Bacteriemias de presentación comunitaria y nosocomial por Staphylococcus aureus resistente a meticilina en hospitales españoles / Community-onset and nosocomial bacteremia due to methicillin-resistant Staphylococcus aureus in Spanish hospitals

Introducción Las infecciones de presentación comunitaria por Staphylococcus aureus resistente a meticilina (SARM) son un fenómeno creciente. Sin embargo, existe escasa información acerca de las bacteriemias de presentación comunitaria (BPC) por SARM en nuestro medio. Los objetivos de este estudio son evaluar la frecuencia, la epidemiología clínica y molecular, las características clínicas y las características pronósticas de las BPC por SARM con respecto a las bacteriemias nosocomiales (BN).Métodos Estudio de cohorte prospectivo y multicéntrico; se incluyeron todos los casos incidentes de bacteriemia por SARM en 59 hospitales españoles durante el mes de junio de 2003. Se consideró BPC a aquella que se diagnosticó en las primeras 48h de ingreso del paciente, y BN cuando se realizó posteriormente. Las cepas se tiparon mediante electroforesis en campo pulsante y multilocus sequence typing; los tipos de casete cromosómico estafilocócico mec y producción de leucocidina de Panton-Valentine se estudiaron por reacción en cadena de la polimerasa. Resultados Se incluyeron 64 bacteriemias; 21 (33%) de ellas se consideraron como BPC. En todos estos casos se encontró relación con la atención sanitaria o bien se detectó una cepa genotípicamente relacionada con las nosocomiales. No se observaron diferencias significativas entre los 2 grupos en cuanto a los datos demográficos, las características intrínsecas, el pronóstico o las características de las cepas. En relación con el foco de origen, las originadas en un catéter vascular fueron más frecuentes en las BN (el 39,5 versus el 5%; p = 0,005) y las originadas en el aparato urinario fueron más frecuentes en las BPC (el 25 versus el 0%; p = 0,001). La mayoría de las cepas perteneció a 2 clones relacionados con el clon pandémico denominado “pediátrico” (..) (AU)

Introduction Community-onset infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are increasing. However, there is little information about community-onset bacteremia (CB) due to MRSA in Spain. The objectives of this study were to evaluate the prevalence, clinical and molecular epidemiology, clinical features, and prognosis of CB due to MRSA in comparison with nosocomial bacteremia (NB).Methods Prospective multicenter cohort study; all new cases of bacteremia due to MRSA occurring during June 2003 in 59 Spanish hospitals were included. Episodes diagnosed during the first 48 hours of admission were considered CB, and otherwise, NB. Isolates were typed by pulsed field electrophoresis and multilocus sequence typing. Staphylococcal cassete chromosome mec types and Panton-Valentine leukocidin genes were studied by polymerase chain reaction. Results Sixty-four cases were included; 21 (33%) were classified as CB. In all CB cases, a relation was found with health care, or the isolate proved to be clonally related to nosocomial isolates. There were no significant differences between the groups in terms of demographic data, underlying conditions, prognosis, or characteristics of the isolates. Regarding the source of bacteremia, catheter-related cases were more frequent in NB than CB (39.5% vs 5%, P=0.005), whereas a urinary source was more frequent in CB than NB (25% vs 0%, P=0.001). Most isolates belonged to 2 clones related to the pandemic “pediatric” clone. Conclusion MRSA should be considered in empiric treatment for certain infectious syndromes in patients with healthcare-associated community-onset sepsis (AU)

Long-term control of endemic hospital-wide methicillin-resistant Staphylococcus aureus (MRSA): the impact of targeted active surveillance for MRSA in patients and healthcare workers.

OBJECTIVE: To evaluate the long-term impact of successive interventions on rates of methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection and MRSA bacteremia in an endemic hospital-wide situation. DESIGN: Quasi-experimental, interrupted time-series analysis. The impact of the interventions was analyzed by use of segmented regression. Representative MRSA isolates were typed by use of pulsed-field gel electrophoresis. SETTING: A 950-bed teaching hospital in Seville, Spain. PATIENTS: All patients admitted to the hospital during the period from 1995 through 2008. METHODS: Three successive interventions were studied: (1) contact precautions, with no active surveillance for MRSA; (2) targeted active surveillance for MRSA in patients and healthcare workers in specific wards, prioritized according to clinical epidemiology data; and (3) targeted active surveillance for MRSA in patients admitted from other medical centers. RESULTS: Neither the preintervention rate of MRSA colonization or infection (0.56 cases per 1,000 patient-days [95% confidence interval {CI}, 0.49-0.62 cases per 1,000 patient-days]) nor the slope for the rate of MRSA colonization or infection changed significantly after the first intervention. The rate decreased significantly to 0.28 cases per 1,000 patient-days (95% CI, 0.17-0.40 cases per 1,000 patient-days) after the second intervention and to 0.07 cases per 1,000 patient-days (95% CI, 0.06-0.08 cases per 1,000 patient-days) after the third intervention, and the rate remained at a similar level for 8 years. The MRSA bacteremia rate decreased by 80%, whereas the rate of bacteremia due to methicillin-susceptible S. aureus did not change. Eighty-three percent of the MRSA isolates identified were clonally related. All MRSA isolates obtained from healthcare workers were clonally related to those recovered from patients who were in their care. CONCLUSION: Our data indicate that long-term control of endemic MRSA is feasible in tertiary care centers. The use of targeted active surveillance for MRSA in patients and healthcare workers in specific wards (identified by means of analysis of clinical epidemiology data) and the use of decolonization were key to the success of the program.

[Community-onset and nosocomial bacteremia due to methicillin-resistant Staphylococcus aureus in Spanish hospitals]. / Bacteriemias de presentación comunitaria y nosocomial por Staphylococcus aureus resistente a meticilina en hospitales españoles.

INTRODUCTION: Community-onset infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are increasing. However, there is little information about community-onset bacteremia (CB) due to MRSA in Spain. The objectives of this study were to evaluate the prevalence, clinical and molecular epidemiology, clinical features, and prognosis of CB due to MRSA in comparison with nosocomial bacteremia (NB). METHODS: Prospective multicenter cohort study; all new cases of bacteremia due to MRSA occurring during June 2003 in 59 Spanish hospitals were included. Episodes diagnosed during the first 48 hours of admission were considered CB, and otherwise, NB. Isolates were typed by pulsed field electrophoresis and multilocus sequence typing. Staphylococcal cassete chromosome mec types and Panton-Valentine leukocidin genes were studied by polymerase chain reaction. RESULTS: Sixty-four cases were included; 21 (33%) were classified as CB. In all CB cases, a relation was found with health care, or the isolate proved to be clonally related to nosocomial isolates. There were no significant differences between the groups in terms of demographic data, underlying conditions, prognosis, or characteristics of the isolates. Regarding the source of bacteremia, catheter-related cases were more frequent in NB than CB (39.5% vs 5%, P=0.005), whereas a urinary source was more frequent in CB than NB (25% vs 0%, P=0.001). Most isolates belonged to 2 clones related to the pandemic "pediatric" clone. CONCLUSION: MRSA should be considered in empiric treatment for certain infectious syndromes in patients with healthcare-associated community-onset sepsis.

Impact of inappropriate empirical therapy for sepsis due to health care-associated methicillin-resistant Staphylococcus aureus.

OBJECTIVES: We investigated the influence of empirical therapy on the mortality of patients with health care-associated (HCA) sepsis caused by methicillin-resistant Staphylococcus aureus (MRSA) infections in a multicenter cohort, and the variables associated with inappropriate empirical therapy. METHODS: All new cases of infection caused by HCA-MRSA presenting with sepsis syndrome in 59 Spanish hospitals during June 2003 were prospectively followed. The main outcome variable was mortality at day 30. Predictors of mortality and of inappropriate empirical therapy were studied using multivariate logistic regression. RESULTS: We included 209 cases. Crude mortality was 23%. After controlling for severity of the underlying condition, ICU stay, presentation with severe sepsis or shock, and site of infection, inappropriate empirical therapy was associated with an increased odds of mortality (OR=3.0; 95% CI: 1.01-9.0; p=0.04). Only 21.1% of the patients received appropriate empirical therapy. Variables independently associated with appropriate therapy were recent surgery, central venous catheter and certain sites of infection (primary bacteraemia, intraabdominal infections, and respiratory tract infections). Cancer patients were at an increased risk of receiving inappropriate therapy. CONCLUSIONS: Inappropriate empirical therapy was independently associated with increased mortality in this multicenter cohort. Clinicians should be aware of the need to consider coverage against MRSA more frequently.

[Control of methicillin-resistant Staphylococcus aureus in Spanish hospitals. A survey from the MRSA 2003 GEIH/GEMARA/REIPI project]. / Medidas de control de Staphylococcus aureus resistente a meticilina en hospitales españoles. Encuesta del proyecto SARM 2003 GEIH/GEMARA/REIPI.

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main nosocomial pathogens. The incidence of MRSA infections is increasing in Spain. The objective of this study was to investigate the measures used for surveillance and control of MRSA in a sample of Spanish hospitals. METHODS: A questionnaire survey was done, including data on the incidence of MRSA infection/colonization for 2002, the microbiological methods used to study S. aureus susceptibility, and the use of control measures based on published guidelines. RESULTS: Sixty-one hospitals with a catchment population of 16 million inhabitants participated. Automatic methods were most frequently used for routine susceptibility testing. The median incidence was 0.45 cases/100 admissions; this data could be obtained from only 70% of the centers. In 59%, the incidence was indicative of high transmission. Isolation precautions were indicated for all patients with MRSA in 95% of the hospitals; screening of carriers among patients was performed in 18% to 72%, depending on the circumstances. Health care workers from at least one unit had been screened in 52% of the hospitals during 2002. Mupirocin was used for the treatment of 90% of colonized persons. CONCLUSION: There is considerable variation in the application of control measures in the hospitals surveyed. National guidelines with recommendations for MRSA control are needed in Spain.

Medidas de control de Staphylococcus aureus resistente a meticilina en hospitales españoles. Encuesta del proyecto SARM 2003 GEIH/GEMARA/REIPI / Control of methicillin-resistant Staphylococcus aureus in Spanish hospitals. A survey from the MRSA 2003 GEIH/GEMARA/REIPI project

Introducción. Staphylococcus aureus resistente a meticilina (SARM) es uno de los principales patógenos nosocomiales cuya frecuencia no deja de aumentar en España. Los objetivos de este estudio son conocer con detalle las medidas de vigilancia y control de SARM que se llevan a cabo en una amplia muestra de hospitales españoles. Métodos. Se realizó una encuesta que incluía datos de incidencia de infección/colonización por SARM durante 2002, datos sobre técnicas utilizadas para el estudio de sensibilidad de S. aureus y medidas de control basadas en las recomendaciones existentes. Resultados. Participaron 61 hospitales que atienden a una población de 16 millones de habitantes. Los métodos automatizados son los más usados para el estudio rutinario de sensibilidad. La mediana de incidencia (que sólo pudo ser referida por el 70% de hospitales) fue de 0,45 casos/100 ingresos; en el 59%, la incidencia es indicativa de elevada transmisión. En el 95% de centros se indica aislamiento de contacto para todos los pacientes con SARM; se realiza cribado de pacientes portadores entre el 18 y 72% de centros, en función de la circunstancia. En el 52% se habían estudiado todos los sanitarios de al menos una unidad en ese año. La mupirocina se utilizó como tratamiento de descolonización en el 90%. Conclusión. Existe una importante variabilidad en la aplicación de las medidas de control de SARM en los centros encuestados. Es necesario elaborar una guía consensuada de recomendaciones para el control de SARM en España (AU)

Introduction. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main nosocomial pathogens. The incidence of MRSA infections is increasing in Spain. The objective of this study was to investigate the measures used for surveillance and control of MRSA in a sample of Spanish hospitals. Methods. A questionnaire survey was done, including data on the incidence of MRSA infection/colonization for 2002, the microbiological methods used to study S. aureus susceptibility, and the use of control measures based on published guidelines. Results. Sixty-one hospitals with a catchment population of 16 million inhabitants participated. Automatic methods were most frequently used for routine susceptibility testing. The median incidence was 0.45 cases/100 admissions; this data could be obtained from only 70% of the centers. In 59%, the incidence was indicative of high transmission. Isolation precautions were indicated for all patients with MRSA in 95% of the hospitals; screening of carriers among patients was performed in 18% to 72%, depending on the circumstances. Health care workers from at least one unit had been screened in 52% of the hospitals during 2002. Mupirocin was used for the treatment of 90% of colonized persons. Conclusion. There is considerable variation in the application of control measures in the hospitals surveyed. National guidelines with recommendations for MRSA control are needed in Spain (AU)