Valley fever (coccidiomycosis)

January 2007     View PDF
Reprinted from University of Arizona’s Valley Fever Center for Excellence, US

Frequently asked questions

How do I get Valley Fever?
Valley Fever is acquired by inhaling one or more airborne spores of the fungus Coccidioides immitis. The spores are carried in dust particles from the soil by the wind when the desert soil is disturbed.

Who gets Valley Fever?
Anyone who lives, visits, or travels through the areas where the fungus grows in the soil (these areas are called endemic) may acquire valley fever. Military personnel who may be training in these areas are also at risk. People working in certain occupations such as construction, excavation, archaeological digging and other occupations which disturb soil in endemic areas may be at increased risk of exposure. Persons who pursue recreational activities such as biking or driving ATVs or 4-wheel drive vehicles in the desert may also be at increased risk. Earthquakes that have occurred in endemic areas of California have also resulted in increased cases of Valley Fever. Various domestic animals such as dogs and horses as well as wild animals are also susceptible.
I’ve lived in an endemic area for 10 years and am still skin test negative. Does this mean I have not had the disease?
You probably have not been in contact with the fungus. Skin test hypersensitivity usually remains life-long. Immunosuppression or an overwhelming infection may cause a negative response. Residents in the endemic areas of Phoenix, Arizona, and Bakersfield, California, have shown positive skin test rates of 30–40%, meaning that one-third of the residents tested had cocci sometime in the past. Among those who have never had Valley Fever, the chance of infection is about 3% per year, but the longer one resides in an endemic area, the greater the risk. In Southwestern U.S., there are approximately 100,000 new cases each year.

Is Valley Fever contagious?
NO! Valley Fever is contracted only by the inhalation of the fungal spores. Valley Fever is NOT spread from human to human, or animal to animal, or animal to human or human to animal. The spores change form in tissues of the body and are not contagious in tissue form.

How do I prevent getting Valley Fever?
There is no prevention or vaccine at this time. Avoiding activities associated with dust and airborne dirt of native desert soil is recommended, but it is not a certain means of prevention. Some occupations recommend wearing masks. Use common sense and stay out of the blowing dust.

Is there a cure for Valley Fever?
No. Researchers within our center and in the U.S. are working on the development of a prophylactic vaccine.

What is the incubation time?
Symptoms usually develop within 7–28 days after exposure.

What are the symptoms?
Most cases (60%) have no symptoms or only very mild flu-like symptoms and do not see a doctor. When symptoms are present, the most common are fatigue, cough, fever, profuse sweating at night, loss of appetite, chest pain, generalized muscle and joint aches particularly of the ankles and knees. There may also be a rash that resembles measles or hives but develops more often as tender red bumps on the shins or forearms.

Are hives associated with Valley Fever?
No. The rashes and bumps that are associated with Valley Fever are an immunologic response to the infection, not an allergic one. The rashes are called erythema nodosum and erythema multiforme depending upon the presentation.

What is the Valley Fever skin rash like?
Valley Fever can cause rashes that look several different ways. A common presentation is as painful or tender, slightly elevated red nodules or bumps, which may change color to bluish to brown and often occur on the legs, but may occur on the chest, arms and back. Another common form of rash is a red raised rash which may have blisters or somewhat pointed pimple-like bumps. It’s important to note that other diseases may also cause rashes that look the same. The names of the rashes are erythema nodosum (the most common) and erythema multiforme.

Will a skin test diagnose Valley Fever?
No. A skin test alone is not helpful in most cases. A skin test for cocci (usually called coccidioidin or spherulin) indicates exposure to the fungus, but not when it happened. Reactivity is lifelong. An individual living in an endemic area and having a positive skin test could have been exposed years before being tested. However, a positive skin test on a patient from a non-endemic area, having recently returned from the Southwest or other endemic areas, probably would indicate recent exposure. Generally, a skin test is not considered a means of diagnosis, but a tool of epidemiologic studies.

Will Valley Fever cause a positive TB (tuberculin PPD) skin test?
No. The tuberculosis and Valley Fever skin tests do not cross react. The presence of tuberculosis will not cause a positive cocci skin test nor will the presence of Valley Fever cause a positive tuberculin test.

How is Valley Fever diagnosed?
Diagnosis is obtained by use of a specific blood test (called a coccidioidin or cocci serology) which measures the level or titer of antibodies to the fungus. A positive titer is usually measured or reported in dilutions of the patient’s serum that continue to react to the fungal antigen. Titers are reported as 1:2, 1:4, etc. In early disease, the cocci serology must be repeated in 2–4 weeks if negative because the antibody level is too low to be detected. Culture of sputum, tissue, biopsies, or body fluids or histopathology (microscopic) evidence from the same sources are diagnostic.

How do I get a Valley Fever test?
The doctor must order the test for you.
Is a chest x-ray necessary if a cocci serology blood test is drawn?
The doctor uses the x-ray as a means of diagnosis as well as a means of following the progress of the disease.

Can Valley Fever be misdiagnosed?
Yes. Depending upon the symptoms, it may be confused with cancer, tuberculosis, chronic obstructive pulmonary disease, chronic fatigue syndrome and others. However, if the specific blood test to measure antibodies against the fungus is performed along with chest x-rays, travel history through the Southwest, and when appropriate skin test results are performed and considered, a diagnosis is made. The isolation in laboratory culture of the causative fungus from sputum, tissue or body fluids is diagnostic as is the presence of the diagnostic spherules as seen in histopathology.

What kind of doctors know most about Valley Fever?
Infectious diseases specialists are probably the most familiar with the disease depending upon in which part of the country you live. Pulmonary specialists and most primary care and family practitioners in endemic areas are versed in the diagnosis and treatment. However, physicians in other parts of the country seldom see cases of Valley Fever and, therefore, do not consider it in diagnosis unless a travel history through the Southwest is given. The patient should emphasize he/she knows about valley fever and wants to be tested. Should you desire a medical referral in your area, call the Valley Fever Center for Excellence 520-629-4777. Your physician is also encouraged to call at the same number to consult about diagnosis and treatment with our specialist.
I don’t live in an endemic area, but I need a Valley Fever specialist.

How do I find one?
Call the Valley Fever Center for Excellence at 520-629-4777 and we will try to find a referral physician for you.

How long will I be sick?
The length of illness depends on the severity of the infection. As said before, most cases have no symptoms, others may take months to even more than a year to resolve. Persons frequently complain of fatigue and joint aches lasting months. The chronic forms of Valley Fever may last years, with a waxing and waning course.

Is there a chronic form of Valley Fever?
Yes. Patients with this manifestation present with chronic systemic symptoms such as low grade fever, weight loss, cough, chest pain and hemoptysis. These symptoms are often indolent and resemble tuberculosis when coupled with x-ray findings.

I had Valley Fever years ago. Can I get it again?
Usually a life-time immunity is acquired from an infection which means you don’t get it again. However, occasionally, changes in the person’s immune system brought about by other diseases or treatments which lower or suppress the immune system can allow a reactivation or reinfection.

What are lung nodules and do they go away?
Lung nodules are the result of pneumonia caused by Valley Fever. Nodules are small residual patches of infection that generally appear as single lesions, typically one to one and one-half inches in diameter. Patients who have no symptoms as well as patients who do have symptoms may develop nodules. Approximately 5–7% of patients with cocci pneumonia will form sharply circumscribed singular nodules. If it is documented that the nodule is caused by valley fever, no other treatment is required. However, because the nodule may appear to be cancer, a biopsy or removal may be necessary. Nodules caused by cocci may remain a life-time.

The doctor says I have a cavity. Do I need surgery?
Cavities occur in about 5% of patients with pulmonary cocci. The typical cocci cavity is thin-walled and solitary. Coccidioidin cavities are commonly asymptomatic (do not cause symptoms) and about 50% will disappear within 2 years of their occurrence. A cavity may persist for years with minor changes. About one-third of the patients with cavities may experience hemoptysis (coughing blood). The hemoptysis is often recurrent but generally not life-threatening. If rupture of the cavity is a large possibility, surgical removal may be necessary.

When a person contracts Valley Fever, will he/she always show a scar on their chest x-ray?
Scarring is frequently found and correlates to the severity of illness. Many persons have such a mild case they have no symptoms and no scarring.

I have pneumonia. Will antibiotics help?
Coccidioidin pneumonia is not treated with routine antibiotics (such as penicillin, cephalosporin, erythromycin) because it is caused by a fungus and “regular” pneumonia is caused by bacteria. There are antifungal medications that may be used to treat Valley Fever.

Why won’t my doctor prescribe any medication when I feel really sick?
Before the availability of antifungal medications, the natural history of initial pulmonary infections was determined to resolve in at least 95% of patients. Studies have not been completed yet to determine if drug therapy hastens the resolution of immediate symptoms or prevents subsequent complications. The physician usually monitors the progress of the patient by chest x-rays, following the cocci serology (blood test) titer and the severity and duration of symptoms. This may require frequent visits to the doctor. If weight loss and night sweats continue, infiltrates in the lungs enlarge, and the inability to work persists, antifungal medication usually is considered.

Which antifungal medications are used to treat Valley Fever?
The “azole” family of antifungal drugs are frequently used. These are oral preparations of ketoconazole, itraconazole and fluconazole. Each have various side effects and may be expensive. The azoles do not kill the fungus but they control it. Amphotericin B is an antifungal medication that is used in serious and culminant infections. It may be administered intravenously or intrathecally (injecting the medication directly into the fluid surrounding the brain).

What are the side effects of antifungal drugs?
The common side effects of ketoconazole are nausea and vomiting, gynecomastia (enlargement of male breasts) and decreased libido. The common side effects of itraconazole and fluconazole are nausea, headache, skin rash, vomiting, abdominal pain and diarrhea. Side effects resulting from treatment with the azoles usually resolve with the discontinuation of the drug. Amphotericin B may have several side effects, most of which may occur during administration and then pass. Newer forms of Amphotericin B have been developed to ease symptoms during administration. Amphotericin B may effect the kidneys and requires close monitoring. Additional side effects with all antifungal medications may occur. Consult with your doctor, pharmacist and/or package insert for further details.

How long do I have to take antifungal medication?
The length of treatment depends on the severity of symptoms and disease and complications of the disease. Some patients take antifungal medication for a few months; others need life time therapy.

What does immunocompromised mean? How does this affect a Valley Fever infection?
A person is immunocompromised when his or her immune system (the body’s defense against disease) is not intact. This may be the result of diabetes, chronic use of corticosteroids, cancer, chemotherapy, HIV/AIDS, organ transplantation, pregnancy or even aging. Usually the body is able to fight the fungus and recover without medication. If the immune system is compromised, it is unable to control the infection and allows the infection to spread from the lungs to other organs. The spread of infection from the lungs to other parts of the body is called dissemination.

What is dissemination?
Dissemination is the spread of the fungal infection from the lungs to other parts of the body. The most common sites of dissemination in Valley Fever are skin, bones, joints and brain meninges. Cocci meningitis is the most lethal.

Who is at risk of dissemination?
While there is no racial or gender differences in susceptibility or who contracts the primary infection, there are differences in risk of dissemination. Men have a higher rate of dissemination than women. African Americans and Filipinos have several times higher rate of dissemination in the U.S. Native Americans, Hispanics and Asians may also have a higher rate of dissemination than the general public. Others at increased risk of disseminated disease are those with immune system deficiencies such as organ transplants, Hodgkin’s disease patients, diabetics, pregnant women in their third trimester, patients on chronic corticosteroid therapy or chemotherapy, cancer patients and HIV/AIDS patients.

What are spherules?
Spherules are the form that the fungus takes in tissue. In nature the fungus grows in soil and appears in the mycelial form similar to bread mould. Portions of the hair-like mycelia break off into arthroconidia (“spores”) and become airborne when the soil is disturbed. The arthroconidia are extremely small and light and may be carried many miles by the wind. Fifteen trillion of the arthroconidia would fit into a cubic inch. There has been documentation of a severe dust storm occurring in Bakersfield, CA, an endemic area, blowing as far north as San Francisco where it is not normally found, and causing an epidemic in the Bay area. It demonstrates the two forms the fungus takes. In the histopathology section of this website, additional microscopic photographs show the spherule form in tissue.

Is Valley Fever contagious from an open lesion?
No. The tissue phase of the fungus Coccidioides immitis is a spherule. The infectious phase is when the “spores” are inhaled from the air.

Do pigeons spread Valley Fever?
No. Pigeons do carry cryptococcosis which also is a fungal disease.

Do chickens spread Valley Fever?
No. Chickens spread histoplasmosis, a fungal disease found in the Midwestern U.S.

I have asthma. Are my chances of getting Valley Fever greater?
No. The risk of contracting Valley Fever is no greater because you have asthma. You must inhale the spores from the fungus in order to become ill.

I have COPD. Are my chances of getting Valley Fever greater?
No. The risk of contracting Valley Fever is no greater for a person with chronic obstructive pulmonary disease than anyone else.

Are there times of the year when chances of contracting Valley Fever are greater than others?
Yes. Although blowing dust may carry the infectious spores of cocci anytime throughout the year, there are times which we call peak seasons for cocci. These vary with the seasons of the year and appear to be related to the amount of rainfall. In Arizona, the peak seasons occur from June through August and from October through November. In California, the summer months of June through August have the most cases reported.

I read about a “sulfur cure”. Does it work?
There have been no studies to corroborate the claims made. The time period in which “cures” are claimed is probably the time that the body would recuperate on its own. The use of this product instead of medical care is not recommended.

How can I boost my immune system?
Rest and good nutrition are recommended. Physicians may recommend some herbals.

I am immunocompromised because of AIDS. Is it OK to travel in an endemic area?
The risk is probably no greater than for anyone else. However, the longer you remain in an endemic area, the more chances of exposure. In Arizona, it is estimated that the average risk of annual infection of the resident population is 3%. That means each year only 3% of the susceptible population will contract Valley Fever. If you are particularly concerned about getting Valley Fever, try to avoid activities associated with dust and airborne dirt of native desert soil. Stay indoors during dust storms.

Does the fungus lay dormant in the body?
In many cases the fungus does remain in the body. If the person’s immune system is greatly immunocompromised, a reactivation of the disease may occur. This has been found to occur in many of the disseminated cocci patients with AIDS.

Do birds get Valley Fever?
In reviewing the records of the Arizona Veterinary Diagnostic Laboratory for the last 50 years and the scientific literature, we were unable to find a case of Valley Fever in any domestic, wild, or exotic avian species. From this, we conclude that Valley Fever does not cause disease in birds.

What is Valley Fever?

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