Histoplasmosis: epidemiología, diagnóstico y terapéutica / Histoplasmosis: epidemiology, diagnosis and therapy

La histoplasmosis es una enfermedad granulomatosa, producida por hongos dimorfos del género Histoplasma. Se observa en casi todos los países del mundo. En América Latina, en Venezuela, Colombia, Brasil, Argentina, Ecuador, Perú, Paraguay y Uruguay, entre otros. Datos epidemiológicos recienteshanmostrado un aumento de histoplasmosis en Venezuela y otros países.Los clínicos no están conscientes de su importancia en nuestro medio. Objetivo: Dar a conocer la situación actual de esta enfermedad en el Area Metropolitana de Caracas y en otras áreas endémicas, con la intención de crear la inquietud de investigar su incidencia y otras características relevantes en el resto del país. Métodos: Se analizaron las características de todos los pacientes con diagnóstico de certeza de histoplasmosis registrados y realizados por la Sección de Micología Médica ­Dr. Dante Borelli‖ del Instituto de Medicina Tropical de la UCV, referidos de los diferentes hospitales del Distrito Capital y otros estados del país, con énfasis en los datos epidemiológicos, manifestaciones clínicas, diagnóstico, tratamiento y evolución entre 1994 y 2012. Resultados: se encontraron 553 pacientes. La mayoría estaban entre los 20 y 49 años, relacionado con un alto número de pacientes con VIH/SIDA. Hubo más casos en hombres que en mujeres en todos los grupos etarios, menos en los pacientes mayores de 60 años, posiblemente debido a la disminución de los estrógenos, que son protectores en la mujer. Casi todos los pacientes con VIH/SIDA mostraron la forma diseminada, solo uno presentó una forma pulmonar. De los pacientes VIH negativos, 54,62% presentaron infección diseminada y 44,47%, formas pulmonares. 93 de los de enfermedad diseminada tenían estados de inmunocompromiso. El examen directo fue el método más fácil y eficaz para diagnosticar la histoplasmosis. La anfotericina B (AMB) fue el tratamiento para la histoplasmosis en pacientes con o sin SIDA, que requirieron hospitalización, seguido por itraconazol (ITC). Esta droga se utilizó en pacientes que no se encontraban severamente enfermos o con afectación del sistema nervioso central. Conclusiones: histoplasmosis se encuentra en aumento en nuestro país. Se observa con más frecuencia en pacientes con SIDA, inmunosuprimidos y pacientes que han recibido un inóculo abundante. El examen directo con coloraciones especiales es el método de mayor rendimiento para el diagnóstico. Este debe ser realizado por personal con experiencia.Es conveniente utilizar diferentes técnicas para aumentar la probabilidad de obtener un diagnóstico correcto. AMB e ITC son los tratamientos de elección. Los médicos deben estar alertas de los signos y síntomas, correlacionándolos con los antecedentes epidemiológicos, para evitar el retraso del diagnóstico y mejorar la evolución de los pacientes.

Histoplasmosis is a granulomatous disease, caused by dimorphic fungi from the genus Histoplasma. It is described worldwide.In Latin America, Venezuela, Colombia, Brasil, Argentina, Ecuador, Perú, Paraguay and Uruguay among others are affected. Recent epidemiological data have shown an increase of histoplasmosis in Venezuela and other countries. Clinicians are nor aware of the importance of this mycosis. Objective: analyze the current situation of this disease in the Caracas Metropolitan Area and other endemic areas, with intention to create awareness of its incidence and other relevant characteristics in our country. Methods: characteristics of the patients with diagnosis of histoplasmosis, performed and registered at the Sección de Micología Médica ­Dr. Dante Borelli‖, Instituto de Medicina Tropical, UCV, referred from different hospitals at Distrito Capital and other states of the country, with emphasis on epidemiological data, clinical manifestations, diagnosis, treatment and outcome, between 1994 and 2012 are analized. Results: 553 patients were found. Most of them were between 20 and 49 years old, possibly due to a high number of HIV/AIDS patients. There were more male than female patients in all age groups, except in 60 years and older, possibly due to the lack of estrogenic hormones, which protect women from infection. All HIV/AIDS patients but one, presented with a disseminated form of the disease, and one, a pulmonary form. Of the HIV negative patients, 54,62% showed disseminated infection and 44,47%, pulmonary presentation. 93 of the disseminated infection patients had immunocompromising conditions. Direct examination was the easiest and most efficacious diagnostic method. Amphotericin B (AMB) was the drug of choice for the treatment of hospitalized patients, followed by Itraconazole (ITC). This was the preferred treatment for mild to moderate disease or non CNS infection. Conclusions: Histoplasmosis is rising in our country. It is more frequent in HIV/AIDS patients and immune suppression. It is also seen in patients who have inhaled a large inoculum. Direct examination with special stains is the diagnostic method with better results. It must be performed by experienced personnel in fungal diagnosis. The use of different techniques is recommended to improve early and correct diagnosis. AMB and ITC are drugs of choice for the treatment of histoplasmosis. Clinicians should be aware of suggestive symptoms and signs, correlating them with epidemiological data, to avoid diagnostic delay and improve the outcome of the patients.

Boletim epidemiológico: perfil de pacientes com micoses sistêmicas notificados de 2013 a 2018 em hospital de referência do estado de Goiás / Epidemiological bulletin: profile of patients with systemic mycoses notified from 2013 to 2018 in a reference hospital in the state of Goiás

Micoses Sistêmicas são infecções fúngicas causadas por patógenos primários cujo trato respiratório é utilizado como porta de entrada, mas ocasionalmente se disseminam para todo o organismo. As micoses sistêmicas consideradas endêmicas no Brasil são: paracoccidioidomicose, histoplasmose, coccidioidomicose e criptococose. Por se tratarem de doenças fúngicas emergentes constata-se a necessidade de implantação de uma vigilância epidemiológica eficaz, que tenha impacto positivo na saúde pública no que diz respeito à elaboração de diretrizes e execuções de ações para prevenção, tratamento, e controle dessas micoses. Desta forma, este boletim tem como objetivo descrever o perfil de pacientes com micoses sistemas notificados em hospital de referência de Goiás. Trata-se de um estudo transversal descrito, quantitativo, com dados obtidos do Sistema de Informação de Agravos de Notificação (SINAN-NET) de um Núcleo Hospitalar de Vigilância Epidemiológica do estado de Goiás no período de 2013 a 2018

Systemic mycoses are fungal infections caused by primary pathogens whose respiratory tract is used as a gateway, but occasionally disseminate throughout the body. The systemic mycoses considered endemic in Brazil are: paracoccidioidomycosis, histoplasmosis, coccidioidomycosis and cryptococcosis. As they are emerging fungal diseases, there is a need to implement effective epidemiological surveillance, which has a positive impact on public health with regard to the elaboration of guidelines and execution of actions for the prevention, treatment, and control of these mycoses. Thus, this bulletin aims to describe the profile of patients with systemic mycoses reported in a referral hospital in Goiás. This is a descriptive, quantitative, cross-sectional study with data obtained from the Notifiable Diseases Information System (SINAN-NET) of a Hospital Center for Epidemiological Surveillance in the state of Goiás from 2013 to 2018

Predictive factors for disseminated histoplasmosis in AIDS patients with fever admitted to a reference hospital in Brazil

Abstract INTRODUCTION: In many settings, the lack of sensitive biomarkers of disseminated histoplasmosis (DH) leads to a clinical reliance on older diagnostic methods and delayed treatment initiation. The early recognition of DH is critical for survival, especially in patients with human immunodeficiency virus (HIV). This study aimed to identify clinical and laboratory findings associated with the definitive diagnosis of DH in low-income HIV patients in endemic areas. METHODS: Febrile AIDS patients with suspected DH who were admitted to a reference hospital in northeastern Brazil from January 2006 to January 2007 were evaluated for clinical and laboratory findings associated with DH diagnosis. RESULTS: One hundred seventeen patients with fever were included, and 48 (41%) cases of DH were determined by Histoplasma capsulatum identification. A higher fever (≥38.5ºC), maculopapular/papular rash, splenomegaly, hepatomegaly, wheezing, hemoglobin ≤9.5g/dL, platelets ≤80,000/µL, CD4 count ≤75/µL, aspartate aminotransferase (AST) level ≥2.5 times the upper limit of normal (ULN), lactate dehydrogenase (LDH) ≥5times the ULN; and international normalized ratio (INR) >2 times the ULN were significantly associated with DH. A multivariable analysis identified hepatomegaly [adjusted (a) prevalence ratio (PR)= 1.96; 95% confidence interval (CI): 1.21-3.16), CD4 count ≤75/µL (aPR = 2.02; 95% CI: 1.06-3.83), LDH ≥5 times the ULN (aPR = 2.23; 95% CI: 1.44-3.48), and maculopapular/papular rash (aPR = 1.70; 95% CI: 1.02-2.83) were independent risk factors for DH. CONCLUSIONS: These easily assessed parameters can facilitate clinical decision-making for febrile AIDS patients with suspected DH in low socioeconomic and Histoplasma-endemic regions.

Histoplasmosis diseminada en pacientes HIV/SIDA: Buenos Aires, 2009-2014 / Disseminated histoplasmosis in patients with AIDS. Buenos Aires, 2009-2014

Durante 2009-2014, en nuestro hospital fueron diagnosticados 171 casos de histoplasmosis en pacientes con HIV/sida: 64 en 2009-2011, y 107 en 2012-2014. El mayor número de casos durante el segundo trienio no tuvo relación con la infección por HIV, cuya tasa de diagnóstico permaneció estable. La relación hombre/mujer fue 3.7:1 y la edad media 37.4 años. Al diagnóstico, solo 54/171 (31.6%) recibían TARGA y el recuento de linfocitos T CD4+ varió entre 4 y 264 células/μl. El 64.3% (n = 110) presentó lesiones cutáneas (pápulas ulceradas o "moluscoides") positivas para Histoplasma capsulatum al examen microscópico con tinción Giemsa. Siguieron en frecuencia las manifestaciones respiratorias y el lavado broncoalveolar fue positivo en 41/171 (24.0%) pacientes. Las imágenes radiológicas más frecuentes en orden decreciente fueron patrón miliar, infiltrados intersticiales y condensaciones focales. Se aisló H. capsulatum en 82 (58.2%) de los 141 hemocultivos realizados. No hubo diferencia significativa entre el rendimiento diagnóstico del hemocultivo y el de las escarificaciones cutáneas (p = 0.6164). Otras infecciones oportunistas previas o concomitantes con la histoplasmosis se observaron en 70/171 (40.9%). Se registró asociación con tuberculosis en 16/171 (9.4%) y un aislamiento de Mycobacterium tuberculosis resultó multirresistente. La gravedad del caso determinó el tratamiento con anfotericina B desoxicolato en 115 (67.3%), con itraconazol en 43 (25.1%), y con terapias combinadas en 14 (8.2%). La letalidad fue 19.9% (34/171). La mayor prevalencia en el segundo trienio debe alertar a la comunidad médica a considerar el diagnóstico de la histoplasmosis en pacientes con HIV/sida para disminuir la mortalidad.

A retrospective study was carried out on 171 cases of disseminated histoplasmosis diagnosed in HIV/AIDS patients during the period 2009-2014. Although HIV diagnosis rates remained stable over the study period, a sensible increase in the number of histoplasmosis cases was observed in the last three years. Disseminated histoplasmosis was prevalent in males with an average age of 37.8 years. At diagnosis, only 54/171 (31.6%) were receiving HAART, and CD4+ T-lymphocyte counts ranged from 4 to 264 cells/μl. Cutaneous lesions, including ulcerated papules or molluscoid plaques, were present in 110/171 (64.3%), with Histoplasma capsulatum being observed in all skin scraping specimens upon Giemsa staining. Respiratory manifestations were second in frequency with bronchoalveolar lavage showing a high diagnostic performance. Radiological findings included milliary patterns, interstitial infiltrates, and focalized condensations. Out of 141 blood cultures performed, H. capsulatum was isolated in 82 (58.2%). No significant difference in diagnostic performance was found between blood cultures and skin scraping (p = 0.6164). Other opportunistic infections were observed in 70/171 (40.9%) prior to or concomitantly with histoplasmosis. Association with Mycobacterium tuberculosis was recorded in 16/171 (9.4%) and one had a multi-drug resistant isolate. The severity of histoplasmosis determined the monotherapy with amphotericin B deoxycholate in 115 (67.3%), itraconazole in 42 (24.5%), and combined therapies in 14 (8.2%). Mortality was 19.9% (34/171). Finally, we emphasize that the higher prevalence in the last three years of the study should prompt the medical community to consider the diagnosis of histoplasmosis to reduce mortality of AIDS patients.

Immunological assays employed for the elucidation of an histoplasmosis outbreak in São Paulo, SP

Several reports showed outbreaks of histoplasmosis acquired while bat-inhabited caves were visited by tourists, miners or researchers. We evaluated the performance of double immunodifusion (DI) and immunoblotting (IB) assays, employed for the histoplasmosis outbreak elucidation occurred in Vale do Paraíba, São Paulo. The existence of epidemiologic link, four patients with clinical signs suggestive of histoplasmosis and mycological confirmation has made that all 35 individuals involved to the cave visit were subjected to serological evaluation. By DI, we observed reactivity against H. capsulatum antigen in a single serum examined nearly 20 days after exposure to fungal propagules. On the other hand, IB showed reactivity against H and M fractions in 50% of samples evaluated. The analysis of the second sample batch, collected two months after the exposure showed that 96.7% were reactive by DI with antibodies titers ranging from 1 to 16 and 100% of reactivity against H and M fractions, by IB, suggesting an acute infection. The analysis of the overall agreement between the methods showed to be reasonable (κ = 0.37). This study confirms the importance and efficacy of more sensitive methodologies, such as IB assay, to early elucidation of disease, especially in cases of patients without mycological information.

Histoplasmosis, epidemiología, clínica y tratamiento / Histoplasmosis, epidemiology, clinical and treatment

Describir las características clínico epidemiológicasy estrategias diagnóstico-terapéuticas, asociadas a infección por Histoplasma capsulatum en el Hospital Universitario de Caracas. Estudio descriptivo, retrospectivo y de cohorte. Se realizó la recolección de datos de las historias clínicas de los pacientes con diagnóstico de infección por Histoplasma capsulatum del Hospital Universitario de Caracas durante los años 1999-2009. De 105 pacientes estudiados, se evidencia que predomina el grupo etario de 22 a 46 años, 77,1% son hombres, 49,5% tienen hábito tabáquico, 7,6% se relacionó con construcciones y remodelaciones. La fiebre fue la manifestación clínica más frecuente 84,8%. El diagnóstico se realizó mediante serología en 56,2%, y las muestras biológicas procesadas en mayor número fueron sangre y médula ósea con 49,5%. La presentación más frecuente fue la histoplasmosis diseminada. El tratamiento fue con anfotericina B e itraconazol, la mayoría de los pacientes evolucionaron hacia la mejoría. La histoplasmosis es la infección oportunista endémica más frecuente, especialmente en pacientes con VIH-SIDA,la serología fue el método de diagnóstico de mayor rendimiento. El tratamiento con anfotericina B e itraconazol fue el preferido, la mayoría de los pacientes mejoró. Es importante el estudio de las enfermedades endémicas en nuestros pacientes, especialmente aquellos con VIH-SIDA

To describe the clinical and epidemiological characteristics and diagnostic-therapeutic strategies associated with Histoplasma capsulatum infection at the University Hospital of Caracas. A descriptive, retrospective cohort study. We performed a data collection from medical records of patients diagnosed with Histoplasma capsulatum infection at Caracas University Hospital during the years 1999-2009. Of 105 patients studied, the predominant age group was 22-46 years old, 77.1% male, 49.5% had smoking habits, 7.6% were related to construction and renovation. Fever was the most common clinical manifestation 84.8%. The diagnosis was made by serology in 56.2%, and biological samples processed in highest number were blood and bone marrow with 49.5%. The most common presentation was disseminated histoplasmosis. The preferred treatment was amphotericin B and itraconazole, most patients evolved toward improvement. Histoplasmosis is the most common endemic opportunistic infection, especially in patients with HIV-AIDS; serology was the main diagnostic method. Treatment with amphotericin B and itraconazole was preferred, most of the patients improved. It is important to study endemic diseases in our patients, especially those with HIV-AIDS

Histoplasmosis oral atípica en paciente VIH reactivo: reporte de un caso / Atypical oral histoplasmosis in a HIV-reactive patient: report of a case

La histoplasmosis es una infección granulomatosa causada por un hongo dimórfico, el Histoplasma capsulatum. Clínicamente, existen tres formas: aguda, crónica y diseminada. Nosotros presentamos un caso de un paciente masculino de 19 años, reactivo para el VIH, en el estado C, quien fue derivado al Servicio de Odontología Hospital Juan A. Fernández, Buenos Aires, Argentina, en donde se realizó una evaluación estomatológica. El paciente presentaba erosiones, pápulas y nódulos indoloros de aproximadamente 2,4 mm en la mucosa bucal. Se realizaron tres biopsias correspondientes a cada tipo de lesión presente. Los estudios histológicos revelaron invasión celular por Histoplasma capsulatum. Este caso de reporta como una forma atípica de histoplasmosis en base a lesiones diferentes entre sí, lo cual hizo el diagnóstico difícil. Es común la observación de presentaciones inusuales de lesiones bucales en pacientes VIH positivos.

Histoplasmosis in immunocompetent individuals living in an endemic area in the Brazilian Southeast

Introduction The distribution of infection by Histoplasma capsulatum in Brazil is heterogeneous, and the number of cases affecting immunocompetent individuals is relatively small. This study reports the epidemiological and clinical data regarding histoplasmosis in non-immunosuppressed individuals. Methods The study included only the immunocompetent patients with histoplasmosis who were diagnosed between 1970 and 2012 at a university hospital located in Ribeirão Preto, State of São Paulo, Brazil. Clinical and epidemiological data were collected retrospectively from the patient records. Results Of the 123 patients analyzed, 95 had an active disease that manifested in the different clinical forms of histoplasmosis. Men were the predominant gender, and most patients resided in the Northeast of the State of São Paulo and in the nearby municipalities of the State of Minas Gerais. The risk factors for acquiring histoplasmosis and prolonged contact in a rural environment were recorded in 43.9% and 82.9% of cases, respectively. Smoking, alcoholism, and comorbidity rates were high among the patients with the chronic pulmonary and subacute/chronic disseminated forms of histoplasmosis. Many patients achieved clinical cure spontaneously, but 58.9% required antifungals; the disease lethality rate was 5.3%. Conclusions Immunocompetent individuals manifested the diverse clinical forms of histoplasmosis over a period of 4 decades, revealing an additional endemic area of this fungal disease in the Brazilian Southeast. .

Ferramentas proteômicas na identificação de novos alvos antigênicos na proteína M do Histoplasma capsulatum e aplicação em ensaios imunoenzimáticos / Proteomic tools to identify new targets in the M protein antigen of Histoplasma capsulatum and application to immunoassays

A histoplasmose é uma infecção que apresenta amplo espectro clínico, variando desde forma leves, a graves e disseminadas. O diagnóstico da histoplasmose baseia-se nos aspectos clínicos, radiológicos e epidemiológicos. A confirmação se dá pelo isolamento e identificação do Histoplasma capsulatum através de procedimentos microbiológicos. [...] O antígeno M obtido do extrato antigênico histoplasmina é considerado um antígeno imunodominante para produção de anticorpos, sendo reconhecido em cerca de 90 porcento dos soros dos pacientes com histoplasmose, sendo assim nosso grupo vem trabalhando a vários anos em estudos para um melhor conhecimento desta molécula e aplicação no diagnóstico.Um Modelo molecular do antigeno M foi desenvolvido através de sua sequência, tendo então confirmada sua natureza biológica como catalase, sendo observado também que esta molécula apresentava regiões comuns bem como especificas quando comparadas a catalases de organismos eucariotas. No presente estudo procuramos determinar a presença de possíveis epitopos antigênicos na proteína M empregando ferramentas proteômicas, para posterior emprego em ensaios imunoenzimáticos. Para tal foi utilizada a combinação da técnica de coimunoprecipitação com espectometria de massas e posteriormente a técnica de Spot synthesis. Com o emprego do anticorpo monoclonal (mAb 1A7) produzido contra a proteína M recombinante foi possível detectar uma sequência que foi comum as duas metodologias empregadas (PTKIIPEELVPFTP). Esta sequência encontra-se localizada na região onde em estudos anteriores por análise in silico foi apontada como a região mais antigênica desta molécula. Foi realizada a síntese desta sequência, e diferentes desenhos foram utilizados, extensão de resíduos de lisina e adição da molécula de biotina em ambas as extremidades, carboxi e amino terminal, bem como a síntese da sequência sem adição de outras moléculas. Diferentes desenhos de ensaios imunoenzimáticos foram realizados, um ELISA empregando microesferas carboxiladas, ELISA indireto empregando placas de microtitulação revestidas com estreptoavidina e um ELISA sandwich. A sequência não apresentou resultados satisfatórios nos diferentes ensaios. Observamos que apenas no ensaio onde utilizamos o peptídeo ligado a molécula de biotina 1-a e 1-b, foi possível obter um poder discriminatório entre o grupos de pacientes com histoplasmose e o grupos de indivíduos hígidos, o ponto de corte foi obtido pela media das DOs das amostras de indivíduos hígidos mais duas vezes o desvio padrão, onde este teste apresentou uma boa sensibilidade(100 - 95 porcento), porém a especificidade encontrada não foi satisfatória (27 - 20 porcento). Estes resultados não foram concordantes com a análise feita in silico da sequência sintetizada. O antígeno M recombinante foi testado em um ELISA de captura de antígeno, onde os resultados preliminares apresentaram-se promissores necessitando de novos testes para avaliarmos parâmetros como sensibilidade e especificidade.

Histoplasmosis is a worldwide distribution infection with several clinical spectrum, from asymptomatic to severe and disseminated disease. The diagnosis of histoplasmosis is based onclinical, radiological and epidemiological findings. The laboratory diagnosis of histoplasmosis is based on fungus isolation by culture, direct examination in tissue or other clinical specimens. However, such procedures have limitations and are time-consuming. For these reasons serological tests play an important role on presumptive diagnosis. [...] The M antigen is obtain by the antigenic extract histoplasmin and is considered as an immunodominant antigen recognized by 90 percent of sera from patients with histoplasmosis, For a better understanding of the molecule biological nature and its application in diagnosis methodologies our group has been working for several years. The molecular analysis of the M antigen was based on the sequence protein and confirmed as a catalase. It was also observed that this molecule showed specific and common polypeptide regions when compared to catalases from others eukaryotic organisms. In this study we evaluated the possible presence of antigenic epitopes in the M protein sequence that could represent potential candidate as diagnostic markers for histoplasmosis. For this reason we used the combining co-immunoprecipitations and mass spectrometry and spot synthesis technique. The application of a monoclonal antibody against to the M antigen (mAb 1A7) produced by our group allowed the detection of a same sequence in both employed methodologies (PTKIIPEELVPFTP). This was synthesized with different conformations, addition lysine residues and biotin molecules in both amino and carboxy terminal regions. Different immunoassays were performed, carboxylated microspheres, ELISA indireta with microplate coated with streptoavidin and ELISA sandwich. The sequence did not show good specificity and sensibility in different tests. A good discriminatory power was possible when the peptide biotin molecule bind (P1-a and P1-b) was used in serum samples from groups of histoplasmosis patients and healthy controls. This test showed a high sensitivity (100-95 percent), however the specificity was not satisfactory (27-20 percent) respectevily. The ELISA´s cut-off points were established as the mean of absorbances plus two standard deviation of the healthy controls. The immunoassay´s results were discordant when compared on in silico analysis using as antigen the synthesized sequence. In another approach, the M antigen was tested in an antigen-capture enzyme-linked immunosorbent assay (ELISAs) and promising results were observed, but further studies must be done in order to evaluate parameters such as sensitivity and specificity.

Tuberculosis y micosis sistémicas en indígenas del Municipio Cedeño Estado Bolívar Venezuela / Tuberculosis and systemic mycoses in indigenous Cedeño Municipality Bolivar State Venezuela

Determinar la prevalencia de tuberculosis y micosis sistémicas endémicas, Paracoccidioidomicosis e Histoplasmosis, en poblaciones indígenas. Se realizó un estudio transversal en pacientes sintomáticos respiratorios de 3 comunidades indígenas del municipio Cedeño del estado Bolívar, Venezuela. Se obtuvieron muestras de esputo y secreción ganglionar para la búsqueda de bacilos ácido-resistentes, el complejo Paracoccidioides sppe Histoplasma capsulatum; se realizó cultivo en medio Lowëstein Jensen y medios selectivos para hongos, además estudio molecular para micobacterias. Se estudiaron muestras de suero para la demostración de anticuerpos específicos contra el Complejo Paracoccidioides sppe H. capsulatum. Se evaluaron 60 pacientes sintomáticos respiratorios. Se demostraron bacilos ácido-resistentes por baciloscopia en 26 casos (43,3%) y 29 cultivos positivos para Mycobacterium tuberculosis (48,3%) resultando un total de 33 pacientes con diagnóstico de tuberculosis; hubo correlación significativa entre los hallazgos en el Ziehl-Nielsen y el crecimiento de M. tuberculosis en cultivo (p=0,013). Se demostró la presencia del Complejo Paracoccidioides spp en 2 casos (3,3%), con coexistencia de bacilos ácido-resistentes. No se evidenció la presencia de H. capsulatum. La tuberculosis constituye la principal causa de infección respiratoria crónica en estas comunidades indígenas y obliga a que se revisen de forma urgente los programas regionales para la atención de estas poblaciones vulnerables, así como a realizar estudios en otras poblaciones.

To determine prevalence of tuberculosis and endemic systemic mycoses, Paracoccidiodomycosis (PCM) and Hystoplasmosis in native populations. A transversal study in individuals with respiratory symptoms from 3 native populations from Cedeño County from Bolivar state, Venezuela, was realized. Sputum and spontaneous lymphatic node secretion samples were obtained to look for acid-resistant bacilli, Paracoccidioides spp complex and Histoplasma capsulatum. Culture in Lowëstein-Jensen and selective media to fungi, andmolecular study formycobacteria were realized. Serum samples were studied to demonstrate specific antibodies against Paracoccidioides spp complex and H. capsulatum. Sixty individuals had respiratory symptoms. Acid-resistant bacilli were demonstrated in 26 cases by bacilloscopy (43.3%) and 29 positive cultures for Mycobacterium tuberculosis (48.3%), resulting 33 patients with diagnosis of tuberculosis; there was significative correlation between features in bacilloscopy and growing of M. Tuberculosis in Lowëstein-Jensen media (p=0.013). Presence of the characteristic yeastlike forms of Paracoccidioides spp complex was found in 2 cases (3.3%) with coexistence of acidresistant bacilli in both. There was no evidence of H. capsulatum. Tuberculosis constitutes the principal origin of chronic respiratory infection in these native populations and it should conduce to revise urgently the regional programs attending to these vulnerable populations.

Brote de histoplasmosis de primoinfección en cinco hermanas / Epidemic outbreak of histoplasmosis primary infection in five sisters

La histoplasmosis clásica o capsulati es una infección fúngica endémica en América, causada por un hongo dimorfo denominado Histoplasma capsulatum var. capsulatum. Es una micosis endémica en amplias áreas de América del Norte, Central y del Sur. La primoinfección se adquiere a partir de lainhalación de las microconidias del hongo que están presentes en el medio ambiente, especialmente en grutas y cavernas habitadas por murciélagos y en suelos con deyecciones de gallinas y de palomas. Las manifestaciones clínicas de la infección primaria son incaracterísticas y varían desdeinfecciones asintomáticas hasta enfermedad grave, lo que depende de la cantidad de conidias inhaladas. En este trabajo se describe un brote de primoinfección por Histoplasma capsulatum var. capsulatum en cinco hermanas, oriundas de la localidad de San Isidro, provincia de Buenos Aires,ocurrido durante un viaje en automóvil por el norte de la República Argentina, que incluyó las provincias de Santiago del Estero y Tucumán. Cuatro de ellas presentaron manifestaciones clínicasleves a moderadas de enfermedad respiratoria aguda; la restante, en cambio, desarrolló un cuadro clínico grave, con manifestaciones infrecuentes, como conjuntivitis flictenular, eritema nudoso y artralgias. Todas evolucionaron de manera favorable sin requerir tratamiento antifúngico.

Una actualización acerca de histoplasmosis / Histoplasmosis updating

La histoplasmosis infección causada por el hongo Histoplasma capsulatum ha sido reportada en todos los continentes y se considera endémica en el continente americano, incluida Cuba. El hongo se desarrolla en el suelo con excretas de aves y murciélagos, donde es capaz de producir abundantes microconidios, que al ser inhalados por el hombre son capaces de causar la infección. El cuadro clínico puede variar, desde infecciones asintomáticas hasta cuadros diseminados graves que involucran a uno o varios órganos y sistemas y que afectan sobre todo a pacientes con sida, neoplasias hematológicas, con trasplantes u otras inmunodeficiencias. Los principales grupos de riesgo incluyen además, aquellos individuos que por razones ocupacionales se expongan los aerosoles contaminados con el hongo. El diagnóstico de laboratorio se basa en la observación de este en fluidos y tejidos orgánicos, en el cultivo de esos materiales y en la detección de anticuerpos y antígenos específicos. Los métodos moleculares, en especial mediante la reacción en cadena de la polimerasa, aunque no han sido suficientemente evaluados, pudieran representar un importante avance en el diagnóstico temprano de esta micosis. Para el tratamiento de las formas agudas moderadas, localizadas y respiratoria crónica se recomienda el itraconazol, mientras que para las formas graves y diseminadas la droga de elección es la anfotericina B, con preferencia en alguna de sus formulaciones lipídicas. La histoplasmosis representa hoy una de las micosis sistémicas más importante en las Américas, con una amplia distribución en todas las regiones de Cuba.

Histoplasmosis, an infection caused by the fungus Histoplasma capsulatum, has been reported all over the world and is considered endemic in the American continent, including Cuba. This fungus grows on the soils contaminated with bird and bat excreta, where it produces a great number of microconidia that could cause the infection when they are inhaled. The clinical spectrum varies from asymptomatic infections to serious disseminated diseases involving one or many organ systems and affects mainly AIDS patients, patients with hematological neoplasias, transplant recipients or other immunosuppressed patients. The main risk groups include those individuals whose working activities make them be exposed to aerosols contaminated with H. capsulatum. Lab diagnosis is based on the microscopic observation, isolation and identification of the fungus in fluid or tissue samples of patients, and on specific antigen and antibodies detection. The molecular methods based on polymerase chain reaction have not been sufficiently defined, and they could be an important advance in the early diagnosis of this mycosis. Itraconazole is recommended for treatment of moderate, localized and chronic infection whereas amphotericin B is the drug of choice for disseminated and serious manifestations, particularly in its lipidic formulations. At present, histoplasmosis is considered one of the most important systemic mycoses in the Americas, and it is widely spread over all regions of Cuba.

Brote de histoplasmosis en la Escuela de Cadetes de la Base Aérea de Morón, Provincia de Buenos Aires, República Argentina / Histoplasmosis outbreak in Morón, Buenos Aires Province, Argentina

Se describe un brote de histoplasmosis que afectó a 6 cadetes de la Fuerza Aérea Argentina, sin antecedentes patológicos previos. Todos consultaron por problemas respiratorios después de haber limpiado un hangar. En ese recinto se encontraron abundantes deyecciones de animales, presuntamente de palomas y murciélagos. Los pacientes sufrieron fiebre, mialgias, taquipnea y tos no productiva. Las radiografías y tomografías de tórax mostraron imágenes pulmonares micronodulares, engrosamiento de los tabiques interalveolares y adenopatías hiliares. Todos tuvieron una evolución favorable y no requirieron tratamiento antifúngico. Las pruebas de inmunodifusión y contrainmunoelectroforesis con antígenos de Histoplasma capsulatum fueron positivas, al igual que las intradermorreacciones con histoplasmina. Se recogieron 5 muestras de tierra del lugar, las que fueron inoculadas por vía intraperitoneal a 20 hámsteres. De los cultivos de hígado y bazo de dichos animales se consiguió aislar la fase micelial de H. capsulatum. La cepa aislada se comparó con las obtenidas de 12 pacientes argentinos utilizando perfiles genéticos y se observó un clado único con más de 96% de similitud, lo que confirma la homogeneidad de las cepas argentinas. Si bien la histoplasmosis es endémica en la Pampa húmeda, este es el primer brote totalmente documentado al sur del paralelo 34°.

An histoplasmosis outbreak affecting 6 previously healthy Air Force cadets is herein presented. The patients suffered from fever and respiratory symptoms after having cleaned an abandoned hangar soiled with pigeons and bat droppings. They all presented fever, myalgia, tachypnea, and nonproductive cough. Chest X-ray and CT scan studies showed disseminated reticulonodular images affecting both lungs. Hiliar adenomegalies were also observed. All patients achieved a favourable outcome without antifungal treatment. Both serologic tests searching for specificic antibodies (immunodiffusion and counterimmunoelectrophoresis) and histoplasmin skin tests were positive in all cases. Five soil samples mixed with pigeons and bat droppings were collected from the hangar. Suspensions of these samples were inoculated into 20 hamsters by intraperitoneal injection; mycelial phase of H. capsulatum was isolated from liver and spleen cultures. The genetic profile of this strain was compared with 12 isolates obtained from Argentinean patients, and a great degree of homogeneity was observed (> 96% similarity). Although histoplasmosis is endemic in the wet Pampas, this is the first epidemic outbreak reported south of the 34th parallel.

Histoplasmosis en pacientes con sida: Un estudio de cohorte en Medellín, Colombia / Histoplasmosis in AIDS patients: A cohort study in Medellín, Colombia

Introducción: la histoplasmosis es una micosis endémica en nuestro país y una complicación relativamente frecuente de los pacientes con sida. El objetivo del estudio era identificar las características clínicas, epidemiológicas y los factores de riesgo asociados a la mortalidad en pacientes con sida coinfectados con histoplasmosis. Materiales y métodos: se realizó un estudio de cohorte retrospectivo en el Hospital Universitario San Vicente de Paúl, en Medellín, con 1177 pacientes con VIH atendidos en un programa especializado de sida. Se identificaron los pacientes con histoplasmosis confirmada por aislamiento del hongo, o identificaci&oacut compatibles con Histoplasma capsulatum, mediante microscopía. Se analizaron variables demográficas, clínicas, de laboratorio, comorbilidad, tratamiento recibido y mortalidad. Resultados: La histoplasmosis afectó a 44 de 709 pacientes con sida (6,2%). Entre éstos, el 95,4% tuvo fiebre, el 54,5% enfermedad diseminada e;n de levaduras intracelulares y el 61,3% compromiso pulmonar. El cultivo fue positivo en el 89,3% y la histopatología en el 93,3%. Se encontró tuberculosis concomitante en el 15,9% y neumocistosis en el 11,4%. La mortalidad fue del 22,7%. El riesgo de morir fue mayor en pacientes con formas diseminadas (todas las muertes ocurrieron en sujetos con este tipo de compromiso), disnea (RR 13; IC95% 1,8-93,8), hipotensión (RR 4,5; IC95% 1,6-13,1), deshidrogenasa láctica (DHL) >2 veces (RR 5,2; IC95% 1,2-22,5), y fue menor en quienes recibieron Anfotericina B (RR 0,3; IC95% 0,1-0,8). Discusión: en la región, la histoplasmosis es frecuente en pacientes con sida, y el rendimiento diagnóstico de las técnicas de rutina para H. capsulatum es alto, por lo que deben solicitarse en cualquier caso compatible. Demostrar la comorbilidad sida-histoplasmosis no descarta otras infecciones oportunistas. Los pacientes con formas diseminadas, disnea, hipotensión y DHL alta tienen mayor riesgo de muerte. El tratamiento con anfotericina B se asoció con una mayor sobrevida.

Introduction: histoplasmosis is an endemic mycosis in Colombia and a relatively common complication in HIV patients. The aim of this study was to identify clinical and epidemiological characteristics and mortality risk factors in patients infected with histoplasmosis and HIV. Materials and methods: a retrospective cohort study was carried out at Hospital Universitario San Vicente de Paúl in Medellín with 1177 HIVpositive patients. Patients with histoplasmosis were confirmed by isolation of Histoplasma capsulatum from culture or by identification of intracellular yeasts through microscopy. Data collected from patients included demographic and clinical variables, laboratory values, treatment, and survival. Results: histoplasmosis affected 44/709 patients with AIDS (6.2%). Out of those, 95.4% had fever, 54.5% disseminated illness, and 61.3% pulmonary disease. Culture was positive in 89.3%, and histopathology in 93.3%. Concomitant tuberculosis and Pneumocystis jirovecii infection were diagnosed in 15.9% and 11.4%, respectively. General mortality was 22.7%. Mortality was higher in patients with disseminated forms (all 10 deaths occurred in this fashion), dyspnea (RR 13; 95% CI 1.8-93.8), hypotension (RR 4.5; 95% CI 1.6-13.1), lactate dehydrogenase >2 times the upper limit of the normal range (RR 5.2; 95% CI 1.2-22.5), and it was lower among patients treated with amphotericine B (RR 0.3; 95% CI 0.1-0.8). Discusion: histoplasmosis is frequent in AIDS patients in the region. As the diagnosis yield of routine techniques to identify H. capsulatum is high, they must be required in any compatible setting. Many patients with AIDS-histoplasmosis co-infection acquire other opportunistic infections. Patients with disseminated forms, dyspnea, hypotension, and high levels of DHL have a higher mortality risk. Exposure to amphotericine B is associated with longer survival.

Brotes de histoplasmosis ocupacional en la provincia La Habana / Outbreaks of occupational acquired histoplasmosis in La Habana province

INTRODUCCIÓN: la histoplasmosis, infección causada por el hongo Histoplasma capsulatum, está considerada una de las principales micosis endémicas del continente americano, donde se presenta frecuentemente en forma de brotes epidémicos. En Cuba, la mayoría de ellos han estado relacionados con la realización de actividades de riesgo en lugares que han servido de refugio a los murciélagos. En el presente trabajo se presentan 2 brotes ocupacionales de histoplasmosis ocurridos en la provincia La Habana. MÉTODOS: se estudiaron 116 trabajadores que realizaron actividades generadoras de aerosoles en cuevas. Se efectuaron exámenes micológicos y serológicos a partir de muestras de los pacientes. Se recogieron muestras del suelo de las cuevas para determinar la presencia del agente causal. Se recolectaron datos clínico-epidemiológicos para la caracterización de los brotes. RESULTADOS: las tasas de ataque en ambos brotes fueron de 60 y 78 por ciento. La edad de los pacientes osciló entre 16 y 64 años; las principales manifestaciones clínicas (fiebre, malestar general, tos seca, cefalea, pérdida de peso y dolor torácico) comenzaron a aparecer entre los 10 y 20 d. Se realizó el diagnóstico microbiológico y serológico de histoplasmosis y se confirmó la fuente de infección mediante el aislamiento de H. capsulatum en los sitios donde se habían llevado a cabo intensos trabajos de excavación, con formación de abundantes aerosoles por períodos de hasta 21 d. Los 2 brotes estudiados tuvieron en común la realización de actividades generadoras de aerosoles en lugares de riesgo, sin la utilización de medios de protección. CONCLUSIONES: se hace necesaria la divulgación de las medidas preventivas entre el personal de salud y los grupos de riesgo, así como en la población en general para evitar y controlar futuros brotes de histoplasmosis.

INTRODUCTION: histoplasmosis, an infection caused by Histoplasma capsulatum fungus, is considered as one of the main endemic infections in the American continent where there are frequent epidemic outbreaks. Most of the outbreaks have been associated to risky activities in bat-inhabited places. This paper presented two outbreaks of occupational acquired histoplasmosis occurred in La Habana province. METHODS: one hundred and sixteen workers, who performed aerosol-generating tasks in caves, were studied. Samples from the cave soils were taken to assess the existence of the causal agent. Clinical and epidemiological data were gathered for the outbreak characterization. RESULTS: the rates of infection for both outbreaks were 60 percent and 78 percent respectively. The patients aged 16 to 64 years; additionally, the onset of main clinical manifestations (fever, general malaise, cough, headache, loss of weight, and chest pain) ranged from 10 to 20 days. Histoplasmosis was microbiologically and serologically diagnosed whereas its source of infection was confirmed through H. capsulatum isolation in those places where extensive excavation work had been carried out, resulting in abundant aerosols for up to 21d periods. The similarity between the two outbreaks was the performance of aerosol-generating tasks in risky places without using appropriate safety devices. CONCLUSIONS: It is necessary to disseminate the existing preventive measures among the health care staff and the risky groups as well as the general population in order to prevent and take control of possible histoplasmosis outbreaks in the future.

The epidemiology of fungaemia at the University Hospital of the West Indies, Kingston, Jamaica / Epidemiología de la fungemia en la Hospital Universitario de West Indies, Kingston, Jamaica

OBJECTIVES: To determine the epidemiology of fungaemia at the University Hospital of the West Indies (UHWI) as well as the incidence of fungaemia at the UHWI over a four-year period. METHODS: A cross-sectional survey was conducted over a one-year period (2002). The RapID Yeast Plus Panel Identification kit was used to identify the yeasts found in blood while morphology and dimorphism were used to identify the single mold isolated, Histoplasma capsulatum. In addition, a retrospective review of the number of cases of fungaemia at the UHWI over a four-year period from 1998 was done using the laboratory and clinical records in order to determine the incidence over this period. RESULTS: The study showed that Yeast not C albicans (YNCA) accounted for 47% of the isolates while Candida albicans accounted for 29%. Of the YNCA species, Candida tropicalis was the most common (75%), followed by C pseudotropicalis (12.5%) and C glabrata (12.5%). Cryptococcus sp accounted for 18% of all fungal isolates and there was one isolate (6%) of Histoplasma capsulatum. The medical wards had the most isolates (47%), followed by surgery (29%) and the Intensive Care Unit (ICU) [24%]. While the rate at which fungi were isolated from the blood remained constant over 1998, 1999 and 2001, this doubled in 2002 from 0.26% to 0.5%. CONCLUSION: Although the incidence of fungaemia at the UHWI has remained relatively low, there was a marked increase in the last year of the study (2002) with a doubling of the number of positive fungal cultures. Candida species account for most cases of fungaemia at the UHWI. However, non-albicans Candida spp were more commonly isolated than C albicans, a trend that needs to be monitored because of its implications for therapy.

OBJETIVOS: Determinar la epidemiología de la fungemia en el Hospital Universitario de West Indies (UHWI) así como la incidencia de la fungemia en UHWI durante un período de cuatro años. MÉTODOS: Se llevó a cabo un estudio transversal por espacio de un año (2002). Se utilizó un kit de paneles para la identificación rápida de levaduras (Rapid Yeast Plus Panel), con el propósito de identificar las levaduras halladas en la sangre, en tanto que la morfología y el dimorfismo fueron usados a fin de identificar los aislados del moho individual, Histoplasma capsulatum. Además, se realizó un examen retrospectivo del número de casos de fungemia en el UHWI por espacio de cuatro años desde 1998, usando las historias clínicas e informes de laboratorio, a fin de determinar la incidencia en este período. RESULTADOS: El estudio mostró que las levaduras no C albicans (LNCA) representaban el 47% de los aislados, mientras que la Candida albicans representaba el 29%. De las especie LNCA, Candida tropicalis fue la más común (75%), seguida de C pseudotropicalis (12.5%) y C glabrata (12.5%). Cryptococcus sp representaba el 18% de todos los aislados fúngicos, y hubo un aislado (6%) de Histoplasma capsulatum. Las salas de hospitales fueron las que más aislados presentaron (47%), seguidas por las Unidades de cirugía (29%) y las de Cuidados Intensivos (UCI) (24%). Si bien el ritmo al cual los hongos fueron aislados de la sangre permaneció constante durante 1998, 1999, y 2001, el mismo se duplicó en el año 2002 pasando de 0.26% a 0.5%. CONCLUSIÓN: Aunque la incidencia de la fungemia en el UHWI ha permanecido relativamente baja, se produjo un marcado aumento en el último año de estudio (2002), en el que se duplicó el número de cultivos fúngicos positivos. Las especies de Candida son responsables de la mayor parte de los casos de fungemia en el UHWI. Sin embargo, las especies Candida no albicans fueron más comúnmente aisladas que las C albicans - una tendencia que necesita ser monitoreada debido a sus implicaciones para la terapia.

Epidemiological study of paracoccidioidomycosis and histoplasmosis in a suburb of San Félix city Bolívar state Venezuela

Epidemiologic studies of deep mycosis have been scarce in Bolívar state, where paracoccidioidomycosis and histoplasmosis are considered as endemic diseases. The aim of this study was to determine paracoccidioidomycosis and histoplasmosis prevalences in people from a suburb of San Félix, Bolívar state, Venezuela. Three-hundred volunteers agreed to participate in this study and they were inoculated with paracoccidioidine and histoplasmine. Identification and epidemiologic data were registered. Reading of skin tests after 24 hours was performed in 275 persons. Paracoccidioidine test was positive in 10.2% (n=28). A higher percentage of positive reactions in the age group of 40-50 years old (n=10; 35.7%) was observed. Bricklayers, farmers and miners were positive in 27.3% (3 out of 11), a higher percentage than in people with other occupations. Histoplasmine test was positive in 7.6 percent of cases (n= 21). The higher percentage of reactivity was observed in the age group of 40-50 years old (n=9; 42.9%). There was a direct proportional relationship between staying time in the locality and H. capsulatum infection mainly in persons staying in the area for more than 30 years (p<0.05). These results showed low prevalences of P. brasiliensis and H. capsulatum infection in this area.

El estudio epidemiológico de las micosis profundas ha sido escaso en el estado Bolívar donde la paracoccidioidomicosis e histoplasmosis son endémicas. El objetivo de este estudio fue determinar la prevalencia de infecciones por Paracoccidioides brasiliensis e Histoplasma capsulatum en individuos residenciados en una población suburbana de San Félix, estado Bolívar, Venezuela. Se administró paracoccidioidina e histoplasmina a 300 personas voluntarias. Se realizó lectura de las pruebas a las 24 horas. La paracoccidioidina fue positiva en el 10,2% (n=28). Se observó mayor porcentaje de positividad en el grupo de 40-50 años (n=10; 35,7%). Las ocupaciones de riesgo: albañiles, agricultores y mineros, presentaron un porcentaje de positividad de 27,3% (3 de 11), mayor que el de los individuos sin riesgo aparente: mecánicos, oficios del hogar y estudiantes (25 de 264; 9,5 %) (p=0,04). La histoplasmina fue positiva en el 7,6% (n=21). El mayor porcentaje de intradermorreacción positiva se observó entre los 40-50 años (n=9; 42,9%). Hubo relación significativa entre el tiempo de residencia en la localidad y la infección por H. capsulatum, demostrándose en los individuos con más de 30 años en esa localidad (p<0,05). Estos resultados muestran una prevalencia relativamente baja de infecciones por P. brasiliensis y de H. capsulatum en el área estudiada.

Histoplasmose: [revisão] / Histoplasmosis: [review]

A histoplasmose é uma micose causada por fungo dimórfico, o Histoplasma capsulatum. É considerada classicamente uma micose endêmica, embora o fungo tenha um comportamento oportunístico em pacientes com depressão da imunidade celular. O homem adquire a infecção através da inalação de conídeos presentes na natureza (cavernas com morcegos, galinheiros, etc). O quadro clínico pode variar, desde infecções assintomáticas até quadros graves disseminados, que acometem pacientes com Aids, transplantados ou com neoplasias hematológicas. O diagnóstico baseia-se no encontro do fungo em fluidos orgânicos (escarro, sangue, líquor) ou tecidos (histopatologia), na cultura de materiais biológicos e na sorologia. O tratamento das formas agudas graves, respiratória crônica ou de formas localizadas pode ser feito com azólicos orais (itraconazol) e nas disseminadas, a Anfotericina B (preferencialmente as formulações lipídicas) constitui a droga da eleição para iniciar a terapia. A histoplasmose representa, hoje uma das micoses sistêmicas mais importantes nas Américas, com ampla distribuição em todas as regiões do Brasil.

Histoplasmosis is a fungal infection caused by the dimorphic fungus Histoplasma capsulatum. It is classically considered an endemic mycosis, even though the fungus has an opportunistic behavior in immunocompromised patients. People acquired the infection through the inhalation of conidial forms present in the environmental, such as caves dwelling bats and soils inhabited by chickens. The clinical features may vary from asymptomatic infections to disseminated severe forms that affect patients with acquired immunodeficiency syndrome or hematological malignancies and allograft recipients. The diagnosis is based on the detection of the fungus in organic fluids (sputum, blood, liquor) or tissues (histopathological assays), in the culture of biological samples and serological assays. The treatment of severe chronic respiratory acute or localized forms can be performed with oral azolic (itraconazol) and in the disseminated forms, the amphotericin B (preferentially the lipidic formulations) consists in the elected drug to initiate the therapy. Nowadays, histoplasmosis represents one of the most important systemic mycosis in the Americas, with broad distribution in all regions of Brazil.

Diagnóstico molecular de histoplasmosis humana en muestras de sangre entera / Molecular diagnosis of human histoplasmosis in whole blood samples

Se evaluó el uso de sangre entera para el diagnóstico molecular de histoplasmosis utilizando un método artesanal de extracción de ADN fúngico y una PCR anidada que amplifica una porción del gen HcP100 específica de Histoplasma capsulatum. La sangre entera se trató con liticasa, enzima lisante de Trichoderma harzianum y proteinasa K, seguido de una extracción fenólica. Este tratamiento permitió una lisis completa de las células, mostró buen rendimiento en la obtención de ADN y posibilitó la detección de la banda de 210 pb específica de H. capsulatum en la PCR anidada. El límite de detección fue de 0,25-1 levaduras/ml de sangre. El método se evaluó en 31 muestras de sangre de 19 pacientes con diagnóstico microbiológico de histoplasmosis, en 21 muestras de pacientes con otras micosis o infecciones por micobacterias y en 30 controles sanos. La PCR fue positiva en sangre para 17/19 pacientes con histoplasmosis (14/15 inmunocomprometidos y 3/4 sin inmunocompromiso aparente). Las muestras de sangre de los 30 controles sanos y de 20 pacientes con otras patologías fueron negativas, sólo hubo un falso positivo correspondiente a un paciente con infección por Mycobacterium avium-intracellulare. El método presentó 89% de sensibilidad y 96% de especificidad para el diagnóstico de histoplasmosis en sangre entera.

To assess the value of using whole blood samples for the molecular diagnosis of histoplasmosis, we applied an in-house DNA extraction method and a nested PCR targeting a 210 bp specific segment of the Histoplasma capsulatum HcP100 gene. A whole blood volume of 2.5-3 milliliters was centrifuged and the cellular pellet was treated with Trichoderma harzianum lyticase and proteinase K prior to applying a conventional phenol DNA extraction. This procedure allowed complete cell lysis, high DNA yield and specific amplification. The PCR detection limit was 0.25-1 yeast cells/ml of blood sample. The method was assessed on 31 blood samples from 19 patients with microbiological diagnosis of histoplasmosis, 30 healthy persons and 21 patients with other mycoses or mycobacterial diseases. Positive results were obtained in samples from 17/19 patients with histoplasmosis (14/15 immunocompromised and 3/4 without known immunological disorder). Blood samples from the 30 healthy controls and 20 patients with other conditions proved negative; the only false positive result was obtained from a patient with Mycobacterium avium-intracellulare infection. With 89% sensitivity and 98% specificity, this molecular method for detection of the agent in blood shows promising for the rapid diagnosis of human histoplasmosis.