Histoplasmosis

Histoplasmosis Most common fungal disease in U.S. Also Known As: Ohio Valley Fever Most common fungal disease in U.S. (Histoplasma Capsulatum) Histoplasmosis , A.K.A. Ohio Valley Fever, is a fungal disease of the lungs. (slide point 1). It is caused by a fungal spore, known as Histoplasma Capsulatum, and found in soil containing bird or bat droppings. Found in soil containing bird or bat droppings.

Prevalence/Statistics Ohio River Valley Mississippi river valley H. Capsulatum Histoplasma Capsulatum is prevalent in the central states, locally around ohio and mississippi river valleys, this is why it is also known as Ohio Valley Fever. The moist soil and abundant chicken farms provide ideal environments for the growth of the fungal spore. According to the CDC, 50 to 80% of the people that live in regions where H. Capsulatum is common will have been exposed to the fungus at least once in their lives.

Prevalence/ Statistics When dirt that harbors the spore is disturbed, the spore can go airborne and remain suspended in air, it is small enough to be inhaled and make home in the alveoli. The incubation is about 17 days! However, only 40% of those infected have symptoms, and 10% of those are ill enough to consult a physician.

Types of Histoplasmosis Asymptomatic Primary Histoplasmosis Acute Symptomatic Pulmonary Histoplasmosis Chronic Histoplasmosis Disseminated Histoplasmosis (slide, one by one.) Each version of histoplasmosis is progressively worse than the one before it. Asymptomatic, is the most common type of Histoplasmosis, it resolves itself in about 3 days to a week. Symptomatic histoplasmosis can include fever, cough and minor chest pain and be resolved in about a week.

Chronic Histoplasmosis Smoking and underlying lung disease such as emphysema Chronic Histoplasmosis is commonly seen in individuals who smoke and have some sort of lung disease like emphysema. The symptoms are comparable to that seen in tuberculosis, and can include fatigue, fever, hemoptysis, night sweats, SOB and sweating.

Chronic Histoplasmosis Infiltration and cavity formation in upper lobes of one or both lungs is a common characterization. As seen in the xrays. The infection is usually self-limiting, however Treatment may be required, if left untreated, it can lead to further complications and to disseminated Histoplasmosis.

Disseminated Histoplasmosis Most severe form of Histoplasmosis Immunocompromised individuals most susceptible. Disseminated histoplasmosis is normally seen in individuals poor immunity. Such as those with AIDS. The very young and the very old are also susceptible to it, because of their week immunities.

Disseminated Histoplasmosis In healthy individuals, the macrophages in the lungs are able to engulf the fungal spore, send it to the lymph node in the chest, and eliminate the infection. Those with weak immunities however, when the fungus goes to the lymph node, via the macrophage, it begins to multiply and grow. Eventually the fungus gets into the blood stream where it goes to vital organs such as the heart and brain. Untreated, will lead to death.

Diagnosis Diagnosis: fungal culture, blood analysis, sputum analysis, bronchoscopy, chest x-ray The gold standard for diagnosing is by taking a sample of the disease from the blood, sputum, lymph node, and culturing it in a lab. The process is slow however (up to 4 weeks for fungus to grow) and is usually not taken if the patient is suffering a sever form of histoplasmosis. The next method is to take a blood sample and test for antibodies. However it is inaccurate for those with weak immunities. Finally there is fungal stain method, which can use the patient sputum, and staining it with a dye. It is 100% accurate, however the disadvantage is that it can be very difficult to obtain a good sample.

Treatment Intravenous antifungal medication Fungizone Trizoles Fluconazole Itraconazole The first line of attack in treatment is the use of antifungal drugs, usually taken intravenously, and although very effective. The therapy can last anywhere from days to weeks depending on the severity of the infection. The antifungal medication can be toxic to the kidneys and can cause serious damage during prolonged use.

What can you do as an RT? I WANT YOU TO TREAT MY DISSEMINATED HISTOPLASMOSIS! The role of the RT in treating Histoplasmosis is an important one. The patient is in a constant struggle trying to maintain oxygenation levels in their bloodstream, and we have to be ready to provide the proper care. Oxygen therapy is used to treat hypoxemia that is usually brought on as a result of the consolidation and capillary shunting associated with the fungal infection. Excessive mucus production and accumulation is also associated, so bronchial hygiene is needed to clear secretions. Finally, mechanical ventilation may be indicated in severe fungal disease to support gas exchange.