Mortality among critically ill patients with methicillin-resistant Staphylococcus aureus bacteremia: a multicenter cohort study in Colombia.

OBJECTIVE: To evaluate risk factors associated with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia emergence, its prognosis, and mortality-determining factors in critically ill patients in Colombia. METHODS: A multicenter, retrospective cohort study conducted in 2005-2008 at 16 public and private reference health care institutions in Bogotá, Colombia, that form part of a national epidemiological surveillance network and a hospital network with 4 469 beds. Methicillin-resistant emergence and mortality were analyzed using descriptive and time-to-event analysis; a multivariate Cox proportional hazard regression model was built to test the association between methicillin resistance and mortality. RESULTS: A total of 372 patients were studied: 186 with MRSA bacteremia, randomly matched with 186 with methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia. Previous surgery, antibiotic exposure, and hospital-acquired infections were independently associated with methicillin resistance. MRSA caused longer hospital stays among survivors (median 24 versus 18 days, P = 0.014). Mortality predictors were: patient age, creatinine level over 1.21 mg/dl at ICU admission, severe sepsis, and inotropic requirement. Appropriate antimicrobial therapy and antimicrobial therapy change were independent protective factors, as was male gender. CONCLUSIONS: Methicillin resistance per se was not a mortality-independent prognostic factor. Previous conditions, such as age, baseline renal impairment, severe sepsis, and inotropy demand explained the observed mortality. Appropriate antimicrobial therapy remained a protective factor. A call to improve infection control measures in Colombia is mandatory.

Device-associated infection rate and mortality in intensive care units of 9 Colombian hospitals: findings of the International Nosocomial Infection Control Consortium.

OBJECTIVE: To perform active targeted prospective surveillance to measure device-associated infection (DAI) rates, attributable mortality due to DAI, and the microbiological and antibiotic resistance profiles of infecting pathogens at 10 intensive care units (ICUs) in 9 hospitals in Colombia, all of which are members of the International Infection Control Consortium. METHODS: We conducted prospective surveillance of healthcare-associated infection in 9 hospitals by using the definitions of the US Centers for Disease Control and Prevention National Nosocomial Surveillance System (NNIS). DAI rates were calculated as the number of infections per 100 ICU patients and per 1,000 device-days. RESULTS: During the 3-year study, 2,172 patients hospitalized in an ICU for an aggregate duration of 14,603 days acquired 266 DAIs, for an overall DAI rate of 12.2%, or 18.2 DAIs per 1,000 patient-days. Central venous catheter (CVC)-related bloodstream infection (BSI) (47.4% of DAIs; 11.3 cases per 1,000 catheter-days) was the most common DAI, followed by ventilator-associated pneumonia (VAP) (32.3% of DAIs; 10.0 cases per 1,000 ventilator-days) and catheter-associated urinary tract infection (CAUTI) (20.3% of DAIs; 4.3 cases per 1,000 catheter-days). Overall, 65.4% of all Staphylococcus aureus infections were caused by methicillin-resistant strains; 40.0% of Enterobacteriaceae isolates were resistant to ceftriaxone and 28.3% were resistant to ceftazidime; and 40.0% of Pseudomonas aeruginosa isolates were resistant to fluoroquinolones, 50.0% were resistant to ceftazidime, 33.3% were resistant to piperacillin-tazobactam, and 19.0% were resistant to imipenem. The crude unadjusted attributable mortality was 16.9% among patients with VAP (relative risk [RR], 1.93; 95% confidence interval [CI], 1.24-3.00; P=.002); 18.5 among those with CVC-associated BSI (RR, 2.02; 95% CI, 1.42-2.87; P<.001); and 10.5% among those with CAUTI (RR, 1.58; 95% CI, 0.78-3.18; P=.19). CONCLUSION: The rates of DAI in the Colombian ICUs were lower than those published in some reports from other Latin American countries and were higher than those reported in US ICUs by the NNIS. These data show the need for more-effective infection control interventions in Colombia.

Mortality among critically ill patients with methicillin-resistant Staphylococcus aureus bacteremia: a multicenter cohort study in Colombia / Mortalidad en pacientes gravemente enfermos con bacteriemia por Staphylococcus aureus resistente a la meticilina:un estudio multicéntrico de cohortes en Colombia

Objetivo. Evaluar los factores de riesgo asociados con la aparición de bacteriemia por Staphylococcus aureus resistente a la meticilina (MRSA), su pronóstico y los factores determinantes de la mortalidad en pacientes gravemente enfermos en Colombia. Métodos. Estudio retrospectivo multicéntrico de cohortes realizado en el período del 2005 al 2008 en 16 instituciones de atención de salud de referencia públicas y privadas de Bogotá, Colombia, que forman parte de una red nacional de vigilancia epidemiológica y de una red hospitalaria de 4 469 camas. Se analizaron la aparición de resistencia a la meticilina y la mortalidad mediante análisis descriptivos y de tiempo transcurrido hasta un suceso; se estableció un modelo multifactorial de regresión de riesgos proporcionales de Cox para evaluar la asociación entre la resistencia a la meticilina y la mortalidad. Resultados. Se estudiaron 372 pacientes: 186 con bacteriemia por MRSA, apareados aleatoriamente con 186 con bacteriemia por Staphylococcus aureus sensible a la meticilina (MSSA). La cirugía previa, el tratamiento con antibióticos y las infecciones intrahospitalarias se asociaron independientemente con la resistencia a la meticilina. El MRSA provocó hospitalizaciones más prolongadas en los sobrevivientes (mediana de 24 frente a 18 días, P = 0,014). Los factores predictivos de mortalidad fueron: la edad del paciente, un nivel de creatinina superior a 1,21 mg/dl al ingresar en la UCI, la septicemia grave y el requerimiento de inotrópicos. El tratamiento antimicrobiano apropiado y el cambio de tratamiento antimicrobiano constituyeron factores protectores independientes, igual que el sexo masculino. Conclusiones. La resistencia a la meticilina per se no fue un factor pronóstico independiente de la mortalidad. Las condiciones previas, como la edad, la insuficiencia renal inicial, la septicemia grave y el requerimiento de inotrópicos explicaron la mortalidad observada. El tratamiento antimicrobiano apropiado seguía siendo un factor protector. Es obligatorio hacer un llamamiento para mejorar las medidas de control de las infecciones en Colombia y en otros contextos similares.

Objective. To evaluate risk factors associated with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia emergence, its prognosis, and mortality-determining factors in critically ill patients in Colombia. Methods. A multicenter, retrospective cohort study conducted in 2005–2008 at 16 public and private reference health care institutions in Bogotá, Colombia, that form part of a national epidemiological surveillance network and a hospital network with 4 469 beds. Methicillinresistant emergence and mortality were analyzed using descriptive and time-to-event analysis; a multivariate Cox proportional hazard regression model was built to test the association between methicillin resistance and mortality. Results. A total of 372 patients were studied: 186 with MRSA bacteremia, randomly matched with 186 with methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia. Previous surgery, antibiotic exposure, and hospital-acquired infections were independently associated with methicillin resistance. MRSA caused longer hospital stays among survivors (median 24 versus 18 days, P = 0.014). Mortality predictors were: patient age, creatinine level over 1.21mg/dl at ICU admission, severe sepsis, and inotropic requirement. Appropriate antimicrobial therapy and antimicrobial therapy change were independent protective factors, as was male gender. Conclusions. Methicillin resistance per se was not a mortality-independent prognostic factor. Previous conditions, such as age, baseline renal impairment, severe sepsis, and inotropy demand explained the observed mortality. Appropriate antimicrobial therapy remained a protective factor. A call to improve infection control measures in Colombia is mandatory.

Bacteriemia por Staphylococcus aureus resistente a la meticilina en la unidad de cuidados intensivos: revisión de los estudios de pronóstico / Bacteremia due to methicillin-resistant Staphylococcus aureus in intensive care unit: of prognostic studies

Staphylococcus aureus es una de los principales causas de infección de pacientes en estado crítico. La información de vigilancia muestra 32,9 % de resistencia a la meticilina y una frecuencia de aislamiento como causante de infección de 12,15 % en las unidades de cuidados intensivos, especialmente infecciones del torrente sanguíneo. No se encontraron artículos de síntesis de de los datos sobre el impacto de la resistencia de esta bacteria en la mortalidad de los pacientes gravemente comprometidos. Esta revisión de la literatura resume los estudios de pronóstico sobre la infección del torrente sanguíneo por S. aureus resistente a meticilina (SARM) en pacientes de la unidad de cuidados intensivos. Se incluyeron los artículos que evaluaron la mortalidad por bacteriemias primarias o secundarias, comparándola con controles sensibles a la meticilina o infectados por otra bacteria. No se incluyeron estudios con bacteriemias polimicrobianas. De 387 referencias, seis estudios cumplieron los criterios de inclusión. Los datos disponibles no permiten generar una conclusión sobre la mortalidad relacionada con SARM en la unidad de cuidados intensivos. Los análisis bivariados muestran un incremento de la mortalidad, el cual tiende a desaparecer cuando se controla por otras variables, como el tratamiento inicial apropiado y la gravedad del cuadro clínico. La participación de este microorganismo en la mortalidad de pacientes de la unidad de cuidados intensivos y sus determinantes, permanecen aún sin explicar.

Staphylococcus aureus is an important infectious pathogen in critically ill patients. Local surveillance shows its isolation as infectious causative pathogen at intensive care units in 12.15% of cases and a methicillin resistance rate of 32.9%, specially related with bloodstream infections. This review summarizes available prognosis studies related to methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections at intensive care unit (ICU). References with primary or secondary bacteremia patients compared with susceptible pathogen controls or different pathogen were included. Polymicrobial bacteremias were not included. 387 references were retrieved, only six studies met the inclusion criteria. The available evidence does not support a definitive conclusion about MRSA-related mortality in ICU. Increased mortality registered in bivariate analysis disappears when other covariates as appropriate initial therapy and baseline severity are adjusted. The involvement of this marker in ICU patient´s mortality and their prognosis determinants still remain unexplained.