Valley Fever Essay
In the Northern hemisphere, particularly in southwestern regions, the United States and in northern Mexico dwells a disease called Coccidioidomycosis, which is also known as San Joaquin Fever, Valley Fever and Posada’s disease. Coccidioidomycosis is a fungal disease, which in most cases enters the body through the lungs. Both humans and mammals are susceptible to this infection. Specific areas have become endemic for a variety of reasons. Some reasons being, population swelling and the increase in tourism, that causes the infection to grow and manifest itself. There are various forms, where the infection can occur, such as: chronic progressive pneumonia, acute pneumonia, meningitis and extra pulmonary non-meningeal disease.
The infection does not affect everyone the same and can cause only flu-like symptoms for patients, while others can experience the more severe side. This specific fungal infection has no exact cure but does have a handful of treatments available. A medical student in Argentina, Alejandro Posadas, discovered the first case of Coccidioidomycosis in 1892. Alejandro was an intern in Buenos Aires was studying a soldier who had a lesion on his right cheek. Later on more red and itchy spots developed and evolved into papules that discharged pus, another sign of the disease. By 1894 reports started to surface of Coccidioidomycosis, in California.
Up until 1929 the infection was looked upon as being rare and fatal, but in the 1930’s and 40’s this view changed. The idea of it being less fatal steamed from the accidental inhaling of a specimen culture done by a medical student. In the end it turned out to be the nonfatal form of the infection, which led to the creation of skin tests and serological testing. Many immigrants were also moving from the Midwest to San Joaquin Valley, California to avoid drought and find employment, adding to the population growth.
Also, during the years of World War II military workers who were practicing dessert combat and doing construction outdoors had come down with “valley fever” which caused multiple important studies to be conducted. The interest of studying Coccidioidomycosis has been renewed over the years because of the increase of migration to the Sunbelt states. Places like; Tuscon, Arizona; Fresno and Bakersfield Fresno, California and Texas were once populated with just a few people have now become these large cities. Large cities mean a higher population, which means a higher risk for the disease. There are two specific fungi’s that when combined cause the infection Coccidioidomycosis. These funguses are called, Coccidioides immitis and Coccidioides posadasii.
Coccidioides immitis and C possadasii are both pathogenic fungus that are dimorphic, meaning they can live in either yeast or a mold and they are both soil- borne. These fungi’s share multiple characteristics but their tolerance to salt and heat differ. Both of them can be found in semiarid regions that have alkaline sandy soils. Once the funguses grow they absorb different decaying materials, and turn into a mold, which forms a spore. Spores are tiny temporary inactive forms of a germ enclosed in a protective shell. When both of the above fungi’s do combine they cause the “valley fever” infection. The C immitis species exists in both saprophytic and parasitic phases. Saprophytic is the nourishment the funguses take in from decaying or dead organic materials.
The parasitic phase is when the host inhales the toxic spores. Both funguses may look the same but differ in terms of each ones’ tolerance to heat and saline levels. Once the microscopic spores enter the lungs the change in temperature occurs. Once that happens the fungus takes on a new form called a spherule in the tissue. On other occasions these spores can enter the body through cuts or abrasions on the surface of ones skin, leading to infection. The incubation period of the infection is anywhere from 1 to 4 weeks. A large percentage of people who become infected are asymptomatic, showing no signs of the infection.
The other people who are symptomatic will at some point show influenza like symptoms such as, a fever, headache, muscle aches, and weight loss and in some cases pneumonia. There are rare instances where severe lung disease or spreading of the infection to the central nervous system, bones and skin can further develop The dissemination, how the fungal disease Coccidioidomycosis can spread is triggered by a number of various factors. Natural energies such as wind, earthquake’s or any type of disruption to the surface of the soil can cause the spores to become released into the atmosphere. Humans can also cause the infection through their everyday activities like landscaping, construction and some recreational hobbies like dirt biking.
The endemic places where these alkaline soils are found are in the Southwestern United States, Northern parts of Mexico and different spots in Central America and South America. The disease is highly infectious in the discussed regions, but because of increasing travel and population mobility it has spread outside its original regions. Once the disturbance occurs in the contaminated soil/dirt the spores become airborne. This is the infectious phase because they can easily be inhaled without realizing. Not everybody is equally susceptible to the disease, but it can happen at any age.
The People that are at higher risk of developing the much more severe cases are; the elderly, African-Americans, Asian or Filipinos, persons with immune compromising conditions like HIV cancer, organ transplant patients because of the immunosuppressive regime. Also in women who are in their third trimester because of their shifts in T-cell immunity, hormone changes. Elderly patients are another group who are at a high risk; ages not being the only factor but their immune systems are just not as strong as they once were. The mortality rate of 65 year old patients and up experience a 15% increase. Some of the more dangerous distributions of the infection can lead to lung abscesses, scarring of the lung or collections of pus in the lung.
Once a person becomes infected with Coccidioides they are immune to reinfection. However, the people who have never been infected by it before that are a higher risk to become infected as well as a higher risk of experiencing the more severe side of the spectrum of symptoms. Luckily, Coccidioidomycosis is not a person-to-person disease and animals can also develop it, but they cannot transmit it to other animals or human beings. In terms of the ecological and evolutionary model surrounding Coccidioidomycosis, there are a multitude of similarities between a society and its adaptions to the environment. The aspects of the disease in relation to the environment play a big role. Just looking at the environment alone the temperature, the amount of precipitation, the levels of sun exposure and the characteristics of the soil play major roles in this infection.
The disease is most common during dry, dusty periods when the fungus can become airborne. The seasons also plays a key role, the highest prevalence of the infection happens during the month of June until July and from October until November. Once people inhabit these specific regions, they become another key factor in the infection. Valley Fever outbreaks have occurred because of the influential relationship between the infection itself and the changing climate conditions. For example in December of 1977, a dust storm blew through Kern County, California and brought with it C. immitis spores. Spreading it into the north and west, which sparked an epidemic, creating the highest number ever recorded in California before that year.
Thankfully, rain followed that week and helped prevent the epidemic from worsening. Studies have also shown that the larger majority of the people who inhabit these environments about 60% of them are infected, but only some show mild symptoms or none at all. One in 1,000 people with Coccidioidomycosis will develop the more widespread infection. Another fact about these known endemic areas is that they are not the only places that the infection will remain in. Travelers have played a role in spreading the disease from place to place. There have been frequent reports in the past of Coccidioidomycosis cases popping up in non- endemic areas. Places such as Colorado, Missouri, Maryland, Louisiana, New Hampshire and Delaware.
When it comes to treating the infection, doctors have to first diagnosis it properly. There are also three risk factors that must be taken into consideration, those being; severity of the pulmonary infection, patient’s individual risk factors and the presence of the disseminated disease. The less severe cases use tests like the Sputum smear test, or culture, which is when a sample of what the patient coughs up is collected and sent out. The other tests that can be used are blood tests, which will detect the antibodies against the fungus or the other being a simple chest x-ray. Some patients after being diagnosed may not need treatment at all, just plenty of rest and liquids. Doctors will give them the same recommendations that a person with the flu or common cold would do.
For the more severe cases of valley fever there is a set of other tests. For the other widespread cases doctors may do a biopsy of the marrow, lymph nodes, lung or liver. Another way is by doing a spinal tap, which is a lumbar puncture, which will help rule out meningitis. These higher risk patients have a greater chance of experiencing complications; therefore will be administered antifungal medications, fluconazole and itraconazole. In very rare cases surgery is sometimes necessary, if there is a need to remove an infected portion of the lung. The first effective therapy for the disease was intravenous, in 1957. In the 1980’ s many oral antifungal agents that were created help lead to the development of many possible treatments.
As far as over the counter treatments go there are none, even to this day. A susceptible group is travelers; even though there is no vaccine available for Coccidioidomycosis they can still decrease their chances of contracting the infection. They can either limiting their outdoor exposure, as well as taking prophylactic-anti-fungal medication, from doctors. Vulnerable groups are advised to clean any cuts or scraps with soap and water to help keep away infections. Wetting the soil is another form of controlling the dusts disruption levels. Dust masks can also be worn to filter out tiny particles, as well as traveling in enclosed airtight air-conditioned vehicles. However, in the non-endemic areas people are advised to not work in dusty occupations and to have skin tests done of the individuals whoa re more susceptible.
Today Coccidioidomycosis is reportable; physicians must report cases to the health authorities. In the United States there are also 150,000 new cases reported per year. In 2010 over 16,000 cases of Coccidioidomycosis were reported, the majority of them being in Arizona and California. Health officials are not 100% sure as to why but believe that it has to do with the drought, construction work increase and the constant new comers. Outbreaks still occur, usually after specific events that cause large disturbances in the soil.
Relapses of the infection in former patients is possible and has been estimated in 30% or less of individuals. However with the right monitoring and continuation of antifungal medication during the first infection they can reduce their risk of relapsing. The outlook for recovering is usually a good one, unless you have a compromised immune system. Public health agencies have also been funding research studies and working towards the creation of a vaccine for Coccidioidomycosis.
Coccidioidomycosis or otherwise known as Valley fever is a fungal infection that is caused by two dimorphic funguses. The disease can occur in various formations: acute pneumonia, pulmonary nodules, meningitis, and non-meningeal disease. The endemic areas that are greatly affected by this disease are parts of southwestern United States and parts of Mexico, Central American and South America. The infection does not affect everyone in the same way, but can be dangerous for people who already have immune compromising diseases. In todays society this fungal infection it is still an existing issue. However, because of multiple studies that are since ongoing since its origination there are now more treatments available and the possibility of a vaccine in the near future.
* Hirschmann, J. V. (2007). The early history of coccidioidomycosis: 1892-1945. * n.p. (2010, May 21). “What Is Valley Fever (Coccidioidomycosis)? What Causes Valley Fever?.” Medical News Today. Retrieved from * http://www.medicalnewstoday.com/articles/189430.php.
* Ampel NM. Coccidioidomycosis: a review of recent advances. Clin Chest Med. 2009 Jun;30(2):241–51. * Galgiani JN. Coccidioidomycosis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 341. * Hector RF, Laniado-Laborin R (2005) Coccidioidomycosis—A Fungal Disease of the Americas. PLoS Med 2(1): e2. doi:10.1371/journal.pmed.0020002
Subject: Immune system,
University/College: University of Arkansas System
Type of paper: Thesis/Dissertation Chapter
Date: 16 February 2017
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