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Histoplasmosis:essential data |
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Fungal weapon acting on humans |
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Synopsis, Diagnosis, Symptoms,
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Safety Precautions for Histoplasmosis Casualties |
Standard Precautions defined by the 1996 CDC guidelines should be adopted for handling patients.Biosafety level 3 practices should be adopted for handling of samples. |
| Causative organism: (Systematic name in 1997) | Histoplasma capsulatum, Histoplasma capsulata duboisii |
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| Alternative Disease Names: |
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| Taxonomy: | Histoplasma capsulatum is a dimorphic fungus, living as a filamentous fungus in soil or as a yeast in its animal host, belonging to the Ascomycetes. |
| Vector Involvement: | None. |
| Epidemiology of natural outbreaks: | Spores of the fungus are widespread in soil in the United States. Infection typically comes in clusters as a result of disturbing a spore-rich soil. Outbreaks have been seen after earthquakes in California as spores are thrown into the air by the violent movement of the earth. |
The disease presents itself in many ways. The commonest route of infection is by inhalation and the commonest presentation is as a mild respiratory illness similar to a cold or influenza. Typical symptoms include fever, malaise, headache, myalgia, anorexia, cough, chest pain, anemia, leukopenia, thrombocytopenia and ulceration of the mouth and throat Even then, the primary infection may be asymptomatic
Differential DiagnosisOther disease or conditions that need to be eliminated |
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| Other infectious diseases | Other problems |
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Symptoms and effects.
The disease is common in the major river valleys of the United States where it survives in soil and animal droppings. Spores are inhaled and the commonest form of the disease is a respiratory one that usually resolves itself and in many cases fails to develop significant symptoms.
The disease can progress to systemic forms affecting all of the major organs. Commonest is a chronic pulmonary form that resembles pulmonary tuberculosis that has a productive cough, difficulty breathing, and occasional hemoptysis (coughing up of blood). In severe cases, the patient can be come cyanotic.
African histoplasmosis, caused by Histoplasma capsulata duboisii, causes ulceration and nodulation of the skin, affects the long bones and skull, the lymph nodes (lymphadenopathy) and the viscera, but does not affect the lungs.
Medical and Physical Countermeasures.
Vaccination (Immunoprophylaxis)
A vaccine is not available.
Specific Therapy
High-dose or long-term (10 weeks) therapy with antifungals amphotericin B or ketoconazole.
Supportive care
The fungus is killed by 1% sodium hypochlorite, phenolics, glutaraldehyde and formaldehyde and by moist heat (121°C, 15 min.)
Agent Properties and Potential Uses
The fungus spreads by spores (conidia) that are easily inhaled and that can survive for years under adverse conditions. It may be useful for area denial. It could also be used as a weapon of opportunity in areas where outbreaks occur, e.g. in the aftermath of an earthquake in California, to strain health care. Iraq is believed to have shown an interest in it as a weapon. Immunocompromised individuals may not be able to clear themselves of the disease and will require lifelong treatment and monitoring.
Terrorist Acquisition and Attempted Use.
| Disease | ICD-9-CM | ICD-10 |
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| Histoplasmosis | 115 | B39 |
| Acute pulmonary histoplasmosis from Histoplasma capsulatum | B39.0 | |
| Chronic pulmonary histoplasmosis from Histoplasma capsulatum | B39.1 | |
| Pulmonary histoplasmosis from Histoplasma capsulatum | B39.2 | |
| Disseminated histoplasmosis from Histoplasma capsulatum | B39.3 | |
| Infection by Histoplasma capsulatum | 115.0 | B39.4 |
| Infection by Histoplasma duboisii | 115.1 | B39.5 |
| Histoplasmosis, unspecified | 115.9 | B39.9 |
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