Influenza pandémica A (H1N1) 2009: epidemiología, características clínicas y diferencias con influenza estacional en Chile / Pandemic influenza A (H1N1) 2009: epidemiology, clinical features and differences with seasonal influenza in Chile

Pandemic influenza A (H1N1) 2009 raised questions regarding differences with seasonal influenza. Objectives: To describe the clinical features of pandemic influenza and compare them to seasonal influenza. Patients y Methods: A descriptive study that compared hospitalized adults was done between patients with confirmed pandemic inluenza in the Hospital Clínico Universidad Católica in Santiago, Chile, from May to July 2009 and 95 confirmed historic cases of seasonal influenza. Results: 54 patients with pandemic influenza were included, 51.9 percent were male, age of 52.8 ± 19.5 years old; 79.6 percent had chronic diseases; 16.7 percent were immunocompromised patients and 7.4 percent of pregnant women. 25.9 percent of the patients acquired the infection during the hospitalization. 31.5 percent were admitted to intermediate/intensive care units. Pneumonia was diagnosed in 37 percent, and the mortality rate was 3.7 percent. The comparison between pandemic and seasonal influenza showed less proportion of patient > 65 years of age (31.5 percent vs. 68 percent; p < 0.0001); double number of nosocomial acquisition and more cases of pneumonia and death. Conclusions: The pandemic inluenza infection affected younger people and was related with more nosocomial cases, pneumonia and mortality rates than seasonal inluenza.

La pandemia de inluenza A (H1N1) 2009 generó preguntas sobre sus diferencias con influenza estacional. Objetivos: Describir las características de influenza pandémica y comparar con influenza estacional. Pacientes y Métodos: Estudio descriptivo de casos confirmados de influenza pandémica en adultos internados en el Hospital Clínico de la Pontificia Universidad Católica entre mayo y julio de 2009, comparado con 95 casos históricos de influenza estacional. Resultados: 54 pacientes con influenza pandémica, 51,9 por ciento género masculino, edad 52,8 ± 19,5 años; 79,6 por ciento presentaban co-morbilidades; 16,7 por ciento inmunocomprometidos, 7,4 por ciento mujeres embarazadas, 25,9 por ciento de adquisición nosocomial, 31,5 por ciento requirió cuidados intensivos/intermedios. Se diagnosticó neumonía en 37 por ciento y la mortalidad global fue 3,7 por ciento. En la comparación con inluenza estacional, la pandémica afectó menos pacientes > de 65 años (31,5 vs 68 por ciento, p < 0,0001), dobló los casos con adquisición nosocomial y hubo más casos de neumonía y muertes. Conclusiones: La infección por inluenza pandémica afectó a un grupo de menor edad y generó mayor transmisión nosocomial, neumonía y muerte que la inluenza estacional.

Caracterización clínica y molecular de bacteriemias causadas por enterobacterias productoras de β -lactamasas de espectro extendido: 2004-2007 / Clinical and molecular characterization of ESBL-producing enterobacteria isolated from bacteremia in a university hospital

Introduction: Extended-spectrum-β-lactamases (ESBL) are plasmid-encoded enzymes that confer resistance to multiple antimicrobials. ESBL-producing enterobacteria that cause bacteremia limit therapeutic options and increase mortality. Objective: To perform a clinical and molecular description of bacteremia caused by ESBL-producing enterobacteria. Method: We retrospectively studied the cases of bacteremia due to ESBL-producing Escherichia coli, Klebsiella pneumoniae and Proteus spp in adults admitted to a university hospital during the years 2004-2007. We reviewed the clinical records and antimicrobial susceptibility patterns. Molecular typing was performed by polymerase chain reaction and study of clonality by pulsed-field electrophoresis. Results: We found a prevalence of 9.8 percent ESBL in enterobacteria causing bacteremia. Decreased susceptibility to quinolones and aminoglycosides was observed, without resistance to carbapenems. The predominant ESBL types were CTX-M (96 percent), TEM (62 percent) and GES (28 percent). 79 percent of the strains presented more than one type of ESBL. Clinical analysis revealed high prevalence of risk factors, previous use of antimicrobials and of invasive devices. There was no significant clonality. Conclusion: The presence of ESBLs in bloodstream infections is a clinical problem that must be considered when choosing empiric therapy.

Introducción: β-lactamasas de espectro extendido (BLEE) son enzimas plasmidiales que confieren resistencia a múltiples antimicrobianos. Las bacteriemias por enterobacterias productoras de BLEE restringen las opciones terapéuticas y aumentan la mortalidad. Objetivo: Realizar una descripción clínica y molecular de las bacteriemias causadas por enterobacterias productoras de BLEE. Método: Se estudiaron retrospectivamente los casos de bacteriemia por Escherichia coli, Klebsiella pneumoniae y Proteus spp. confirmadas para BLEE, en adultos ingresados en un hospital universitario durante los años 2004-2007. Se revisaron los registros clínicos y de susceptibilidad. Se realizó tipificación molecular por reacción de polimerasa en cadena y estudio de clonalidad por electroforesis de campo pulsado. Resultados: Se identificó una prevalencia de BLEE de 9,8 por ciento en enterobacterias causantes de bacteriemias. Se observó susceptibilidad disminuida a quinolonas y aminoglucósidos, sin resistencia a carbapenémicos. Los tipos de BLEE predominantes fueron CTX-M (96 por ciento), TEM (62 por ciento) y GES (28 por ciento). El 79 por ciento de las cepas presentó más de un tipo de BLEE. El análisis clínico reveló alta frecuencia de patologías de riesgo, uso previo de antimicrobianos y uso de dispositivos invasores. No se encontró clonalidad significativa. Conclusión: La presencia de BLEE en bacteriemias constituye un problema clínico que debe ser considerado al elegir la terapia empírica.

Etiología de la neumonía en pacientes chilenos infectados por el virus de la inmunodeficiencia humana / Etiology of pneumonia in Chilean HIV-infected adult patients

Objectives: To establish the etiology of pneumonia and to compare the yield of diagnostic techniques for diagnosis of Pneumocystis jiroveci and Mycobacterium tuberculosis infections in HIV-1-infected patients. Patients and Methods: Subjects underwent sputum induction and bronchoalveolar lavage (BAL). Gram, Ziehl-Neelsen, silver stain (SS) and immunofluorescense staining (IF) for P. jiroveci, fluorescent stain for mycobacteria, PCR for P. jiroveci andM. tuberculosis, aerobic, fungal and mycobacterial cultures, respiratory viruses and CMV cultures were performed on the sputum and BAL. IgM for Mycoplasma pneumoniae and Chlamydophyla pneumoniae, and Legionella pneumophila urinary antigen were also obtained. Results: Sixty patients were included. An etiologic diagnosis was made in 97 percent. Pneumocystisjiroveci was the most frequent etiology (58 percent) followed by Streptococcus pneumoniae (12 percent), and Mycobacterium avium complex (12 percent). Mycobacterium tuberculosis was found in 5 percent. Conclusions: The comparison of diagnostic methods for P. jiroveci showed a higher sensitivity of IF and SS in BAL than in sputum, however PCR was equally sensitive in both samples. With this approach a precise etiologic diagnosis was reached in the great majority of patients. The most common etiology was P. jiroveci. IF in BAL remains the gold standard for diagnosis of P. jiroveci pneumonia.

Objetivos: Establecer la etiología de la neumonía y comparar el rendimiento de diferentes técnicas para el diagnóstico de las infecciones por Pneumocystis jiroveci y Mycobacterium tuberculosis en pacientes con infección por virus de inmunodeficiencia humana (VIH). Material y Métodos: De cada paciente se obtuvo esputo inducido y se efectuó LBA. A las muestras obtenidas se les realizó tinciones de Gram, Ziehl-Neelsen, plata e inmunofluores-cencia (IF) para P. jiroveci y M. tuberculosis; reacción de polimerasa en cadena (RPC) para ambos microorganismos; cultivos aeróbicos, fúngicos, para micobacterias, virus respiratorios y citomegalovirus. También se realizó determinación de IgM de Mycoplasma pneumoniae y Chlamydophyla pneumoniae y antígeno urinario de Legionella pneumophila. Resultados: Se incluyeron 60 pacientes, lográndose diagnóstico etiológico en 97 por ciento de los casos. Pneumocystis jiroveci fue la etiología más frecuente (58 por ciento), seguida por Streptococcus pneumoniae (12 por ciento) y Mycobacterium avium complex (MAC) (12 por ciento). Mycobacterium tuberculosis fue encontrado en 5 por ciento. Conclusiones: La comparación de los métodos diagnósticos para P. jiroveci mostró una mayor sensibilidad de la IF y tinción de plata en LBA que en esputo; sin embargo, la RPC fue igualmente sensible en ambos tipos de muestras. Con esta estrategia se logró establecer etiología en la gran mayoría de los pacientes. La etiología más común fue P. jiroveci. IF en LBA sigue siendo el estándar para el diagnóstico de la neumonía por P. jiroveci.

Perfil epidemiológico de la candidiasis invasora en unidades de pacientes críticos en un hospital universitario / Epidemiologial profile of invasive candidiasis in intensive care units at a university hospital

Invasive candidiasis (IC) epidemiology has changed in critically ill patients and limited data are available in Chile. Objective: To describe the epidemiological and microbiological profile of IC in critically ill patients. Methods: Observational prospective study conducted from October 2001 to August 2003 in critically ill adults with suspected or confirmed IC. Results: 53 patients met criteria for IC, finding 18 (33.9 percent) candidemias, 22 (41.5 percent) disseminated IC, and 13 (24.5 percent) local IC. We identified 8 (44.4 percent) C. albicans and 10 (55.6 percent) non-albicans Candida in candidemias. C. tropicalis was the predominant non-albicans species (27.7 percent). An 88.8 percent of Candidas sp recovered in candidemias were fluconazole susceptible. Overall hospital mortality was 24.5 percent. Mortality in candidemia was significantly lower than in disseminated IC (16.6 vs 31.8 percent, p = 0.02). Conclusions: A higher proportion of non-albicans Candida was observed in candidemias from critically ill patients. However, most of these strains were fluconazole susceptible. A lower overall mortality was observed in candidemias.

La epidemiología de candidiasis invasora (CI) ha cambiado, lo cual no ha sido suficientemente estudiado en Chile. Objetivo: Describir el perfil epidemiológico y microbiológico de CI en pacientes críticos. Métodos: Estudio observacional prospectivo entre octubre 2001 y agosto 2003, en pacientes críticos adultos con sospecha o confimnación de CI. Resultados: 53 pacientes cumplieron criterios de CI. De ellos, 18 (33,9 por ciento) tuvieron candidemia, 22(41,5 por ciento) CI diseminada y 13(24,5 por ciento) CI local. Entre las candidemias, hubo 8 C. albicans (44,4 por ciento) y 10 Candida no albicans (55,6 por ciento), predominando C. tropicalis (27,7 por ciento). Un 88,8 por ciento de las candidemias fueron susceptibles a fluconazol. La mortalidad hospitalaria global fue 24,5 por ciento, significativamente menor en pacientes con candidemias vs CI diseminada (16,6 vs 31,8 por ciento, p = 0,02). Conclusiones: Se observó una mayor proporción de Candida no albicans en candidemias de pacientes críticos. Sin embargo, la mayoría de estas cepas fue susceptible a fluconazol. La mortalidad global fue menor en candidemias.

Coinfecciones por virus hepatitis B, virus hepatitis C, Treponema pallidum y Toxoplasma gondii en la cohorte de pacientes VIH positivos en control en la Pontificia Universidad Católica de Chile / Hepatitis B, C, Treponema pallidum and Toxoplasma gondii co-infections in HIV infected patients

Background: Some infections share common modes of transmission with HIV and have the potential to change the course of the latter. Aim: To assess the prevalence of hepatitis B virus (HBV) hepatitis C virus (HCV), Treponema palladium and Toxoplasmosis gondii co-infections in HIV-1 infected patients followed at a university hospital. Material and methods: Clinical records of HIV-positive individuals were reviewed. The analysis included: demographical data, hepatitis B surface antigen (HBsAg), IgM and IgG anti-HBc, antibodies, anti-HCV antibodies, RPR or VDRL test and IgG anti Tgondii antibodies. Results: Three hundred ninety five patients (aged 16 to 89years, 359 males) were included in the review. Seventy nine percent had been tested for HBV status with HBsAg, and the global HIV-HBV co-infection prevalence was 6.1 percent. A subgroup of190 individuals were tested for HBV infection with HBsAg and IgM/IgG anti-HBc markers. Of these, 46 percent fulfilled co-infection criteria: eight with acute hepatitis B, 11 with chronic hepatitis B and 69 with inactive HBV infection. The frequency of HIV-HBV co-infection was 48 percent and 22 percent among men and women respectively (NS). HCV-HN co-infection was detected in 3 percent, syphilis-HIV co-infection in 21 percent and T gondii-HIV co-infection in 26 percent. Conclusions: In this cohort, HIV infection is accompanied by a high prevalence of other co-infections, particularly HBV among men.

Presencia de metalo-ß-lactamasas en Pseudomonas aeruginosa resistente a imipenem / Presence of metal lo ß-lactamases in imipenem-resistant Pseudomonas aeruginosa

Background: Metallo-ß-lactamases (MBL) confer high resistance to carbapenems in Pseudomonas aeruginosa (Psae). They are encoded in mobile elements of different genes (VIM, IMP, SMP, GIM), along with other resistance genes. Aim: To detect the presence of MBL in imipenem resistant Psae strains. Material and methods: Fifty-nine imipenem resistant Psae strains isolated from January 2004 to August 2005 in a University Clinical Hospital, were included. The presence of MBL was studied by Etest (phenotypic) and genotypic polymerase chain reaction (PCR) methods. To rule out a nosocomial outbreak, MBL positive strains, were studied by pulse field gel electrophoresis. Results: The presente of MBL was detected in eleven strains. AH were type VIM and were not clonally related. There was no concordance between phenotypic and genotypic MBL detecting methods. AH the strains were also multiresistant. Conclusions: The presence of MBL was detected in 19 percent of imipenem resistant Psae strains.

Amigdalitis aguda recurrente bacteriana: estudio prospectivo, comparativo y controlado de sus características clínicas y microbiológicas / Acute recurrent bacterial tonsillitis: prospective, comparative and controlled study of its clinical and microbiological characterisitics

Introducción: La amigdalitis aguda recurrente es una patología de frecuente consulta, es una de las indicaciones de amigdalectomía. No se sabe con exactitud el origen de esta patología. Objetivo: Identificar la microbiología y patrones de susceptibilidad de las bacterias en la amigdalitis aguda recurrente bacteriana (AARB) a los antimicrobianos más comúnmente en el medio nacional, usados en su tratamiento. Material y método: Se planificó un estudio prospectivo, controlado y ciego. Se evaluaron pacientes (casos) con antecedentes de AARB con indicación quirúrgica. Los criterios de inclusión de los casos fueron niños de ambos sexos entre 4 y 10 años, sin historia de inmunodeficiencias, no haber recibido antibióticos en los 15 días previos a la cirugía. Se definió como controles a los pacientes con antecedentes de apnea del sueño con indicación quirúrgica y sin antecedentes de AARB o cuadros sugerentes de amigdalitis en los últimos 6 meses. En todos los pacientes se utilizó la misma técnica de toma de muestra de tejido para cultivo y antibiograma. Para el estudio de sensibilidades se realizó un antibiograma de las cepas aisladas y se evaluó la presencia de beta lactamasas. Los datos fueron analizados con el programa S-plus para análisis univariado. Para evaluar proporciones se utilizó el test de chi-cuadrado o el test exacto de Fisher Las variables continuas fueron evaluadas con el test de Wilcoxon Two sample. Resultados: No se encontraron diferencias estadísticamente significativas entre las cepas encontradas en el grupo de casos y de controles. La bacteria aislada con más frecuencia fue Haemophilus influenzae en 26 muestras en cada grupo (81 por ciento), seguido por S. Aureusy Streptococccus beta hemolítico grupo A (SBHGA). En cuanto a las asociaciones de patógenos más frecuentes, se encontró que las mayores asociaciones fueron H. influenzae + S. aureusyH. influenzae + SBHGA. Tampoco hubo diferencias esrtadísticamente significativas en frecuencia de estas...

Malaria: revisión retrospectiva de 12 casos no autóctonos en Chile / Malaria: Report of 12 non autochthonous cases

Malaria is a protozoan infection caused by four Plasmodia species transmitted by female Anopheles mosquito. Nearly 40% of the world population is at risk of acquiring the disease because of increasing resistance to treatment, climate changes and travels to endemic zones. We report twelve patients with diagnosis of malaria, supported by the identification of parasites on blood smear. All cases had traveled to endemic zones (Peru, Ecuador, Central America, Africa), but only three used chemoprophylaxis. Seven cases were infected with Plasmodium vivax and five cases with P. falciparum. Three of latter required intensive care. All patients were treated with standard drugs according to the severity and Plasmodium specie, with excellent results and no mortality.

Tratamiento de la neumonía del adulto adquirida en la comunidad / Treatment of community-acquired pneumonia in adults

Appropriate antibiotic treatment reduces the duration of symptoms associated to pneumonia, the risk of complications and mortality. In most cases, it is not possible to identify the etiologic agent so antibiotic treatment is empirically prescribed. In Chile, one third of Streptococcus pneumoniae strain isolates has diminished susceptibility to penicillin; in-vitro erythromycin resistance is about 10-15% and cefotaxime resistance 2-10%. It is recommended to classify patients with community acquired pneumonia in four risk categories: Group 1: patients under 65 years without co-morbidities, in ambulatory attendance. Treatment: oral amoxicillin 1 g TID, 7 days. Group 2: patients over 65 years and / or co-morbidities, in ambulatory attendance. Treatment: oral amoxicillin/clavulanate 500/125 mg TID or 875/125 mg BID, or cefuroxime 500 mg BID, 7 days. Group 3: patients admitted to general wards with criteria of moderate severity. Treatment: ceftriaxone 1-2 g once a day or cefotaxime 1 g TID, IV, 7-10 days. Group 4: patients with severe CAP that must be interned into ICU. Treatment: ceftriaxone 2 g once a day or cefotaxime 1 g TID, IV, associated to erythromycin 500 QID, levofloxacin 500-1.000 mg once a day, or moxifloxacin 400 mg/once a day, IV, 10-14 days. In the presence of allergy to or treatment failure with betalactam drugs and/or positive serology for Mycoplasma, Chlamydia or Legionella sp it is recommended to add: erythromycin 500 mg QID, IV or oral, oral clarithromycin 500 mg BID, or oral azythromycin 500 mg once a day.

El tratamiento antimicrobiano apropiado reduce la duración de la sintomatología asociada a la neumonía, el riesgo de complicaciones y la mortalidad. En la mayoría de los casos, no es posible identificar el agente microbiológico que ocasiona la infección y por esto el tratamiento antibacteriano se prescribe en forma empírica. En Chile, un tercio de las cepas de Streptococcus pneumoniae muestra susceptibilidad disminuida a penicilina; mientras que la resistencia a eritromicina fluctúa entre 10-15% y a cefotaxima entre 2-10%. Se recomienda clasificar a los pacientes con neumonía comunitaria en cuatro categorías de riesgo: Grupo 1: pacientes bajo 65 años de edad, sin comorbilidad de manejo ambulatorio. Tratamiento: amoxicilina 1 gramo cada 8 horas vía oral durante 7 días. Grupo 2: pacientes sobre 65 años de edad y/o con comorbilidad de manejo ambulatorio. Tratamiento: amoxicilina/ácido clavulánico 500/125 mg cada 8 horas ó 875/125 mg cada 12 horas, o cefuroxima 500 mg cada 12 horas vía oral durante 7 días. Grupo 3: pacientes hospitalizados en sala de cuidados generales que tienen criterios de gravedad moderada. Tratamiento: ceftriaxona 1-2 g/día o cefotaxima 1 g cada 8 horas EV durante 7-10 días. Grupo 4: pacientes con neumonía comunitaria grave que deben ser manejados en la UCI. Tratamiento: ceftriaxona 2 g/día o cefotaxima 1 g cada 8 horas EV asociado a eritromicina 500 mg cada 6 h, levofloxacina 500-1.000 mg/día, o moxifloxacina 400 mg/día EV durante 10-14 días. En presencia de alergia o fracaso de tratamiento con agentes b-lactámicos y/o serología positiva para Mycoplasma, Chlamydia o Legionella sp se recomienda agregar: eritromicina 500 mg cada 6 h EV o VO, claritromicina 500 mg cada 12 h VO, o azitromicina 500 mg/día VO.

Cirugía valvular reparadora en endocarditis infecciosa / Valve repair surgery in infectious endocarditis

Background: Valve replacement has been the treatment of choice for patients with valvular complications of infectious endocarditis (IE). However, excellent results with valve repair allowed it to become a new therapeutic alternative for these patients. Aim: To evaluate the results of valve repair in patients with valvular complications of IE. Patients and Methods: From January 1991 to December 2000, 14 patients with valvular complications of IE underwent valve repair. Mean age was 37.9 ± 14.9. Results: New York Heart Association (NYHA) class was 2.8 ± 0.9. IE was located in the aortic in 6 (42 percent), in the mitral valve in 4 (29 percent) and in both valves in 4 cases (29 percent). Surgical indication was hemodynamic in 50 percent of the cases, echocardiographic in 29 percent and septic in 21 percent. Five aortic valves were bicuspid, 3 mitral valves were myxomatous and the rest were normal. The most common septic lesions were vegetations and leaflet perforations. A total of 23 aortic and 21 mitral valve repair procedures were performed. There were no deaths. Only 1 patient had a surgical complication (renal failure and prolonged mechanical ventilation). Follow-up was 100 percent complete. There was not late mortality. One patient with bone marrow aplasia required reoperation for a new episode of IE 19 months later. At the end of the follow-up NYHA class was 1.3 ± 0.6 and echocardiography showed a mild or absence of valve regurgitation in most patients. Conclusions: Valve repair surgery in IE has good results, with advantages over valve replacement (Rev MÚd Chile 2004; 132: 307-15).

Reconocimiento de influenza-A como etiología de síndrome febril e insuficiencia respiratoria en adultos hospitalizados durante brote en la comunidad / Influenza-A as etiology of fever and respiratory insufficiency in adults hospitalized during an outbreak in Chile

Background : Influenza-A (IA) occurs every winter, is mostly observed among outpatients. Aim: To describe the clinical and epidemiological characteristics of cases that required hospital admission during an outbreak in Chile in 1999. Patients and methods: Adults subjects, with Influenza A confirmed by antigen detection test, hospitalized in the clinical hospital of the ½Hospital ClÝnico de la Universidad Católica de Chile¼ between May and June, with fever or respiratory symptoms were studied. A special record was designed to register clinical, microbiological and therapeutic data. Results: Fifty five cases, 26 males, aged 15 to 91 years, were studied. Eighty four percent had chronic concomitant diseases and 9.1 percent were immunosuppressed. Clinical findings were fever in 87.3 percent, asthenia in 83.6 percent, cough in 93.6 percent, abnormal pulmonary signs in 69 percent, an elevated C-reactive protein (mean value of 11.6 ± 7.1 mg/dL) and acute respiratory insufficiency in 54.5 percent. Cases were isolated in cohort or individual rooms and 38.2 percent were admitted to intensive or intermediate care units. Amantadine was prescribed to 52 patients and was well tolerated. Thirty three percent of cases developed pneumonia. These subjects were older, had more dyspnea and respiratory insufficiency than patients without pneumonia. Conclusions: IA should be borne in mind when dealing with hospitalized adults, during epidemic outbreaks in the community. The clinical picture can resemble a serious bacterial infection. An early diagnosis allows the use of specific treatments, to decrease the risk of nosocomial spread and to avoid unnecessary use of antibiotics (Rev MÚd Chile 2004; 132: 317-24).

Neumonía por virus parainfluenza 3 en paciente inmunocomprometido / Parainfluenza 3 pneumonia in an immunocompromised patient

Un paciente de 45 años bajo tratamiento corticoidal por una probable sarcoidosis y una pancitopenia moderada ingresa por una neumonía que no responde a antibióticos ni a tratamiento antimicótico indicado a raíz del aislamiento de Aspergillus fumigatus en expectoración. Desarrolla una insuficiencia respiratoria progresiva e hipotensión y una inmunofluorescencia para virus parainfluenza 3 resulta positiva. Fallece al séptimo día y la necropsia muestra una neumonía necrotizante, daño alveolar difuso y abundantes partículas virales.

Diagnóstico de diarrea por clostridium difficile: en busca de un enfoque clínico más eficiente / Clinical diagnosis of clostridium difficile diarrhea: searching a more efficient clinical view

Background: The clinical parameters for the suspicion of Clostridium difficile infections, namely the use of antimicrobials and diarrhea, have a low predictive value for the diagnosis. Aim: To search other clinical variables and determine a clinical prediction model for (Clostridium difficile diarrhea. Patients and methods: All patients to whom a Clostridium difficile study was requested, were prospectively studied during 5 months. Clinical variables of these patients were registered. The diagnosis of Clostridium difficile was done using the cytotoxicity test in fibroblast cultures. Results: Ninety two patients were analyzed and in 26, the diagnosis of Clostridium difficile was confirmed. A logistic regression model disclosed an age over 60 years old, the presence of mucus in the stools and a temperature over 37.8 ­C in the previous 24 h, as significant predictors of the infection. The correlation of the model, between the predicted probability and the observed condition, was 81.5 per cent. Conclusions: The presence of the clinical variables identified in this study are associated with a high probability of an infection by Clostridium difficile in patients with diarrhea and the recent use of antimicrobials

Infección de prótesis de aorta ascendente: tratamiento con aseo quirúrgico, preservación de prótesis y transposición de colgajo muscular en dos casos / Infection of ascending aortic graft: treatment with surgical cleaning, graft preservation and transposition of muscle flaps, report of 2 cases

Mediastinitis with graft infection is a serious complication of ascending aorta replacement. We report two cases of graft infection, treated with surgical cleaning, graft preservation and transposition of muscle flaps. A 62 years old male was admitted 34 days after an ascending aortic grafting due to a sternal dehiscence and mediastinitis. Antimicrobial treatment was started and a surgical cleaning performed, leaving an open sternotomy. Three days later, the thoracic cavity was closed with a rectus abdominis muscle flap. After 23 months of follow up, the patient is well and without evidence of infection. A 74 years old male was subjected to an aortic valve and ascending aorta replacement and a myocardial revascularization. In the postoperative period, the patient developed septic signs, and a purulent drainage. A CAT scan showed a liquid collection surrounding the aortic graft. On tW Sixteenth postoperative day, a surgical cleaning was performed and the thorax was closed with the pectoralis major muscle. After 10 months of follow up, the patient is in Good condition and without evidence of infection

Tratamiento de la neumonía asociada a ventilación mecánica / Treatment of pneumonia associated to mechanical ventilator

Ventilator-associated pneumonia is a life-threatening disease causing an increased morbidity, mortality, cost and length of stay in the intensive care unit. Inappropriate treatment is frequent and it is associated with worse prognosis. This document is an evidence based consensus which discusses treatment aspects of this complication. Empiric treatment should be based on local epidemiology and data collected through the national nosocomial infection surveillance and reliable microbiology. Antibiotic treatment on specific microorganisms is also recommended

Consideraciones generales sobre el uso de agentes antimicrobianos en pacientes hepáticos / General remarks: antimicrobial agents use in hepatic patients

El hígado juega un papel fundamental en el metabolismo de las drogas, incluyendo los antimicrobianos. En los pacientes con enfermedad hepática, se deben monitorizar cuidadosamente los efectos adversos y toxicidad de estos medicamentos. En este artículo se analizan los aspectos del metabolismo de los antimicrobianos, particularmente relacionados a los cambios farmacocinéticos en los pacientes hepáticos. Además, se dan algunas recomendaciones prácticas sobre su uso en estos pacientes