Capítulo 4: histoplasmose

Abstract

Histoplasmosis is systemic mycosis caused by a small fungus, Histoplasma capsulatum var. capsulatum, whose natural habitat is soil contaminated by bat or bird excrement. The incidence of histoplasmosis is worldwide. In Brazil, the disease is found in all regions; however, the state of Rio de Janeiro is responsible for most of the microepidemics described. Human infection occurs when airborne spores of H. capsulatum are inhaled. The most common clinical presentation is asymptomatic. The symptoms of acute or epidemic histoplasmosis are high fever, cough, asthenia and retrosternal pain, as well as enlargement of the cervical lymph nodes, liver and spleen. The most common radiological findings are diffuse reticulonodular infiltrates in both lungs, as well as hilar and mediastinal lymph node enlargement. In chronic pulmonary histoplasmosis, the clinical and radiological manifestations are identical to those of reinfection with pulmonary tuberculosis. Histoplasmosis is diagnosed by means of the identification or culture growth of the fungus in sputum or fiberoptic bronchoscopy specimens. Histopathological examination reveals the fungus itself within or surrounding macrophages, as well as granulomatous lesions with or without caseous necrosis. Double agar gel immunodiffusion is the most easily used and readily available serologic test for making the immunological diagnosis. Acute histoplasmosis with prolonged symptoms requires treatment, as do the disseminated or chronic pulmonary forms of the disease. The drug of choice is itraconazole.Keywords: Mycosis; Histoplasmosis; Lung diseases, fungal. ResumoHistoplasmose é uma micose sistêmica causada por um pequeno fungo, Histoplasma capsulatum var. capsulatum, cujo habitat é o solo rico em excrementos de pássaros e morcegos. A incidência da histoplasmose é mundial. No Brasil, a doença incide em todas as regiões; porém, o estado do Rio de Janeiro é responsável pelo maior número de microepidemias descritas até hoje. A infecção humana ocorre pela inalação de esporos do H. capsulatum. A forma clínica mais freqüente é a assintomática. Na histoplasmose aguda ou epidêmica, os sintomas são febre alta, tosse, astenia, dor retroesternal, acompanhados de aumento dos linfonodos cervicais, fígado e do baço. Os achados radiológicos mais frequentes são o infiltrado reticulonodular difuso em ambos os pulmões, associados a linfonodomegalias hílares e mediastinais. Na forma pulmonar crônica, o quadro clínico e radiológico é idêntico ao da tuberculose pulmonar do adulto. O diagnóstico da histoplasmose é feito pela identificação do fungo ou crescimento em cultura de escarro ou de material obtido por fibrobroncoscopia. A histopatologia identifica o fungo dentro e fora do macrófago em meio à lesão granulomatosa com ou sem necrose caseosa. A imunodifusão em duplo gel de ágar é o teste sorológico mais fácil e disponível para o diagnóstico imunológico. As formas agudas com sintomas prolongados, as formas disseminadas e a forma pulmonar crônica requerem tratamento. A droga de escolha é o itra...

Fungal pneumonia in dogs and cats with pulmonary clinical signs in southern Brazil

“…Histoplasmosis in humans and animals has a higher incidence in midwestern and the Atlantic United States and may be found in all regions in Brazil; however, in humans, the state of Rio de Janeiro is responsible for most of the microepidemics described (Aidé 2009, Brown et al 2012, Greene & Bromel 2012. In dogs and cats the disease is also found in all regions in Brazil (Silva-Ribeiro et al 1987, Carneiro et al 2005, Cordeiro et al 2011, Brilhante et al 2012, Souza et al 2015.…”

Histoplasmose simulando neoplasia primária de pulmão ou metástases pulmonares

“…The diagnosis of histoplasmosis was established by culture, histopathological examination, or immunodiffusion testing (identification of M or H precipitation bands). ( 6 ) …”

Enlarged hilar lymph node due to Histoplasma

“…Departamento de Doenças Infecciosas, Universidade Federal do Ceará, Fortaleza, Ceará, Brasil. [2]. Hospital São José de Doenças Infecciosas, Fortaleza, Ceará, Brasil.…”

“…The diagnosis of acute pulmonary histoplasmosis in patients with no history of intense exposure to this fungus is difficult. Tuberculosis and malignancies are frequently the main hypotheses (2) (3) . The elapsed time from symptom onset until seeking medical assistance may suggest an infectious agent.…”