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Blastomycosis

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Description: Blastomycosis is a fungal infection caused by inhaling spores of the Blastomyces species, primarily affecting the lungs but potentially spreading to other organs.
Type: Blastomycosis is a fungal infection caused by the organism Blastomyces dermatitidis. It is not a genetic disorder and therefore does not involve genetic transmission. Instead, it is typically acquired by inhaling spores from the environment, particularly in areas with moist soil and decomposing organic matter.
Signs And Symptoms: The symptoms of blastomycosis cover a wide range, overlapping with more common conditions; for this reason, blastomycosis has often been called "the great pretender". Many cases are asymptomatic or subclinical. Lung symptoms are common, because the lungs are infected in 79% of blastomycosis cases. However, in 25-40% of cases the disease also disseminates to other organs, including the skin.The extent and severity of symptoms depends in part on a person's immune status; less than 50% of healthy people with blastomycosis have symptoms, while immunocompromised patients are especially likely to have the disease spread beyond the lungs to other organs like the skin and bones.Blastomycosis manifests as a primary lung infection in about 79% of cases. The onset is relatively slow and symptoms are suggestive of bacterial pneumonia, often leading to initial treatment with antibacterials. Because the symptoms are variable and nonspecific, blastomycosis is often not even considered in differential diagnosis until antibacterial treatment has failed, unless there are known risk factors or skin lesions. The disease may be misdiagnosed as a carcinoma, leading in some cases to surgical removal of the affected tissue. Upper lung lobes are involved somewhat more frequently than lower lobes. If untreated, many cases progress over a period of months to years to become disseminated blastomycosis.
Blastomycosis in the lungs may present a variety of symptoms, or no symptoms at all. If symptoms are present they may range from mild pneumonia resembling a pneumococcal infection to acute respiratory distress syndrome (ARDS). Common symptoms include fever, chills, headache, coughing, difficulty breathing, chest pain, and malaise. Without treatment, cases may progress to chronic pneumonia or ARDS.ARDS is an uncommon but dangerous manifestation of blastomycosis. It was seen in 9 of 72 blastomycosis cases studied in northeast Tennessee. Such cases may follow massive exposure, such during brush clearing operations. In the Tennessee study, the fatality rate was 89% in the ARDS cases, but only 10% in the non-ARDS cases.In disseminated blastomycosis, the large Blastomyces yeast cells translocate from the lungs and are trapped in capillary beds elsewhere in the body, where they cause lesions. The skin is the most common organ affected, being the site of lesions in approximately 60% of cases. The signature image of blastomycosis in textbooks is the indolent, verrucous or ulcerated dermal lesion seen in disseminated disease. Osteomyelitis is also common (12–60% of cases). Other recurring sites of dissemination are the genitourinary tract (kidney, prostate, epididymis; collectively ca. 25% of cases) and the brain (3–10% of cases). 40% of immunocompromised individuals have CNS involvement and present as brain abscess, epidural abscess or meningitis.
Blastomycosis in non-lung organs such as the skin may present a very wide range of symptoms, including the following:

skin lesions, which may be verrucous (wart-like) or ulcerated with small pustules at the margins.
bone or joint pain due to bone lytic lesions.
pain when urinating due to prostatitis.
hoarseness due to laryngeal involvement.
headache, confusion or other neurological symptoms caused by central nervous system involvement.
Prognosis: Published estimates of the case fatality rate for blastomycosis have varied from 4% to 78%. A 2020 meta-analysis of published studies found an overall mortality rate of 6.6%. This rose to 37% for immunocompromised patients and 75% for patients with ARDS. A 2021 analysis of 20 years of disease surveillance data from the five US states where blastomycosis is reportable found an overall mortality rate of 8% and a hospitalization rate of 57%. These numbers may be affected by the under-reporting of mild cases.
Onset: Blastomycosis is a fungal infection caused by the organism *Blastomyces dermatitidis*. The onset of symptoms typically occurs between 3 to 15 weeks after exposure to the fungus. Common symptoms include fever, cough, night sweats, muscle aches, weight loss, chest pain, and fatigue. In some cases, the fungus can disseminate to other parts of the body, causing skin lesions, bone pain, or central nervous system involvement.
Prevalence: Blastomycosis is relatively rare, with its prevalence difficult to generalize due to variability by geographic region. It is most commonly reported in North America, particularly in areas surrounding the Great Lakes, the Ohio River Valley, and the Mississippi River Valley. Exact prevalence rates can vary, but it is often considered an uncommon infection overall.
Epidemiology: Incidence in most endemic areas is about 0.5 per 100,000 population, with occasional local areas attaining as high as 12 per 100,000. Most Canadian data fit this picture. In Ontario, Canada, considering both endemic and non-endemic areas, the overall incidence is around 0.3 cases per 100,000; northern Ontario, mostly endemic, has 2.44 per 100,000. Manitoba is calculated at 0.62 cases per 100,000. Remarkably higher incidence was shown for the Kenora, Ontario region: 117 per 100,000 overall, with aboriginal reserve communities experiencing 404.9 per 100,000. In the United States, the incidence of blastomycosis is similarly high in hyperendemic areas. For example, the city of Eagle River, Vilas County, Wisconsin, which has an incidence rate of 101.3 per 100,000; the county as a whole has been shown in two successive studies to have an incidence of about 40 cases per 100,000. An incidence of 277 per 100,000 was roughly calculated based on 9 cases seen in a Wisconsin aboriginal reservation during a time in which extensive excavation was done for new housing construction. The new case rates are greater in northern states such as Wisconsin, where from 1986 to 1995 there were 1.4 cases per 100,000 people.The study of outbreaks as well as trends in individual cases of blastomycosis has clarified a number of important matters. Some of these relate to the ongoing effort to understand the source of infectious inoculum of this species, while others relate to which groups of people are especially likely to become infected. Human blastomycosis is primarily associated with forested areas and open watersheds; It primarily affects otherwise healthy, vigorous people, mostly middle-aged, who acquire the disease while working or undertaking recreational activities in sites conventionally considered clean, healthy and in many cases beautiful. Repeatedly associated activities include hunting, especially raccoon hunting, where accompanying dogs also tend to be affected, as well as working with wood or plant material in forested or riparian areas, involvement in forestry in highly endemic areas, excavation, fishing and possibly gardening and trapping.
Intractability: Blastomycosis is not considered intractable. It is a fungal infection typically treatable with antifungal medications such as itraconazole or amphotericin B. Early diagnosis and appropriate treatment usually lead to a good prognosis. However, severe cases or delayed treatment can complicate management.
Disease Severity: Disease Severity: Moderate to severe, can vary from mild flu-like symptoms to severe pulmonary or disseminated disease affecting multiple organ systems. Severe cases may require antifungal treatment and hospitalization.

Nan: Blastomycosis is caused by the inhalation of the fungal spores *Blastomyces dermatitidis* or *Blastomyces gilchristii*.
Healthcare Professionals: Disease Ontology ID - DOID:12663
Pathophysiology: Blastomycosis is a fungal infection caused by the dimorphic fungus *Blastomyces dermatitidis*. The pathophysiology involves the following stages:

1. **Inhalation**: Spores from *Blastomyces dermatitidis* are inhaled from disturbed soil or decaying organic matter.
2. **Lung Infection**: Once inhaled, the spores transform into yeast form within the lungs.
3. **Immune Response**: The body’s immune system responds to the infection, often leading to either clearance of the pathogen or containment within granulomas.
4. **Dissemination**: In some cases, the yeast can disseminate from the lungs to other parts of the body through the bloodstream or lymphatic system, affecting skin, bones, and other organs.

This infection can manifest as a mild respiratory illness, but in severe cases, it can lead to a chronic, disseminated infection affecting multiple organs.
Carrier Status: Blastomycosis is not typically associated with a carrier status because it is a fungal infection. It is caused by inhaling spores of the fungus Blastomyces dermatitidis, and it does not have an asymptomatic carrier state in humans.
Mechanism: Blastomycosis is a fungal infection caused by the organism *Blastomyces dermatitidis*.

**Mechanism:**
The primary mechanism involves the inhalation of airborne spores (conidia) from the environment, particularly in areas with moist soil and decaying organic matter. Once inhaled, the spores reach the lungs and convert into yeast form at body temperature. This yeast form is more resistant to immune defenses and can disseminate through the bloodstream to other organs such as the skin, bones, and central nervous system.

**Molecular mechanisms:**
1. **Thermotolerance and Morphological Transition**: *Blastomyces dermatitidis* undergoes a temperature-induced morphological shift from mold with conidia at environmental temperatures to yeast in the human host. Specific temperature-responsive genes regulate this transition.

2. **Virulence Factors**:
- **BAD1 Protein**: This adhesion molecule plays a crucial role in immune evasion and tissue colonization. It facilitates adherence to host tissues and suppresses the production of TNF-alpha, an important cytokine in the host’s immune response.
- **HSP60**: Heat shock proteins like HSP60 help the fungus survive in hostile environments within the host by refolding damaged proteins and aiding in stress response.

3. **Immune Evasion**: The yeast form produces a thick cell wall rich in polysaccharides, particularly glucans, which can modulate immune response and protect the fungus from phagocytosis by macrophages.

Understanding these molecular mechanisms helps in the development of targeted therapies and diagnostic tools for blastomycosis.
Treatment: Under Infectious Disease Society of America guidelines, severe cases of blastomycosis and cases with central nervous system (CNS) involvement are treated initially with amphotericin B, followed by a lengthy course of an azole drug such as itraconazole. In most cases the amphotericin treatment lasts for 1–2 weeks, but in cases of CNS involvement it may last for up to 6 weeks. Cases that do not require amphotericin B treatment are treated with a lengthy course of an azole drug.Among azole drugs, itraconazole is generally the treatment of choice. Voriconazole is often recommended for CNS blastomycosis cases due to its ability to pass the blood–brain barrier. Other azole drugs that may be used include fluconazole. Ketoconazole was the azole drug first used for blastomycosis treatment, but has been largely replaced by itraconazole because ketoconazole is less effective and less tolerated by patients. The azole treatment generally lasts for a minimum of six months. Cure rates from itraconazole treatment are nearly 95%. Relapse is rare but does occur even after a full course of treatment.
Compassionate Use Treatment: For blastomycosis, compassionate use treatments and off-label or experimental treatments might be considered when standard therapies are ineffective or unavailable.

1. **Compassionate Use Treatment**: This involves the use of investigational drugs for patients with serious or life-threatening conditions when no comparable or satisfactory alternative treatments exist. Specific details about compassionate use for blastomycosis should be obtained from healthcare providers or clinical trial coordinators as they vary on a case-by-case basis.

2. **Off-label Treatments**: Amphotericin B and itraconazole are the first-line treatments for blastomycosis. Sometimes, other antifungal medications like fluconazole can be used off-label depending on the patient's condition and physician's judgment.

3. **Experimental Treatments**: Participation in clinical trials could provide access to novel treatments or regimens being studied. Patients interested in experimental options should consult with their healthcare providers or clinical trial registries for the latest research developments and eligibility criteria.

Always consult healthcare professionals for personalized medical advice and treatment options.
Lifestyle Recommendations: For managing and preventing blastomycosis, consider these lifestyle recommendations:

1. **Limit Exposure to Endemic Areas**: Avoid activities that disrupt soil in regions where Blastomyces fungi are common, such as the Ohio and Mississippi River valleys, the Great Lakes, and parts of Canada.

2. **Protective Gear**: Wear masks and protective clothing when engaging in outdoor activities that may disturb soil, such as farming, gardening, or construction.

3. **Indoor Air Quality**: Ensure good ventilation and air filtration in homes and workplaces, especially if you live in an endemic area.

4. **Skin Protection**: Use protective measures to prevent skin injuries that could potentially be exposed to soil or decaying wood.

5. **Monitor Health**: If you develop symptoms like persistent cough, fever, or chest pain after exposure to areas known for Blastomyces, seek medical attention promptly.

6. **Pet Care**: Protect pets from exposure to soil in endemic areas, as they can also be at risk of contracting blastomycosis.

By following these recommendations, you can reduce the risk of contracting blastomycosis.
Medication: Blastomycosis is treated primarily with antifungal medications. The first-line treatment is usually itraconazole for mild to moderate cases. For severe cases or immunocompromised patients, amphotericin B is often used. Fluconazole can be an alternative in some instances, although it is generally less effective.
Repurposable Drugs: Repurposable drugs for blastomycosis may include itraconazole, which is often the first-line treatment. Amphotericin B can be used, especially in severe cases. Fluconazole is another antifungal that might be considered, although itraconazole is generally preferred due to better efficacy against Blastomyces dermatitidis.
Metabolites: Blastomycosis is a fungal infection caused by *Blastomyces dermatitidis*. The major metabolites identified in the pathogenesis and diagnostic context include ergosterol, a key component of the fungal cell membrane, and β-glucans, which are polysaccharides found in the fungal cell wall. Detection of these metabolites can aid in the diagnosis and monitoring of the infection.
Nutraceuticals: There is no substantial scientific evidence supporting the use of nutraceuticals for the prevention or treatment of blastomycosis. Blastomycosis is a fungal infection caused by the Blastomyces species, and it is typically treated with antifungal medications such as itraconazole or amphotericin B. Consult a healthcare professional for proper diagnosis and treatment.
Peptides: Blastomycosis is a fungal infection caused by the organism Blastomyces dermatitidis. It typically affects the lungs but can also spread to other parts of the body. There is limited specific information available about peptides or nano-scale treatments (nan) directly related to blastomycosis. Current treatments primarily involve antifungal medications like itraconazole or amphotericin B. Researchers are continually exploring advanced therapeutic options, including potential peptide-based and nanotechnology-driven solutions, but these are not yet standard practice for blastomycosis.