San Jaoquin 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. The disease is not communicable; it cannot be passed from person to person.
What is Valley Fever?
What is the infectious agent that causes Valley Fever?
Where is Valley Fever found?
How do people get Valley Fever?
How soon after exposure do symptoms appear?
What are the signs and symptoms of Valley Fever?
How is Valley Fever diagnosed?
Who is at risk for Valley Fever?
What is the treatment for Valley Fever?
Can there be complications with Valley Fever?
How common is Valley Fever?
Is Valley Fever an emerging infectious disease?
How can Valley Fever be prevented?
What is Valley Fever?
Valley Fever is another name for the sometimes deadly infection
coccidioidomycosis. It is called San Joaquin Valley Fever
because the organism that causes the disease was identified
in Kern County California. 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's 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 fungal spores get into the air. People
can breathe in the spores and get Valley Fever. The disease
is not spread from person to person.
How soon after exposure do symptoms appear?
Symptoms of the disease usually start within one to four weeks
after exposure. Disseminated disease may develop years after
the primary infection (even when the primary infection was
so mild that the patient does not remember having it).
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 a disease
that spreads outside the lungs to the brain, bone, and skin. 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 sputum 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?
Mild cases of coccidioidomycosis usually resolve without
treatment. For severe cases, anti-fungal medications are needed.
Disseminated coccidioidomycosis is fatal if untreated, but
death can also occur in some patients even when medical treatment
is received.
Can there be complications with Valley
Fever?
One complication of this infection is called erythema nodosum.
This occurs most commonly in Caucasian females and should be
diagnosed by a physician. Another complication of this infection
is permanent damage to the lungs. Approximately one out of
a thousand cases of coccidioidomycosis will progress to disseminated
coccidioidomycosis, which is the most severe form of the disease.
People with disseminated disease can form lesions in the lung
and abscesses throughout the body. These abscesses tend to
form in the subcutaneous tissues, skin, bone and the central
nervous system (the brain and spinal cord).
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.