breath: Valley fever’s human and financial costs detailed in new study

The rate of people being hospitalized for valley fever has doubled in California over the past decade. Not only are more people being diagnosed with the disease but the cases are serious enough that more people are ending up in the hospital.

Valley Fever Symposium

On Monday, valley fever and the California area hit hardest by it will receive unprecedented attention in a two-day symposium led by U.S. Rep. Kevin McCarthy, R-Bakersfield. Rarely do the leaders of CDC and the NIH - two of the most powerful health institutions in the world - join the stage.

Just One Breath: Valley Fever Deserves More Ink in Scientific Journals

Valley fever hasn’t generated significant research funding. What will help move the needle? A sustained effort by public health advocates, clinicians and patients and their families and continued attention from media outlets.

Just One Breath: Valley fever movement could learn from health success stories

Strong patient advocacy raised the profile of breast cancer and HIV/AIDS. What lessons can those involved in the fight against valley fever learn from other, more high profile diseases?