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Histoplasmosis (also known as "Cave disease,"〔 "Darling's disease,"〔 "Ohio valley disease,"〔 "reticuloendotheliosis," "spelunker’s lung" and "caver's disease") is a disease caused by the fungus ''Histoplasma capsulatum''. Symptoms of this infection vary greatly, but the disease affects primarily the lungs. Occasionally, other organs are affected; this is called disseminated histoplasmosis, and it can be fatal if left untreated. Histoplasmosis is common among AIDS patients because of their suppressed immunity. In immunocompetent individuals, past infection results in partial protection against ill effects if reinfected. Histoplasma capsulatum is found in soil, often associated with decaying bat guano or bird droppings. Disruption of soil from excavation or construction can release infectious elements that are inhaled and settle into the lung. ==Signs and symptoms== If symptoms of histoplasmosis infection occur, they will start within 3 to 17 days after exposure; the average is 12–14 days. Most affected individuals have clinically silent manifestations and show no apparent ill effects. The acute phase of histoplasmosis is characterized by non-specific respiratory symptoms, often cough or flu-like. Chest X-ray findings are normal in 40–70% of cases.〔 Chronic histoplasmosis cases can resemble tuberculosis; disseminated histoplasmosis affects multiple organ systems and is fatal unless treated. While histoplasmosis is the most common cause of mediastinitis, this remains a relatively rare disease. Severe infections can cause hepatosplenomegaly, lymphadenopathy, and adrenal enlargement.〔 Lesions have a tendency to calcify as they heal. Presumed ocular histoplasmosis syndrome (POHS) causes chorioretinitis, where the choroid and retina of the eyes are scarred, resulting in a loss of vision not unlike macular degeneration. Despite its name, the relationship to ''Histoplasma'' is controversial.〔Thuruthumaly, C; Yee, D. C.; Rao, P. K. (2014). "Presumed ocular histoplasmosis". Current Opinion in Ophthalmology 25 (6): 508–12. doi:10.1097/ICU.0000000000000100. PMID 25237930〕〔Nielsen, J. S.; Fick, T. A.; Saggau, D. D.; Barnes, C. H. (2012). "Intravitreal anti-vascular endothelial growth factor therapy for choroidal neovascularization secondary to ocular histoplasmosis syndrome". Retina 32 (3): 468–72. doi:10.1097/IAE.0b013e318229b220.PMID 21817958〕 Distinct from POHS, acute ocular histoplasmosis may rarely occur in immunodeficiency.〔Macher, A; Rodrigues, M. M.; Kaplan, W; Pistole, M. C.; McKittrick, A; Lawrinson, W. E.; Reichert, C. M. (1985). "Disseminated bilateral chorioretinitis due to Histoplasma capsulatum in a patient with the acquired immunodeficiency syndrome". Ophthalmology 92 (8): 1159–64. PMID 2413418〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「histoplasmosis」の詳細全文を読む スポンサード リンク
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