Pulmonary Histoplasmosis in a Referral Hospital in Mexico City.

Pulmonary histoplasmosis is caused by inhaling Histoplasma capsulatum. Less than 1% develops the disease. Risk factors in immunocompetent individuals are environmental exposures in endemic areas. The objective of this study is to determine the frequency, clinical, and microbiological characteristics in immunocompetent patients. A retrospective case series study of patients diagnosed with pulmonary histoplasmosis was performed in a respiratory care unit in Mexico City from 2000 to 2020. Each patient had bronchial lavage, and three patients underwent thoracoscopy for the lung tissue sample taken for the culture in Sabouraud Dextrose Agar. Twelve patients were identified, 8 males and 4 females; the predominant symptoms were fever (83%), dyspnea (75%), chest pain (66%), hemoptysis (41%), and weight loss (33%). The computed tomography of the chest showed the following findings: patchy consolidation 12 (100%), hilar adenopathy 6 (50%), pleural effusion 6 (50%), caverns 3 (25%), and solitary pulmonary nodule in one patient (8%). Histoplasma capsulatum was found in the culture of all twelve patients. The signs and symptoms of the disease are mediated by the immune status of the host. The clinical picture is often confused with systemic diseases. It is important to have a high degree of clinical suspicion to make a timely diagnosis.

Nontuberculous mycobacteria in cervical lymphadenopathies of HIV positive and HIV-negative adults / Micobacterias no tuberculosas en linfadenopatías cervicales de adultos VIH positivos y VIH negativos

Background: Tuberculosis is a global public health problem, especially in emerging countries. Mycobacterium tuberculosis is the main cause of cervical lymphadenopathy; nontuberculous mycobacteria are relatively common in children and rare in adults. Objective: To identify and establish the frequency of infectious etiology by nontuberculous mycobacteria in Mexican adult patients with cervical lymphadenopathy. Methods: The study included 85 patients over 18 years with cervical lymphadenopathy; 45 were HIV-positive, 40 were HIV-negative; they had no history of tuberculosis treatment and were selected from a third-level hospital. It was carried out a biopsy of the lymph node for the histopathological study, a search for acid-fast bacilli, a tube culture to indicate growth of Mycobacterium BACTEC (MGIT-960) and identification of mycobacterial strain by PCR-RFLP (restriction fragment length polymorfism) of hsp65. Results: In 42 HIV-positive patients (93%), strains corresponded to Mycobacterium tuberculosis complex, two (4.4%) to M. intracellulare and one (2.2%) to M. gordonae. Among HIV-negative patients, 39 of strains (97.5%) corresponded to patients with M. tuberculosis complex and one strain (2.5%) to M. fortuitum. Conclusion: The presence of nontuberculous mycobacteria was found in 4.7% of all cases. Despite this low frequency, it must be taken into account as a possible cause of lymphadenopathy, since its prompt identification enables introducing specific treatment.

Introducción: la tuberculosis es un problema de salud pública mundial, sobre todo en países emergentes. El Mycobacterium tuberculosis es el principal causante de las adenopatías cervicales; las micobacterias no tuberculosas son relativamente frecuentes en el niño y raras en adultos. Objetivo: identificar y establecer la frecuencia de la etiología infecciosa por micobacterias no tuberculosas (MNT) en pacientes adultos mexicanos con linfadenopatias cervicales. Métodos: se estudiaron 85 pacientes mayores de 18 años, con linfadenopatía cervical, 45 con positividad al virus de la inmunodeficiencia humana (VIH) y 40 VIH negativos, sin antecedentes de tratamiento antituberculoso, seleccionados en un hospital de concentración de especialidad de tercer nivel. Se realizó biopsia de nodo linfático para su estudio histopatológico, búsqueda de bacilos ácido-alcohol resistentes, cultivo en el tubo indicador del crecimiento de Mycobacterium BACTEC (MGIT-960) y la identificación de cepa micobacteriana por PCR-RFLP (restriction fragment lenght polymorfism) de hsp65. Resultados: las cepas correspondieron al complejo Mycobacterium tuberculosis en 42 pacientes VIH positivos (93%), dos (4.4%) a M. intracellulare y una (2.2%) a M. gordonae. Las cepas correspondieron al complejo M. tuberculosis en 39 pacientes VIH negativos (97.5%) y una a M. fortuitum (2.5%). Conclusión: la presencia de MNT se encontró en 4.7% de todos los casos. A pesar de su baja frecuencia, deben ser tomadas en cuenta como posible causa de linfadenopatías, porque su identificación oportuna permite instaurar un tratamiento específico.

Identification of risk factors and diagnostic methodology in serositis by M. tuberculosis / Identificación de factores de riesgo y metodología diagnóstica en serositis por M. tuberculosis

Background: Tuberculosis is a public health problem, extrapulmonary presentations have increased, it is difficult to diagnose because of the low bacillary load. Objective: To identify risk factors and to evaluate the efficiency of diagnostic methods in pleural, meningeal, peritoneal and pericardial tuberculosis. Methods: Prospective study of cases and controls. A multiple conditional logistic regression model was used to identify risk factors. Biopsy was performed and 7 mL of fluid was extracted from the affected site, Löwestein-Jensen and MGITI960 culture, Ziehl-Neelsen staining, adenosine deaminase and endpoint PCR directed to the insertion sequence 1S6110 for M. tuberculosis were performed. Results: 116 patients were included, in 58 M. tuberculosis was confirmed by positive culture (meningeal Tb 34 cases, pleural 14, peritoneal 8, pericardial 2 cases) and 58 serositis of non-tuberculous etiology. Being a carrier of HIV and living with people infected with tuberculosis were the main risk factors OR = 3.6 and OR = 6.8. The staining had sensitivity of 25.9%, PCR of 65.5% and adenosine deaminase with 82.8% Conclusions: Conventional diagnostic methods had low efficacy, adenosine deaminase and molecular biology techniques are the most useful, in our environment these tests should be performed immediately in patients with risk factors and suspected serositis of tuberculous origin.

Introducción: la tuberculosis es un problema de salud pública, las presentaciones extrapulmonares han aumentado, siendo de difícil diagnóstico por su baja carga bacilar. Objetivo: identificar los factores de riesgo y evaluar la eficacia de los métodos diagnósticos en la tuberculosis pleural, meníngea, peritoneal y pericárdica. Métodos: estudio prospectivo de casos y controles. Se empleó un modelo de regresión logística condicional múltiple para identificar factores de riesgo. Se realizó biopsia y se extrajeron siete mL de líquido presente del sitio afectado, se realizó cultivo Löwestein-Jensen y MGITI960, tinción Ziehl-Neelsen, adenosina deaminasa y PCR en punto final dirigida a la secuencia de inserción 1S6110 para M. tuberculosis. Resultados: se incluyeron 116 pacientes, en 58 se confirmó M. tuberculosis por cultivo positivo (Tb meníngea 34 casos, pleural 14, peritoneal 8, pericárdica 2 casos) y 58 serositis de etiología no tuberculosa. Ser portador de VIH y convivir con personas infectadas con tuberculosis fueron los mayores factores de riesgo OR = 3.6 y OR = 6.8. La tinción tuvo sensibilidad de 25.9%, PCR de 65.5% y adenosina deaminasa con 82.8%. Conclusiones: los métodos diagnósticos convencionales tuvieron baja eficacia, la adenosina deaminasa y las técnicas de biología molecular son los de mayor utilidad, en nuestro medio estos estudios deben realizarse de inmediato en pacientes con factores de riesgo y sospecha de serositis de origen tuberculoso.