Coccidiomycosis

Coccidioidomycosis (/kɒkˌsɪdiɔɪdoʊmaɪˈkoʊsɪs/, kok-sid-ee-oy-doh-my-KOH-sis), commonly known as cocci, Valley fever, as well as California fever, desert rheumatism, and San Joaquin Valley fever, is a mammalian fungal disease caused by Coccidioides immitis or Coccidioides posadasii. Coccidioidomycosis is endemic in certain parts of the US in Arizona, California, Nevada, New Mexico, Texas, Utah, and northern Mexico. Coccidioidomycosis (/kɒkˌsɪdiɔɪdoʊmaɪˈkoʊsɪs/, kok-sid-ee-oy-doh-my-KOH-sis), commonly known as cocci, Valley fever, as well as California fever, desert rheumatism, and San Joaquin Valley fever, is a mammalian fungal disease caused by Coccidioides immitis or Coccidioides posadasii. Coccidioidomycosis is endemic in certain parts of the US in Arizona, California, Nevada, New Mexico, Texas, Utah, and northern Mexico. C. immitis is a dimorphic saprophytic fungus that grows as a mycelium in the soil and produces a spherule form in the host organism. It resides in the soil in certain parts of the southwestern United States, most notably in California and Arizona. It is also commonly found in northern Mexico, and parts of Central and South America. C. immitis is dormant during long dry spells, then develops as a mold with long filaments that break off into airborne spores when it rains. The spores, known as arthroconidia, are swept into the air by disruption of the soil, such as during construction, farming, or an earthquake. Windstorms may also cause epidemics far from endemic areas. In December 1977, a windstorm in an endemic area around Arvin, California led to several hundred cases, including deaths, in non-endemic areas hundreds of miles away. Coccidioidomycosis is a common cause of community-acquired pneumonia in the endemic areas of the United States. Infections usually occur due to inhalation of the arthroconidial spores after soil disruption. The disease is not contagious. In some cases the infection may recur or become chronic. An estimated 60% of people infected with the fungi responsible for coccidioidomycosis have minimal to no symptoms, while 40% will have a range of possible clinical symptoms. Of those who do develop symptoms, the primary infection is most often respiratory, with symptoms resembling bronchitis or pneumonia that resolve over a matter of a few weeks. In endemic regions, coccidioidomycosis is responsible for 20% of cases of community-acquired pneumonia. Notable coccidioidomycosis signs and symptoms include a profound feeling of tiredness, fever, cough, headaches, rash, muscle pain, and joint pain. Fatigue can persist for many months after initial infection. The classic triad of coccidioidomycosis known as 'desert rheumatism' includes the combination of fever, joint pains, and erythema nodosum. 3% to 5% of infected individuals do not recover from the initial acute infection and develop a chronic infection. This can take the form of chronic lung infection or widespread disseminated infection (affecting the tissues lining the brain, soft tissues, joints, and bone). Chronic infection is responsible for most of the morbidity and mortality. Chronic fibrocavitary disease is manifested by cough, sputum, fevers, night sweats and weight loss. Osteomyelitis, including involvement of the spine, and meningitis may occur months to years after initial infection. Severe lung disease may develop in HIV-infected persons. After Coccidioides infection, coccidioidomycosis begins with Valley fever, which is its initial acute form. Valley fever may progress to the chronic form and then to disseminated coccidioidomycosis. Therefore, Coccidioidomycosis may be divided into the following types: Serious complications may occur in patients who have weakened immune systems, including severe pneumonia with respiratory failure and bronchopleural fistulas requiring resection, lung nodules, and possible disseminated form, where the infection spreads throughout the body. The disseminated form of coccidioidomycosis can devastate the body, causing skin ulcers, abscesses, bone lesions, swollen joints with severe pain, heart inflammation, urinary tract problems, and inflammation of the brain's lining, which can lead to death. It must rain first to start the cycle of initial growth of the fungus underneath the soil. In soil (and in agar media), Coccidioides exist in filament form. It forms hyphae in both horizontal and vertical directions. Over a prolonged dry period, cells within hyphae degenerate to form alternating barrel-shaped cells (arthroconidia). Arthroconidia are light-weight and carried by air currents. This happens when the soil is disturbed often by clearing trees, construction and farming. As the population grows, so have all these industries, causing a potential cascade effect. The more land that is cleared, the more arid the soil, the riper the environment for Coccidioides. These spores can be easily inhaled without the person knowing. On arriving in alveoli, they enlarge in size to become spherules, and internal septations develop. This division of cells is made possible by the optimal temperature inside the body. Septations develop and form endospores within the spherule. Rupture of spherules release these endospores, which in turn repeat the cycle and spread the infection to adjacent tissues within the body of the infected individual. Nodules can form in lungs surrounding these spherules. When they rupture, they release their contents into bronchi, forming thin-walled cavities. These cavities can result in symptoms like characteristic chest pain, coughing up blood, and persistent cough. In individuals with a weakened immune system, the infection can spread through the blood. On rare occasion it can enter the body through a break in the skin, causing infection. Coccidioidomycosis diagnosis relies on a combination of an infected person's signs and symptoms, findings on radiographic imaging, and laboratory results. The disease is commonly misdiagnosed as bacterial community-acquired pneumonia. The fungal infection can be demonstrated by microscopic detection of diagnostic cells in body fluids, exudates, sputum and biopsy tissue by methods of Papanicolaou or Grocott's methenamine silver staining. These stains can demonstrate spherules and surrounding inflammation.