Valley Fever

 

• Valley fever is an emerging and sometimes deadly fungus infection.
• The valley fever fungus lives in soil and is spread through the air.
• Farmers, construction workers, and others who engage in activities that disturb the soil are at highest risk for valley fever. People with weak immune systems and persons of certain racial groups can become seriously ill from the infection.
• Valley fever is treatable with fungus-killing medicines.
• Persons at risk for valley fever should avoid exposure to dust and dry soil in areas where valley fever is common.

 

 What is valley fever?

Valley fever is another name for the sometimes deadly infection coccidioidomycosis. It is called valley fever because the organism that causes it is commonly found in the soil of the southwestern United States, Mexico, and parts of Central and South America.

Valley fever usually affects the lungs. When it affects other parts of the body, it is called disseminated valley fever.

 

What is the infectious agent that causes valley fever?

Valley fever is caused by Coccidioides immitis, a fungus. The fungus produces spores that can be inhaled when they get into the air. Spores are hardy forms of the fungus that can live for a long time in harsh environmental conditions such as heat, cold, and drought.

 

Where is valley fever found?

The valley fever fungus grows naturally in soil in the southwestern United States and in parts of Central and South America.

 

How do people get valley fever?

Valley fever is spread through the air. If soil containing the valley fever fungus is disturbed by construction, natural disasters, or wind, the fungus spores get into the air. People can breathe in the spores and get valley fever. The disease is not spread from person to person.

 

What are the signs and symptoms of valley fever?

About 60% of infected persons have no symptoms. The rest develop flu-like symptoms that can last for a month and tiredness that can sometimes last for longer than a few weeks. A small percentage of infected persons (<1%) can develop disease that spreads outside the lungs to the brain, bone, and skin (disseminated disease). Without proper treatment, valley fever can lead to severe pneumonia, meningitis, and even death.

 

How is valley fever diagnosed?

Valley fever is diagnosed with a blood test or culture.

 

Who is at risk for valley fever?

Anyone can get valley fever, but people who engage in activities that disturb the soil are at increased risk. They include:

• Farmers
• Construction workers
• Military personnel
• Archaeologists

People with weakened immune systems are at increased risk for disseminated disease. HIV infection, as well as medical advances like chemotherapy and organ transplants, cripple the immune system and weaken resistance to fungus infections. Others at increased risk for disseminated disease are: elderly persons, African-Americans, Asians, and women in the third trimester of pregnancy.

 

What is the treatment for valley fever?

Valley fever can usually be treated with fungus-killing medicines.

 

How common is valley fever?

An estimated 50,000 to 100,000 persons develop symptoms of valley fever each year in the United States, with 35,000 new infections per year in California alone. In Arizona, the incidence of reported cases was 15 per 100,000 in 1995.

 

Is valley fever an emerging infectious disease?

Yes. Valley fever is on the rise because of the growing number of people who are moving to areas where the disease is common (such as Arizona) and increases in the number of persons with weakened immune systems.

Recent natural disasters have also triggered a rise in valley fever cases. The central valley of Southern California had a 4-year epidemic of valley fever in the early 1990s after a severe drought. Cases of valley fever also increased in persons exposed to billowing dust released by the January 1994 earthquake in Northridge, California.

 

How can valley fever be prevented?

There is no vaccine against valley fever. Persons at risk for valley fever should avoid exposure to dust and dry soil in areas where valley fever is common.

 

This fact sheet is for information only and is not meant to be used for self-diagnosis or as a substitute for consultation with a health-care provider. If you have questions about the disease described above, consult a health-care provider.