Coccidioidomycosis
Encyclopedia
Coccidioidomycosis is a fungal
disease caused by Coccidioides immitis
or C. posadasii
. It is endemic
in certain parts of Arizona
, California
, Nevada
, New Mexico
, Texas
, Utah
and northwestern Mexico
.
C. immitis resides in the soil
in certain parts of the southwestern United States
, northern Mexico, and parts of Central
and South America
. It is dormant during long dry spells, then develops as a mold with long filaments that break off into airborne spores when the rains come. The spores, known as arthroconidia, are swept into the air by disruption of the soil, such as during construction, farming, or an earthquake. Infection is caused by inhalation of the particles. The disease is not transmitted from person to person. C. immitis is a dimorphic saprophytic organism that grows as a mycelium
in the soil and produces a spherule form in the host organism.
, lung nodule
s, and disseminated disease, where the fungus spreads throughout the body. The disseminated form of valley fever can devastate the body, causing skin ulcers, abscess
es, bone lesions, severe joint pain, heart inflammation, urinary tract problems, meningitis
, and often death. In order of decreasing risk, people of Filipino, African, Native American, Hispanic, and Asian descent are susceptible to the disseminated form of the disease. Men and pregnant women, and people with weakened immune systems (as from AIDS
) are more susceptible than non-pregnant women.
It has been known to infect humans, cattle, deer, dogs, elk, fish, mules, livestock, apes, kangaroos, wallabies, tigers, bears, badgers, otters and marine mammals.
Symptomatic infection (40% of cases) usually presents as an influenza
-like illness with fever, cough, headaches, rash
, and myalgia
(muscle pain). Some patients fail to recover and develop chronic pulmonary infection or widespread disseminated infection (affecting meninges
, soft tissues, joints, and bone). Severe pulmonary disease may develop in HIV
-infected persons.
An additional risk is that health care providers who are unfamiliar with it or are unaware that the patient has been exposed to it may misdiagnose it as cancer
and subject the patient to unnecessary surgery
.
near Coalinga and Avenal State Prison
near Avenal on the western side of the San Joaquin Valley
had the highest incidence in 2005, of at least 3,000 per 100,000.
Incidence varies widely across the west and southwest. In Arizona, for instance, in 2007, there were 3,450 cases in Maricopa County, which in 2007 had an estimated population of 3,880,181 for an incidence of approximately 1 in 1,125. In contrast, though southern New Mexico is considered an endemic region, there were 35 cases in the entire state in 2008, and 23 in 2007, in a region that had an estimated 2008 population of 1,984,356 for an incidence of approximately 1 in 56,695. Infection rates vary greatly by county, and although population density is important, so are other factors that have not been proven yet. Greater construction activity may disturb spores in the soil. In addition, the effect of altitude on fungi growth and morphology has not been studied, and altitude can range from sea level to 10,000 feet or higher across California, Arizona, Texas and New Mexico.
In California from 2000 to 2007, there were 16,970 reported cases (5.9 per 100,000 people) and 752 deaths (0.26 per 100,000 people) with the highest incidence in the San Joaquin Valley (44.1 per 100,000).
s however.
and biopsy
-tissue. With specific nucleotide
primers C.immitis DNA
can be amplified by PCR
. It can also be detected in culture by morphological identification or by using molecular probes that hybridize with C.immitis RNA
. An indirect demonstration of fungal infection can be achieved also by serologic analysis detecting fungal antigen
or host antibody
produced against the fungus.
and intravenous
Amphotericin B
are used in progressive or disseminated disease, or in which patients are immunocompromised. Alternatively, itraconazole
or ketoconazole
may be used. Posaconazole and voriconazole have also been used.
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
disease caused by Coccidioides immitis
Coccidioides immitis
Coccidioides immitis is a pathogenic fungus that resides in the soil in certain parts of the southwestern United States, northern Mexico, and a few other areas in the Western Hemisphere....
or C. posadasii
Coccidioides posadasii
Coccidioides posadasii is a pathogenic fungus that, along with Coccidioides immitis, is the causative agent of coccidioidomycosis in humans. It resides in the soil in certain parts of the Southwestern United States, northern Mexico, and certain other areas in the Americas.C. posadasii and C...
. It is endemic
Endemic (epidemiology)
In epidemiology, an infection is said to be endemic in a population when that infection is maintained in the population without the need for external inputs. For example, chickenpox is endemic in the UK, but malaria is not...
in certain parts of Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
, New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
, Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
, Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
and northwestern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
.
C. immitis resides in the soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
in certain parts of the southwestern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, northern Mexico, and parts of Central
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. It is dormant during long dry spells, then develops as a mold with long filaments that break off into airborne spores when the rains come. The spores, known as arthroconidia, are swept into the air by disruption of the soil, such as during construction, farming, or an earthquake. Infection is caused by inhalation of the particles. The disease is not transmitted from person to person. C. immitis is a dimorphic saprophytic organism that grows as a mycelium
Mycelium
thumb|right|Fungal myceliaMycelium is the vegetative part of a fungus, consisting of a mass of branching, thread-like hyphae. The mass of hyphae is sometimes called shiro, especially within the fairy ring fungi. Fungal colonies composed of mycelia are found in soil and on or within many other...
in the soil and produces a spherule form in the host organism.
Presentation
The disease is usually mild, with flu-like symptoms and rashes. The Mayo Clinic estimates that half the population in some affected areas have suffered from the disease. On occasion, those particularly susceptible may develop a serious or even fatal illness. Serious complications include severe pneumoniaPneumonia
Pneumonia is an inflammatory condition of the lung—especially affecting the microscopic air sacs —associated with fever, chest symptoms, and a lack of air space on a chest X-ray. Pneumonia is typically caused by an infection but there are a number of other causes...
, lung nodule
Nodule (medicine)
For use of the term nodule in dermatology, see Nodule In medicine, a nodule refers to a relatively hard, roughly spherical abnormal structure....
s, and disseminated disease, where the fungus spreads throughout the body. The disseminated form of valley fever can devastate the body, causing skin ulcers, abscess
Abscess
An abscess is a collection of pus that has accumulated in a cavity formed by the tissue in which the pus resides due to an infectious process or other foreign materials...
es, bone lesions, severe joint pain, heart inflammation, urinary tract problems, meningitis
Meningitis
Meningitis is inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs...
, and often death. In order of decreasing risk, people of Filipino, African, Native American, Hispanic, and Asian descent are susceptible to the disseminated form of the disease. Men and pregnant women, and people with weakened immune systems (as from AIDS
AIDS
Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...
) are more susceptible than non-pregnant women.
It has been known to infect humans, cattle, deer, dogs, elk, fish, mules, livestock, apes, kangaroos, wallabies, tigers, bears, badgers, otters and marine mammals.
Symptomatic infection (40% of cases) usually presents as an influenza
Influenza
Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae , that affects birds and mammals...
-like illness with fever, cough, headaches, rash
Rash
A rash is a change of the skin which affects its color, appearance or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracked or blistered, swell and may be painful. The causes, and...
, and myalgia
Myalgia
Myalgia means "muscle pain" and is a symptom of many diseases and disorders. The most common causes are the overuse or over-stretching of a muscle or group of muscles. Myalgia without a traumatic history is often due to viral infections...
(muscle pain). Some patients fail to recover and develop chronic pulmonary infection or widespread disseminated infection (affecting meninges
Meninges
The meninges is the system of membranes which envelopes the central nervous system. The meninges consist of three layers: the dura mater, the arachnoid mater, and the pia mater. The primary function of the meninges and of the cerebrospinal fluid is to protect the central nervous system.-Dura...
, soft tissues, joints, and bone). Severe pulmonary disease may develop in HIV
HIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
-infected persons.
An additional risk is that health care providers who are unfamiliar with it or are unaware that the patient has been exposed to it may misdiagnose it as cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
and subject the patient to unnecessary surgery
Surgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
.
Types
Coccidioidomycosis may be divided into the following types:- Primary pulmonary coccidioidomycosisPrimary pulmonary coccidioidomycosisPrimary pulmonary coccidioidomycosis is an infection caused by inhalation of Coccidioides immitis. Once pulmonary symptoms subside, about 30% of women and 15% of men will have allergic skin manifestations in the form of erythema nodosum...
- Disseminated coccidioidomycosisDisseminated coccidioidomycosisDisseminated coccidioidomycosis is a systemic infection with Coccidioides immitis, in which 15-20% of people develop skin lesions....
- Primary cutaneous coccidioidomycosisPrimary cutaneous coccidioidomycosisPrimary cutaneous coccidioidomycosis is a skin condition cause by Coccidioides immitis following a definite history of inoculation or a colonized splinter is found in the skin lesion....
Incidence (North America)
California state prisons, as far back as 1919, have been particularly affected by Coccidioidomycosis. In 2005 and 2006, the Pleasant Valley State PrisonPleasant Valley State Prison
Pleasant Valley State Prison is a minimum/medium/maximum security state prison in Coalinga, Fresno County, California. The facility houses Sirhan Sirhan, the convicted assassin of Senator Robert F...
near Coalinga and Avenal State Prison
Avenal State Prison
Avenal State Prison is a male-only state prison in the city of Avenal, Kings County, California.-Facilities:The structures on ASP's include "17 open dorm buildings, six 200-bed open dorm E-bed buildings, six converted gymnasiums, a 100-cell administrative segregation unit, and a 10-bed...
near Avenal on the western side of the San Joaquin Valley
San Joaquin Valley
The San Joaquin Valley is the area of the Central Valley of California that lies south of the Sacramento – San Joaquin River Delta in Stockton...
had the highest incidence in 2005, of at least 3,000 per 100,000.
Incidence varies widely across the west and southwest. In Arizona, for instance, in 2007, there were 3,450 cases in Maricopa County, which in 2007 had an estimated population of 3,880,181 for an incidence of approximately 1 in 1,125. In contrast, though southern New Mexico is considered an endemic region, there were 35 cases in the entire state in 2008, and 23 in 2007, in a region that had an estimated 2008 population of 1,984,356 for an incidence of approximately 1 in 56,695. Infection rates vary greatly by county, and although population density is important, so are other factors that have not been proven yet. Greater construction activity may disturb spores in the soil. In addition, the effect of altitude on fungi growth and morphology has not been studied, and altitude can range from sea level to 10,000 feet or higher across California, Arizona, Texas and New Mexico.
In California from 2000 to 2007, there were 16,970 reported cases (5.9 per 100,000 people) and 752 deaths (0.26 per 100,000 people) with the highest incidence in the San Joaquin Valley (44.1 per 100,000).
Biological warfare
C. immitis was investigated by the United States during the 1950s and 1960s as a potential biological weapon. The Cash strain received the military symbol OC, and original hopes were for its use as an incapacitant. As medical epidemiology later made clear, OC would have lethal effects on several segments of the population, so it was later considered a lethal agent. It was never standardized, and beyond a few field trials, it was never weaponized. Most military work on OC was on vaccines by the mid-1960s. It is still on the CDC's list of select agentSelect agent
In United States law, Select Agents are pathogens or biological toxins which have been declared by the U.S. Department of Health and Human Services or by the U.S. Department of Agriculture to have the "potential to pose a severe threat to public health and safety"...
s however.
Diagnostic test
The fungal infection can be demonstrated by microscopic detection of diagnostic cells in body fluids, exudates, sputumSputum
Sputum is mucus that is coughed up from the lower airways. It is usually used for microbiological investigations of respiratory infections....
and biopsy
Biopsy
A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...
-tissue. With specific nucleotide
Nucleotide
Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...
primers C.immitis DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
can be amplified by PCR
Polymerase chain reaction
The polymerase chain reaction is a scientific technique in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence....
. It can also be detected in culture by morphological identification or by using molecular probes that hybridize with C.immitis RNA
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
. An indirect demonstration of fungal infection can be achieved also by serologic analysis detecting fungal antigen
Antigen
An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...
or host antibody
Antibody
An antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...
produced against the fungus.
Treatment
There are no published prospective studies that examine optimal antifungal therapy for coccidioidomycosis. Mild cases often do not require treatment. Oral FluconazoleFluconazole
Fluconazole is a triazole antifungal drug used in the treatment and prevention of superficial and systemic fungal infections. In a bulk powder form, it appears as a white crystalline powder, and it is very slightly soluble in water and soluble in alcohol. It is commonly marketed under the trade...
and intravenous
Intravenous therapy
Intravenous therapy or IV therapy is the infusion of liquid substances directly into a vein. The word intravenous simply means "within a vein". Therapies administered intravenously are often called specialty pharmaceuticals...
Amphotericin B
Amphotericin B
Amphotericin B is a polyene antifungal drug, often used intravenously for systemic fungal infections...
are used in progressive or disseminated disease, or in which patients are immunocompromised. Alternatively, itraconazole
Itraconazole
Itraconazole , invented in 1984, is a triazole antifungal agent that is prescribed to patients with fungal infections. The drug may be given orally or intravenously.-Medical uses:...
or ketoconazole
Ketoconazole
Ketoconazole is a synthetic antifungal drug used to prevent and treat fungal skin infections, especially in immunocompromised patients such as those with AIDS or those on chemotherapy. Ketoconazole is sold commercially as an anti-dandruff shampoo, topical cream, and oral tablet.Ketoconazole is...
may be used. Posaconazole and voriconazole have also been used.