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Coccidioidomycosis is an infection caused by breathing in the spores of a fungus Coccidioides immitis found in soil in desert regions of the southwestern U.S., Mexico, and Central and South America. Sometimes called Valley Fever or Desert Fever because of its prevalence in farming valleys, these fungi resist drying and easily become airborne. It usually affects the lungs but can spread and affect many organs.
The disease can have an acute, chronic, or disseminated form.
Incidence; Risk Factors
The incidence of both acute pulmonary coccidioidomycosis and the chronic disease is around 1 in 100,000 people.
Coccidioidomycosis is endemic in the western hemisphere from California to Argentina. Coccidioidomycosis is also being recognized outside these areas as travelers pass through. Former residents of endemic areas suffer reactivation, and natural disasters such as earthquakes and dust storms create new epidemics.
Risk of infection is greatest on windy days when the soil is dry or when the soil is disturbed by activity. An example of such infectivity was noted following a large California dust storm after which 15 counties reported a tenfold or more increase in cases of coccidioidomycosis.
Areas outside of the US with a higher risk are characterized by semi-arid climates with hot summers and alkaline soil include northern Mexico and Central and South America.
Diseases and conditions that alter immune responses also predispose those affected to dissemination and serious disease. Pregnant women are at special risk for disseminated coccidioidomycosis.
Filipinos have the highest risk of dissemination, about 10-170 times the risk of whites. Blacks and Hispanics also have a higher risk of dissemination than whites. Blacks have a 5 times higher risk of developing meningitis than whites; Filipinos have a 10 times higher risk of developing meningitis than whites. Mortality rate is 5 times greater for blacks than for whites. The incidence is equal in males and females and persons of any age may be affected. In disseminated disease, the mortality rates in newborns and infants are much higher than those in children, adolescents and adults.
Signs & Symptoms
Coccidioidomycosis usually develops 1-4 weeks following exposure. About 60% of infections cause no symptoms and are only recognized by a positive coccidioidin skin test. In the remaining 40% symptoms range from mild to severe. Although the symptoms are very nonspecific, a level of suspicion should be maintained for those who live in or have traveled to endemic areas or have persistent symptoms.
When inhaled, as few as 10 surviving spores can cause infection and mature as quickly as 48-72 hours into an active fungal state. Although coccidioidomycosis is not contagious, lab personnel who handle specimens must take precautions to avoid contracting the illness.
Following inhalation and maturation of the cocci, humoral immunity predictably begins with immunoglobulin M (IgM), then IgG. Cellular immunity, particularly T-cells, becomes a key factor in determining recovery from coccidioidomycosis. A respiratory infection ensues.
The majority of patients recover from the respiratory infection with no or minimal consequences. Some develop complications in the lungs, such as tissue death or abscesses. Persistent pulmonary disease may manifest as persistent bronchitis and pneumonia. A subset of patients will develop infection outside the lungs: the infection spreads through blood either during the primary infection or as a reactivation from a chronic pulmonary site.
Areas affected outside of the lungs may include blood cell generating tissues, skin, kidneys, bones, the central nervous system and heart muscle. Disseminated disease can involve nearly every organ and can be especially dangerous in the immune compromised host. More often, in chronic cases, the disease progresses slowly.
Acute pulmonary coccidioidomycosis is almost always mild, with few or no symptoms, and resolves without treatment. The incubation period is 10 to 30 days.
Chronic pulmonary coccidioidomycosis can develop 20 or more years after initial infection which may not have been recognized, diagnosed, or treated. Infections (lung abscesses) can form and rupture releasing pus (empyema) between the lungs and ribs (pleural space).
In disseminated disease, extension of infection to the bones, lungs, liver, meninges, brain, skin, heart, and pericardium (sac around the heart) may take place.
Any of the following may be symptoms:- wheezing
- cough
- blood-tinged sputum
- chest pain, varies from mild sense of constriction to severe
- fever
- chills
- night sweats and excessive sweating
- headache
- muscle, joint, neck, shoulder stiffness
- muscle aches (myalgia)
- rash, may be painful, red, on lower legs (erythema nodosum)
- loss of appetite
- weight loss
- change in mental status
- sensitivity to light
Additional symptoms that may be associated with this disease:Diagnosis & Tests
Skin tests, blood tests, and sputum cultures can be used for the diagnosis:- sputum smear (KOH test)
- sputum culture
- serum coccidioides complement fixation titer
- CBC with differential shows elevated eosinophils
- chest X-ray
- coccidioidin or spherulin skin test.
Treatment & Prevention
The acute disease almost always goes away without treatment. Bedrest and treatment of flu-like symptoms until fever disappears may be recommended.
The results of medical therapies for coccidioidomycosis are unpredictable. Antifungal therapy for coccidioidomycosis often is less certain than for other fungal diseases. Fortunately, only about 5% of patients require therapy. Common drugs used include Amphotericin B, Diflucan, and Nizoral.
Prognosis; Complications
About 40% of those infected develop symptomatic disease, usually pulmonary. About 90% will resolve their pulmonary maladies without lasting consequences. Some 10% of patients will go on to harbor pulmonary lesions and nodules and about 1% develop disseminated disease.
The outcome in limited disease is likely to be good. With treatment, the outcome is usually good although relapses may occur. People with disseminated disease have a high death rate.
Meningitis occurs in 30 to 50% of cases of disseminated disease. The course of the disease may be rapid for immunosuppressed patients. Other possible complications include pleural effusion, relapse of infection and spread of the infection throughout the body.
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Signs, symptoms & indicators of Valley Fever (Coccidioidomycosis):
Conditions that suggest Valley Fever (Coccidioidomycosis):
Risk factors for Valley Fever (Coccidioidomycosis):
Valley Fever (Coccidioidomycosis) can lead to:
KEY | | Weak or unproven link |  | | Strong or generally accepted link |  | | Proven definite or direct link |
GLOSSARY
Acute
An illness or symptom of sudden onset, which generally has a short duration.
AIDS
Acquired Immune Deficiency Syndrome. An immune system deficiency disorder that suddenly alters the body's ability to defend itself. The AIDS virus invades the T4 helper/inducer lymphocytes and multiplies, causing a breakdown in the body's immune system, eventually leading to overwhelming infection and/or cancer, with ultimate death.
Alkaline
A substance having a pH above that of neutral water (7.0) when in solution. Signified as pH (potential of Hydrogen), alkaline fluids, such as the blood (pH about 7.4), have the ability to neutralize acids (solutions below pH 7.0). Metabolic wastes are acids, and the alkaline reserve of the blood neutralizes them until they are excreted.
Antifungal (Antifungals)
An agent that kills or inhibits fungi, or a compound that inhibits either a dermatomycosis like ringworm or athlete's foot, or
one that inhibits Candida albicans either externally as a douche or internally as a systemic antifungal. Examples: Nystatin, griseofulvin, Tabebuia.
Arthritis (Arthritic)
Inflammation of a joint, usually accompanied by pain, swelling, and stiffness, and resulting from infection, trauma, degenerative changes, metabolic disturbances, or other causes. It occurs in various forms, such as bacterial arthritis, osteoarthritis, or rheumatoid arthritis. Osteoarthritis, the most common form, is characterized by a gradual loss of cartilage and often an overgrowth of bone at the joints.
Boil (Abscess, Abscesses, Boils, Carbuncle, Carbuncles, Furuncle, Furuncles, Cystic Acne, Hidradenitis Suppurativa, Pilonidal Cyst, Pilonidal Cysts)
A localized infection deep in the skin. A boil generally starts as a reddened, tender area. Over time, the area becomes firm and hard. Eventually, the center of the abscess softens and becomes filled with white cells that the body sends to fight the infection (pus). Finally, the pus forms a "head" and drains out through the skin. A furuncle or carbuncle is an abscess in the skin caused by the bacteria Staphylococcus aureus. It can have one or more openings onto the skin and may be associated with a fever or chills. Cystic acne is a type of abscess formed when oil ducts become clogged and infected. Cystic acne is most common in the teenage years. Hidradenitis suppurativa is an illness in which there are multiple abscesses that form under the arm pits and in the groin area. These areas are a result of local inflammation of the sweat glands. A pilonidal cyst is a special kind of abscess that occurs in the crease of the buttocks. These frequently form after long trips that involve sitting.
Bronchitis
Inflammation of the mucous membrane of the bronchial tubes, frequently accompanied by cough, hypersecretion of mucus, and expectoration of sputum. Acute bronchitis is usually caused by an infectious agent and of short duration. Chronic bronchitis, generally the result of smoking, may also be known as Chronic Obstructive Pulmonary Disease (COPD) or Emphysema.
Cellular Immunity
A branch of the immune system which involves direct attack by immune cells often called "T" cells. Antibodies play less of a role.
Central Nervous System (CNS)
A collective term for the brain, spinal cord, their nerves, and the sensory end organs. More broadly, this can even include the
neurotransmitting hormones instigated by the CNS that control the chemical nervous system, the endocrine glands.
Chronic (Chronicity)
Usually referring to chronic illness: Illness extending over a long period of time.
Coccidioidomycosis (Valley Fever)
A disease caused by inhaling spores of the fungus Coccidioides immitis. It starts out as a respiratory illness and may progress to a persistent infection; disseminated coccidioidomycosis is the most severe form and is often fatal. Anyone who is present near dust-producing activities where soil or other materials contaminated with C. immitis are present can get this disease if enough spores are inhaled. Symptoms: First the lungs are infected, possibly producing no symptoms at all or perhaps a fever, chills, and cough. This infection may heal completely, or result in other complications. Approximately 1-in-1000 cases will progress to the disseminated form, leading to 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).
Complete Blood Count (CBC)
A set of measurements that are generally determined by specially designed machines that analyze the different components of blood in less than a minute. The values generally included are:- White blood cell count (WBC). The number of white blood cells in a volume of blood. Normal range varies slightly between laboratories but is generally between 4,300 and 10,800 cells per cubic millimeter. This can also be referred to as the leukocyte count and can be expressed in international units as 4.3 - 10.8 x 10^9 cells per liter.
- Automated white cell differential. A machine-generated percentage of the different types of white blood cells, usually split into granulocytes, lymphocytes, monocytes, eosinophils, and basophils.
- Red cell count (RBC). The number of red blood cells in a volume of blood. Normal range varies slightly between laboratories but is generally between 4.2 - 5.9 million cells per cubic millimeter. This can also be referred to as the erythrocyte count and can be expressed in international units as 4.2 - 5.9 x 10^12 cells per liter.
- Hemoglobin (Hb). The amount of hemoglobin in a volume of blood. Normal range for hemoglobin is different between the sexes and is approximately 13 - 18 gm/dl for men and 12 - 16 for women (international units 8.1 - 11.2 millimoles/liter for men, 7.4 - 9.9 for women).
- Hematocrit (Hct). The ratio of the volume of red cells to the volume of whole blood. Normal range for hematocrit is different between the sexes and is approximately 45 - 52% for men and 37 - 48% for women.
- Mean cell volume (MCV). The average volume of a red cell. This is a calculated value derived from the hematocrit and red cell count. Normal range is 86 - 98 femtoliters.
- Mean cell hemoglobin (MCH). The average amount of hemoglobin in the average red cell. This is a calculated value derived from the measurement of hemoglobin and the red cell count. Normal range is 27 - 32 picograms.
- Mean cell hemoglobin concentration (MCHC). The average concentration of hemoglobin in a given volume of red cells. This is a calculated volume derived from the hemoglobin measurement and the hematocrit. Normal range is 32 - 36%.
- Red cell distribution width (RDW). A measurement of the variability of red cell size. Higher numbers indicate greater variation in size. Normal range is 11 - 15.
- Platelet count. The number of platelets in a volume blood. Platelets play a vital role in blood clotting. Normal range varies slightly between laboratories but is in the range of 150,000 - 400,000 per cubic millimeter (150 - 400 x 10^9 per liter).
Empyema
Pus located in a body cavity.
Endemic
Used to refer to a disease that constantly occurs in any particular geographical region.
Eosinophil (Eosinophilia, Eosinophils)
The eosinophils, ordinarily about 2% of the granulocyte count (60 to 75% of the white blood cells), increase in number in the presence of allergic disorders and parasitic infestations.
Erythema Nodosum
Acute inflammation of skin with red nodules.
Human Immunodeficiency Virus (HIV)
A retrovirus associated with onset of advanced immunodeficiency syndrome (AIDS).
Humoral Immunity
This refers to immunity to infection created by proteins termed antibodies, often referred to as "B" cells.
Immune System (Immune Response, Immunity)
A complex that protects the body from disease organisms and other foreign bodies. The system includes the humoral immune response and the cell-mediated response. The immune system also protects the body from invasion by making local barriers and inflammation. The process may involve acquired immunity (the ability to learn and remember a specific infectious agent), or innate immunity (the genetically programmed system of responses that attack, digest, remove, and initiate inflammation and tissue healing).
Kidneys (Kidney, Renal)
Bean-shaped organs, each about the size of a fist. They are located near the middle of the back, just below the rib cage. The kidneys are sophisticated reprocessing machines, each day handling about 50 gallons of blood to sift out about half a gallon of waste products and extra water. The waste and extra water become urine, which flows to the bladder through tubes called ureters. The actual filtering occurs in tiny units inside the kidneys called nephrons. Every kidney has about a million nephrons. In a nephron, a glomerulus -- which is a tiny blood vessel, or capillary -- intertwines with a tiny urine-collecting tube called a tubule. A complicated chemical exchange takes place, as waste materials and water leave your blood and enter your urinary system. The kidneys recycle chemicals such as sodium, phosphorus, and potassium and thus regulate their levels. Renal: Pertaining to the kidneys.
Lesion (Lesions)
Any damage to tissue structure or function; an abnormal change in body tissue caused by disease or injury. A scar is a lesion, as is cancer, a stomach ulcer or a pimple.
Liver (Hepatic)
The largest and one of the most complex organs of the body, the liver is responsible for much of the metabolism of fats, proteins and carbohydrates. It is the site of much of the body's detoxification. It is connected very closely with digestion and the regulation of blood sugar, among many other functions. Found behind the ribs on the right side of the abdomen, it has many important functions such as removing harmful material from the blood, making enzymes and bile that help digest food, and converting food into substances needed for life and growth. Hepatic: Pertaining to the liver.
Lung (Lungs, Pulmonary)
Organ of the body, located in the chest cavity which is designed to bring oxygen from the air into the blood stream, while also expelling carbon dioxide and other waste gases out of the body. Pulmonary: Related to the lungs.
Myalgia
Diffuse muscle pain.
Pneumonia (Pneumonitis)
Inflammation, usually infectious, of the lungs. Unless the result of only moderate chemical or smoke irritation, it is a potentially life-threatening condition. There are so many defenses against an infection this deep in the body that the very presence of pneumonia signals a pathogen of great virulence or impaired or exhausted immunity, or all three. Pneumonitis: Inflammation of the lungs, from whatever cause. It may be concurrent with pneumonia or pleurisy.
Pus
White cells that the body sends to fight an infection.
Serum
The cell-free fluid of the bloodstream. It appears in a test tube after the blood clots and is often used in expressions relating to the levels of certain compounds in the blood stream.
T-Cell (T-Cells)
T cells are lymphocytes that are produced in the bone marrow and mature in the thymus. T cells are responsible for mediating the second branch of the immune system called "cellular immune response." T cells can live for months to years. This lymphocyte population is defined by the presence of a rearranged T-cell receptor.
X-rays (X-ray)
High-energy radiation used to take pictures of areas inside the body.
Last updated: Oct 12, 2009
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