[Respiratory tract fluid microbiology in an intensive care unit]. / Microbiología de secreciones bronquiales en una unidad de cuidados intensivos.

OBJECTIVE: to know patterns of antimicrobial resistance of bacterial isolates from tracheal aspirates in an Intensive Care Unit and to evaluate the cases of ventilator-associated pneumonia. METHODS: antibiotic sensitivity test was done. A comparison was made between patients with nosocomial pneumonia reported by infection surveillance team against those reported by the attending physician with the infectious disease consultant. RESULTS: Pseudomonas aeruginosa was the bacteria most frequently reported with 134 isolates (26 %), 71 were multiple-drug-resistant; followed by Staphylococcus with 122 isolates (24 %), of which 88 were S. aureus with 62 of them (70 %) methicillin-resistant. Enterobacteriaceae, E. coli, K. pneumoniae, E. cloacae, S. marcescens, as well as Acinetobacter sp. and S. maltophilia were occasionally isolated. Candida represented 17 % of the isolates. Three peaks of isolates of S. aureus and P. aeruginosa were identified during the two years of surveillance. There were differences in cases of ventilator associated pneumonia reported by the hospital based epidemiology team and the attending clinicians in collaboration with an Infectious disease consultant. CONCLUSIONS: prevalence of multiple-drug-resistant Pseudomonas aeruginosa (53 %) and methicillin resistant Staphylococcus (70 %) isolated from the airway is high in our Intensive Care Unit. Enterobacterias, Acinetobacter sp. and Stenotrophomonas maltophilia colonization are low in our Intensive Care Unit.

[Cosyntropin test in severe active tuberculosis]. / Prueba de cosintropina en tuberculosis activa grave.

BACKGROUND: Frequency of adrenal insufficiency in patients with tuberculosis varies from 0 to 58%; however, all published series excluded severely ill patients. Our objective was to investigate adrenal insufficiency with the low-dose cosyntropin test in patients with severe active tuberculosis. METHOD: From two large university affiliated hospitals, 18 patients with tuberculosis and criteria of sepsis or severe sepsis according to SCCM/ACCP criteria, defined by the present authors as severe active tuberculosis, participated in the study. A low-dose ACTH test with 10 mg of ACTH was performed. After ACTH test, all patients received a stress dose of hydrocortisone (240 mg/day) during their entire hospitalization along with four antituberculous drugs. Abnormal response was considered when elevation of serum cortisol was <7 microg/dl with respect to basal level, 60 min after ACTH administration. RESULTS: Adrenal insufficiency was found in seven patients (39%); no clinical or laboratory data were associated with the presence of abnormal adrenal response. Except in one patient with HIV infection, all the signs and symptoms improved after antituberculous and hydrocortisone treatment. The increment in serum cortisol value post-ACTH test was lower in patients with hypoalbuminemia. CONCLUSIONS: Adrenal insufficiency is frequent in severe active tuberculosis. The efficacy and security of supplemental steroid treatment in severe active tuberculosis should be established by a randomized clinical trial.

Prueba de cosintropina en tuberculosis activa grave / Cosyntropin test in severe active tuberculosis

BACKGROUND: Frequency of adrenal insufficiency in patients with tuberculosis varies from 0 to 58%; however, all published series excluded severely ill patients. Our objective was to investigate adrenal insufficiency with the low-dose cosyntropin test in patients with severe active tuberculosis. METHOD: From two large university affiliated hospitals, 18 patients with tuberculosis and criteria of sepsis or severe sepsis according to SCCM/ACCP criteria, defined by the present authors as severe active tuberculosis, participated in the study. A low-dose ACTH test with 10 mg of ACTH was performed. After ACTH test, all patients received a stress dose of hydrocortisone (240 mg/day) during their entire hospitalization along with four antituberculous drugs. Abnormal response was considered when elevation of serum cortisol was <7 microg/dl with respect to basal level, 60 min after ACTH administration. RESULTS: Adrenal insufficiency was found in seven patients (39%); no clinical or laboratory data were associated with the presence of abnormal adrenal response. Except in one patient with HIV infection, all the signs and symptoms improved after antituberculous and hydrocortisone treatment. The increment in serum cortisol value post-ACTH test was lower in patients with hypoalbuminemia. CONCLUSIONS: Adrenal insufficiency is frequent in severe active tuberculosis. The efficacy and security of supplemental steroid treatment in severe active tuberculosis should be established by a randomized clinical trial.

Histoplasma capsulatum en sangre periférica de pacientes con SIDA: informe de cuarto casos con elevación de deshidrogenasa láctica / Histoplasmosis in peripheral blood smear of patients with AIDS: a report of four cases with serum lacte dehydrogenase elevated

Se describen los casos clínicos de cuatro pacientes con SIDA en quienes se hizo el diagnóstico de histoplasmosis al encontrar H. capsulatum en frote de sangre periférica. Todos los pacientes tuvieron evolución ffulminante de la infección y fallecieron durante los primeros cuatro días de hospitalización. En todos los casos de corroboró en cultivo la presencia de micelio y macroconidias "ornamentadas" característico de Histoplasma. Presentaron alteraciones hematológicas que son frecuentes en otras entidades asociadas a SIDA y, además, elevación importante de la enzima deshidrogenasa láctica sérica de más de diez veces el valor normal (menos de 221 Ul/mL): la cifra menor de DHL encontrada en estos pacientes fue de 2137 Ul/mL y la mayor de 4839 Ul/mL. Esta presentación que semeja septicemia y el hallazgo se sangre periférica de histoplasma, representan el 11.7 por ciento de los 34 pacientes con SIDA e histoplasmosis atendidos en el hospital de infectología del Centro Médico "La Raza".

No olvidar al tifo murino: informe de dos casos / Co not forget murine typhus: a report of two cases

El reconocimiento del tifo murino es importante desde el punto de vista epidemiológico, el diagnóstico diferencial es amplio y debe descartarse en los pacientes con infección del sistema reticuloendotelial. Se presentan dos casos clínicos de tifo murino: un hombre de 34 años de edad residente de la Ciudad de México, con historia de viajes a Morelia y Guadalajara, que desarrolló síndrome febril, con reacción febril positiva para Proteus OX-19 (1:160) y serología positiva por inmunofluorescencia (IFA) para Rickettsia typhi, IgM e igG a títulos mayores de 1:128. El segundo caso corresponde a una mujer de 22 años de edad, residente de la ciudad de Matamoros, Tamaulipas, con cuadro clínico compatible y reacción febril positiva para Proteus OX-19 a títulos de 1:320, sin realizarse IFA. Los dos pacientes se curaron, en el primer caso se administró cloramfenicol oral y en el segundo ciprofloxacina. Presentamos estos dos casos como refuerzo al llamado del Instituto Nacional de Diagnóstico y Referencia Epidemiológicos (INDRE) para considerar el diagnóstico de rickettsiosis en pacientes febriles de áreas endémicas en México. Creemos que estas afecciones están subdiagnosticadas en nuestro país

Comparación de dos tinciones en la detección de Pneumocystis carinii / Comparison of two staining methods in the detection of pneumocystis carinii

Evaluar dos metodologías para identificar P. carinii en lavado bronquio-alveolar. Material y métodos. Se obtuvo lavado bronquio-alveolar de 20 ratas a las que se indujo una infección de P. carinii por inmunosupresión. Las muestras se tiñieron con tres métodos: azul de toluidina modificada (ATM), Diff Quik (DQ), y tinción de plata como estándar de oro. Dos observadores hicieron la búsqueda de P. carinii en forma independiente. Resultados. La tinción de plata mostró P. carinii en 15 de las 20 muestras. Con DQ hubo una especificidad de 100 por ciento pero 27 por ciento de sensibilidad; con ATM la sensibilidad fue de 93 por ciento pero especificidad de 80 por ciento. La concordancia interobservadores (índice kappa) fue de 0.11 con DQ y de 0.53 con ATM. Conclusión. Nuestros resultados sugieren la conveniencia de usar la tinción de plata para garantizar los resultados en el diagnóstico de neumonía por P carinii