Histoplasmose pulmonar aguda: relato de uma microepidemia

Acute pulmonary histoplasmosis: a case series from an outbreak in Southeastern Brazil

Histoplasmosis is a systemic mycosis prevalent in the Americas. Humans become infected via the respiratory route by inhaling aerosols from soil contaminated with bird and bat excretions. Acute pulmonary histoplasmosis is usually asymptomatic and is more often a self-limiting illness. We report a series of seven acute pulmonary cases in adults during an outbreak in Nova Friburgo city, Rio de Janeiro State, Brazil, in a group of volunteers who were cleaning an old, abandoned house without using personal protective equipment. The patients had a favorable evolution after suitable treatment, but all required hospitalization.

Histoplasmosis Outbreaks in Brazil: Lessons to Learn About Preventing Exposure

Histoplasmosis is considered the most common invasive opportunistic fungal disease in the Americas, with outbreaks and micro-epidemics reported for over 80 years. In Brazil, this disease has been described since 1946, reaching a remarkable incidence in the population, especially during the HIV-AIDS pandemic. In this study, published and unpublished outbreaks and micro-epidemics of histoplasmosis in Brazil were revisited by accessing different database sources and evaluating epidemiological and clinical features. We have found reports spanning 1946-2017, across 10 Brazilian states and with involvement of 370 humans and 2 dogs, and 13 disseminated cases and 3 deaths were reported. Rio de Janeiro had the largest number of outbreaks (n = 20/40; 50%) reported in this study. The majority of outbreaks and micro-epidemics was reported in caves (n = 21/40; 52.5%), followed by reports in abandoned/deactivated sites (n = 6/40; 15%), mines (n = 5/40; 12.5%), chicken coops (n = 4/40; 10%). Histoplasmosis is a serious health issue in Brazil considering the attractive and growing market of ecotourism throughout more than 7000 caves, and all levels of poultry farming activity are important to raise awareness about how dangerous this neglected disease can be and establish ways to decrease exposure to contaminated environmental sources through adequate preventive measures.

Histoplasma capsulatum-Induced Cytokine Secretion in Lung Epithelial Cells Is Dependent on Host Integrins, Src-Family Kinase Activation, and Membrane Raft Recruitment

Histoplasma capsulatum var. capsulatum is a dimorphic fungus that causes histoplasmosis, a human systemic mycosis with worldwide distribution. In the present work, we demonstrate that H. capsulatum yeasts are able to induce cytokine secretion by the human lung epithelial cell line A549 in integrin- and Src-family kinase (SFK)-dependent manners. This conclusion is supported by small interfering RNA (siRNA) directed to α3 and α5 integrins, and PP2, an inhibitor of SFK activation. siRNA and PP2 reduced IL-6 and IL-8 secretion in H. capsulatum-infected A549 cell cultures. In addition, α3 and α5 integrins from A549 cells were capable of associating with H. capsulatum yeasts, and this fungus promotes recruitment of these integrins and SFKs to A549 cell membrane rafts. Corroborating this finding, membrane raft disruption with the cholesterol-chelator methyl-β-cyclodextrin reduced the levels of integrins and SFKs in these cell membrane domains. Finally, pretreatment of A549 cells with the cholesterol-binding compound, and also a membrane raft disruptor, filipin, significantly reduced IL-6 and IL-8 levels in A549-H.capsulatum cultures. Taken together, these results indicate that H. capsulatum yeasts induce secretion of IL-6 and IL-8 in human lung epithelial cells by interacting with α3 and α5 integrins, recruiting these integrins to membrane rafts, and promoting SFK activation.

AN, Facanha MC, Leitao TDMJS. HISTOPLASMIN SURVEY IN HIV-POSITIVE PATIENTS: RESULTS FROM AN ENDEMIC AREA IN NORTHEASTERN BRAZIL

SUMMARY Background. Disseminated histoplasmosis is common in AIDS patients with advanced immunosuppression in Ceará, Northeastern Brazil. The goal of this study was to determine the prevalence of Histoplasma infection in patients with HIV/AIDS living in Fortaleza, the capital of Ceará. Methods. Intradermal tests with histoplasmin (mycelial phase) were performed in 161 HIV patients with CD4 ≥ 350 cells/mm 3 . Evidence of recent illness was evaluated with immunodiffusion (ID) tests in 76 of these individuals. Results. A total of 11.8% of patients reacted to histoplasmin and 2.63% had ID test positive to Histoplasma. The presence of mango trees (Mangifera indica) in the patient neighborhood (OR = 2.870; 95% CI = 1.081-7.617; p = 0.040) and past activity involving soil (OR = 2.834; 95% CI = 1.045-7.687; p = 0.045) or visits to a farm (OR = 3.869; 95% CI = 1.189-12.591; p = 0.033) were significantly associated with Histoplasma infection. Conclusions. Patients with HIV living in Fortaleza have an expressive prevalence of infection with Histoplasma.

Valor do FDG[18F]-PET/TC como preditor de câncer em nódulo pulmonar solitário

OBJETIVO: Determinar a acurácia diagnóstica da positron emission tomography (tomografia por emissão de pósitrons)/tomografia computadorizada (PET/TC) com deoxiglicose marcada com flúor-18, conhecida como fluorodeoxiglicose (FDG[18F]), na avaliação de nódulo pulmonar solitário (NPS). MÉTODOS: Análise prospectiva de 53 pacientes consecutivos que realizaram PET/TC para avaliação de NPS, entre março de 2005 e maio de 2007. Destes 32 preencheram os critérios de inclusão. As lesões foram avaliadas quanto a sua localização e tamanho, grau de captação do radiofármaco e o standardized uptake value (SUV, valor padronizado de captação) máximo das lesões. Os achados dos estudos de FDG-PET/TC foram correlacionados com outros preditores de malignidade (idade, sexo, tabagismo, tamanho e localização do nódulo). O diagnóstico definitivo foi estabelecido por confirmação histopatológica ou acompanhamento clínico-radiológico por um período mínimo de um ano. RESULTADOS: Encontrados 14 NPS malignos. Após análise da curva ROC, o SUV de 2,5 foi considerado o melhor ponto de corte que identificou corretamente 13 dos 14 NPS malignos. Os resultados abaixo deste ponto de corte mostraram um exame falso positivo para neoplasia num total de 14. O método semiquantitativo apresentou sensibilidade de 92,9%, especificidade de 72,2%, valor preditivo positivo de 72,2%, valor preditivo negativo de 92,9% e acurácia de 81,2%. Na análise multivariada, apenas a localização do nódulo nos lobos superiores (p = 0,048) e o SUV (p = 0,007) demonstraram significância estatística para malignidade no NPS. CONCLUSÕES: Os dados do estudo mostram que o SUV da FDG[18F] é um bom preditor de neoplasia em nódulos pulmonares e com alto valor preditivo negativo, o que oferece grande segurança em afastar presença de malignidade, indicando sua importância na abordagem diagnóstica do nódulo pulmonar.

Histoplasmose pulmonar aguda no Rio Grande do Sul

INTRODUÇÃO: A histoplasmose pulmonar aguda depende da inalação de uma grande quantidade de propágulos fúngicos por um paciente hígido. O tempo de exposição determina a gravidade da doença. Uma epidemia é influenciada por fatores que afetam o crescimento e a transmissão do Histoplasma capsulatum var. capsulatum na natureza. OBJETIVO: Identificar os aspectos epidemiológicos e clínico-laboratoriais dos pacientes com histoplasmose pulmonar aguda no Rio Grande do Sul e compará-los com as microepidemias relatadas no Brasil. MÉTODO: Foram revisados 212 prontuários clínicos de pacientes com histoplasmose dos arquivos do Laboratório de Micologia do Complexo Hospitalar Santa Casa de Porto Alegre (RS) num período de 25 anos (1977-2002). Foram identificados e incluídos no estudo os casos de histoplasmose pulmonar aguda com cultivo positivo e/ou achado histopatológico compatível. As microepidemias foram diagnosticadas com a comprovação de um caso ou evidência soromicológica com história clínica compatível. Foram revisadas as microepidemias publicadas no Brasil. RESULTADOS: Dezoito de um total de 212 pacientes (8,5%) foram incluídos no trabalho. A idade variou de 8 a 63 anos (média de 35,4; mediana de 34,5), e 67% eram do sexo masculino. A história epidemiológica foi sugestiva em 11 pacientes (61%). O tipo primário de histoplasmose pulmonar aguda foi o mais freqüente (17; 95%). Houve predomínio de casos isolados. CONCLUSÃO: O reconhecimento de casos isolados e a presença de microepidemias demonstram a abundância do H. capsulatum no solo, e juntamente com a ocorrência de todas as formas da doença, confirmam o Rio Grande do Sul como hiperendêmico para histoplasmose.