What Is Valley Fever?
Valley fever, also known as coccidioidomycosis, is an infection caused
by the Coccidioides fungus. This fungus is commonly found in soil and
dust in the southwestern United States and in parts of Mexico, Central America,
and South America. Coccidioides fungus was also recently discovered in central
California and south-central Washington.
The spores are most likely to form in warm, wet soils after periods of
heavy rainfall. The spores are then stirred into the air by anything that
disrupts the soil, such as wind, construction, and farming. People can then
contract valley fever by breathing in these tiny, airborne fungal spores.
The fungal infection normally starts in the lungs. In rare cases, the
infection can spread to the rest of the body. Some people might also develop a chronic form of coccidioidomycosis. This
means the symptoms occur repeatedly for extended periods of time.
What Are the Symptoms of Valley Fever?
Most people who are exposed to the Coccidioides fungi don’t
experience any symptoms. When symptoms do occur, they appear within one to
three weeks after the initial exposure. The symptoms of valley fever often
resemble those of the flu. However, they can vary depending on the severity and
type of valley fever contracted. The symptoms also depend on the health status of
the person who contracts the illness.
Acute coccidioidomycosis is the most common form of valley fever. It
causes symptoms that are similar to those of the common cold or flu. These
- night sweats
- joint pain
- painful rash
Most cases of acute coccidioidomycosis are mild. Symptoms typically go
away within a few weeks. In some cases, however, the infection can become more
severe and develop into the disseminated or chronic form of coccidioidomycosis.
Disseminated coccidioidomycosis is the most serious form of valley
fever. However, it is very rare, accounting for less than one
percent of cases. It occurs when the fungal infection spreads from the
lungs to other parts of the body, including:
- membranes that surround the brain and spinal
Once these organs become infected, the symptoms of valley
fever may become more severe. Depending on the parts of the body that are
affected, additional symptoms may also develop. These symptoms include:
- skin ulcers
- painful and swollen joints
- decreased appetite
- enlarged lymph nodes
- change in mental state, including irritability
The coccidioidomycosis infection may become chronic if it doesn’t go
away completely. This means that symptoms may return repeatedly or persist for
extended periods of time. The symptoms of chronic coccidioidomycosis include:
- low grade fever
- chest pain
- blood tinged sputum
What Causes Valley Fever?
People can contract valley fever by inhaling dust from soil that
contains Coccidioides fungus. There are two types of Coccidioides
fungus that can cause valley fever: Coccidioides immitis and Coccidioides
posadasii. These fungi are present in various parts of Mexico, Central
America, and South America. They are also commonly found in the dry desert soils
of Arizona, Nevada, Utah, Texas, New Mexico, south-central Washington, and the
San Joaquin Valley of central California.
Like other types of fungi, Coccidioides species have a complex
life cycle. They grow as mold in soil and develop long filaments, or thin
series of cells. These filaments can break off into airborne spores when the
soil is disturbed by weather, farming, or construction. The fungal spores are
extremely small and can be carried hundreds of miles by the wind. When the spores
are inhaled, they can reproduce inside the lungs and perpetuate the cycle of
Who Is at Risk for Valley Fever?
You are at risk for valley fever if you live or spend time in an area
where Coccidioides fungi are commonly found. Your risk of
contracting the infection is even higher if you are in an area where soil
containing Coccidioides fungi is often disturbed by weather,
farming, or construction.
You have an increased risk of getting the chronic or disseminated form of
valley fever if you:
- have a weak immune system
- have diabetes
- are an older adult
- are pregnant
How Is Valley Fever Diagnosed?
Valley fever is difficult to diagnose solely on the basis of symptoms,
as they often mimic those of other diseases and illnesses. To make an accurate
diagnosis, your doctor may test a sample of your mucus or blood to check for
the presence of Coccidioides fungi in your body. Your doctor may also
perform an X-ray to see if there are any changes in your lungs consistent with
an infection by Coccidioides.
If you have severe symptoms and your doctor suspects the infection has
spread throughout your body, they may order the following tests:
- bronchoscopy with lavage
- spinal tap
How Is Valley Fever Treated?
Treatment for valley fever may include home care, medication, or
surgery, depending on the severity of symptoms.
Most people get better without treatment. To speed up recovery time,
however, doctors often recommend home treatments. These can include bed rest,
drinking plenty of fluids, and taking over-the-counter pain relievers such as
ibuprofen and acetaminophen.
When symptoms don’t improve with home remedies, doctors prescribe
antifungal medications to kill the fungus. These drugs are also used to treat the
chronic or disseminated form of valley fever. The most commonly prescribed antifungal
drugs are fluconazole
(Diflucan) and itraconazole
(Sporanox). However, voriconazole
(Vfend) and posaconazole
(Noxafil) may be used to eliminate more serious fungal infections.
In rare cases, surgery may be required to remove the infected areas of
the lungs. This is usually only performed for people who have chronic or severe
What Is the Outlook for Someone with Valley Fever?
The outlook for people with valley fever depends on their overall
health and the type of infection. Most people with the acute form of
coccidioidomycosis completely recover without any complications. People with the
chronic form also usually recover with treatment, but they may experience
relapses in the future.
Though few people develop the disseminated form of valley fever, they
are more likely to experience life-threatening complications. People with
conditions that affect their immune system are at higher risk of developing the
disseminated form. This includes people with HIV or AIDS, patients on active
chemotherapy, and diabetics.
How Can Valley Fever Be Prevented?
Valley fever can’t always be prevented. However, you can limit your
exposure to the Coccidioides fungus by:
- wetting soil with water before digging or
- wearing a filtration mask that can filter 0.4
micrometer size particles
- covering open dirt areas around your home with
grass or plants
- keeping your doors and windows closed during
dust storms or on windy days