Persistence of viable but nonculturable Legionella pneumophila state in hospital water systems: A hidden enemy?

There is little evidence of the long-term consequences of maintaining sanitary hot water at high temperatures on the persistence of Legionella in the plumbing system. The aims of this study were to describe the persistence and genotypic variability of L. pneumophila in a hospital building with two entirely independent hot water distribution systems, and to estimate the thermotolerance of the genotypic variants by studying the quantity of VBNC L. pneumophila. Eighty isolates from 55 water samples obtained between the years 2012-2017 were analyzed. All isolates correspond to L. pneumophila serogroup 6. The isolates were discriminated in four restriction patterns by pulsed-field gel electrophoresis. In one installation, pattern A + Aa predominated, accounting for 75.8 % of samples, while the other installation exhibited pattern B as the most frequent (81.8 % of samples; p < 0.001). The mean temperature of the isolates was: 52.6 °C (pattern A + Aa) and 55.0 °C (pattern B), being significantly different. Nine strains were selected as representative among patterns to study their thermotolerance by flow-cytometry after 24 h of thermic treatment. VBNC bacteria were detected in all samples. After thermic treatment at 50 °C, 52.0 % of bacteria had an intact membrane, and after 55 °C this percentage decreased to 23.1 %. Each pattern exhibited varying levels of thermotolerance. These findings indicate that the same hospital building can be colonized with different predominant types of Legionella if it has independent hot water installations. Maintaining a minimum temperature of 50 °C at distal points of the system would allow the survival of replicative L. pneumophila. However, the presence of Legionella in hospital water networks is underestimated if culture is considered as the standard method for Legionella detection, because VBNC do not grow on culture plates. This phenomenon can carry implications for the Legionella risk management plans in hospitals that adjust their control measures based on the microbiological surveillance of water.

Role of hot water temperature and water system use on Legionella control in a tertiary hospital: An 8-year longitudinal study.

Although measures to minimize Legionella colonization in sanitary hot water installations are well established, there is little evidence of their long-term effectiveness in hospital buildings. During an 8-year period, hot water in a large hospital building was sampled monthly in areas with suitable dimensioning and recirculation and in areas with dead legs and low-use taps. In the former areas, the percentage of Legionella-negative samples was 83.2% when the temperature was ≥55%, 64.9% when between 50.1 °C and 54.0 °C, and 51.6% when ≤50 °C (p for trend <0.001). In the highest temperature group, no samples with ≥103 cfu/L were observed. In poorly designed areas, only 44.7% of samples were negative, and 28.9% presented ≥103 cfu/L although reaching 55 °C. In these areas, multivariate analysis showed that if hot water supplies were not used daily, the risk of Legionella colonization was greater than two-fold (odds ratio: 2.84; 95% confidence interval: 1.26-6.41), and the risk of finding Legionella concentrations ≥103 cfu/L was more than three-fold (odds ratio: 3.18; 95% confidence interval: 1.36-7.46), regardless the temperature. These findings indicate that the effectiveness of maintaining sanitary hot water at a minimum temperature of 55 °C is significantly better than that at 50 °C for the environmental control of Legionella but only in installations with suitable dimensioning and recirculation. In installations that do not meet these conditions, high temperatures alone result in insufficient control.

Control of endemic extensively drug-resistant Acinetobacter baumannii with a cohorting policy and cleaning procedures based on the 1 room, 1 wipe approach.

BACKGROUND: Our institution experienced an endemic situation with extensively drug-resistant (XDR) Acinetobacter baumannii in the intensive care units (ICUs). Here, we describe the long-term results of the implementation of a screening and cohorting policy and new cleaning techniques based on a procedure that we call the 1 room, 1 wipe approach. METHODS: We conducted a 4-year quasi-experimental study in the ICUs of an 800-bed teaching hospital. The main actions implemented were active surveillance of XDR A baumannii and cohorting of carriers and introducing new cleaning techniques intended to avoid sharing wipes between rooms. RESULTS: XDR A baumannii significantly decreased from 132 cases in 2011 to 8 cases in 2014 and from 10.78 cases per 1,000 patient days in 2011 to 0.69 cases per 1,000 patient days in 2014. Segmented regression analysis showed that after implementing the measures, the monthly rates presented a sustained negative slope, with a significant change of -0.623 (P = .002). CONCLUSIONS: The prompt identification and isolation of patients and adequate environmental cleaning are effective measures for reducing XDR A baumannii in ICUs. The 1 wipe, 1 room approach should be considered a standard measure for cleaning hospital facilities to avoid cross-transmission as a result of reusable cleaning wipes.

Microbiological monitoring of flexible bronchoscopes after high-level disinfection and flushing channels with alcohol: Results and costs.

BACKGROUND: Routine microbiological surveillance of flexible bronchoscopes is recommended in different guidelines. The study aims to assess whether bronchoscopes reprocessing methods achieved an appropriate decontamination level and whether manual flushing of 70% ethyl alcohol at the end of the cycle reduces the risk of microbiological contamination. METHODS: 18 different bronchoscopes were cultured on a monthly basis during a four-year period to examine growing of bacteria, fungi and mycobacteria. 9 equipment were usually disinfected using automatic reprocessors, and the other 9 equipments were manually disinfected. Additional manual flushing of bronchoscope's channels with 70% ethyl alcohol at the end of each disinfection cycle, was implemented for automatically reprocessed equipments for a two-year period. RESULTS: A total of 620 samples were obtained. 564 samples (91.0%) tested negative and 56 samples (9%) tested positive for at least one specimen, of whom 3% were pathogenic or potentially pathogenic microorganisms. Only one positive sample was detected among the 167 alcohol treated bronchoscopes (0.6%), whereas before the introduction of this technique the percentage of contamination with risk pathogens was 4.1% (p = 0.04). The mean annual cost of the surveillance program was estimated at 23,035 euros, and the mean cost for bronchoscope was 111.5 euros. CONCLUSIONS: The results of our study support to improve the final reprocessing of bronchoscope channels by means of additional manual flushing with 70% ethyl alcohol after each disinfection cycle. Routine microbiologic monitoring of endoscopes is both time-consuming and expensive but could be saved by implementing a highly efficient decontaminating procedure.

Environmental contamination by multidrug-resistant microorganisms after daily cleaning.

We analyzed 91 samples of high-touch surfaces obtained within the first hour after daily cleaning in intensive care unit rooms occupied with patients with multidrug-resistant organisms (MDROs). We determined that 22% of high-touch surfaces in rooms with methicillin-resistant Staphylococcus aureus patients and 5% of high-touch surfaces in rooms with multiresistant Pseudomonas aeruginosa patients were colonized with the same strain as the patient. We postulated that textile cleaning wipes could be contaminated with MDROs and may contribute to its spreading within the room.

Gestión del riesgo asociado a los alérgenos en los comedores escolares de la ciudad de Barcelona / Management of the risks associated with allergens in school canteens in Barcelona (Spain)

Objetivo. Determinar la demanda y el tipo de dietas especiales para alumnos con alergias o intolerancias alimentarias (AIA) en los comedores escolares de Barcelona durante el curso 2011-12, y conocer la implementación de autocontroles y medidas preventivas para la gestión de alérgenos, así como la relación entre la aplicación de estas medidas con diversas variables. Métodos. Estudio descriptivo de una muestra representativa de escuelas (n = 129). Las variables dependientes recogieron información sobre los datos poblacionales de los centros y el alumnado, la demanda de menús especiales y la implementación de medidas preventivas. Las variables independientes fueron la gestión del comedor, el número de comensales y los autocontroles para la gestión de alérgenos. Para las escuelas que elaboraban comidas (n = 92) se calculó un índice a partir de las preguntas de medidas preventivas. Mediante prueba t de Student se compararon las medias de los índices, estratificando según las variables independientes. Resultados. El 89% de las escuelas sirvieron dietas AIA (1507 dietas AIA/día, el 5% del total de los menús) y el 65% no disponían de un plan de control de alérgenos. La media de los índices fue de 11,6 sobre 17. Los comedores gestionados externamente, con más comensales y que disponían de autocontroles, implementaron más medidas preventivas de gestión de alérgenos (p < 0,05). Conclusiones. Un alto porcentaje de centros manifiestan llevar a cabo medidas preventivas en el proceso de elaboración y servicio de menús especiales. Desde los servicios de inspección sanitaria es necesario promover la implementación de un plan de control de alérgenos en los comedores escolares para gestionar este riesgo alimentario (AU)

Objective. To determine demand for special meals and their types for students with food allergies or intolerances (FAI) in school canteens in Barcelona (Spain) during the 2011-12 school year, and to ascertain the degree of implementation of self-assessment plans and preventive measures for the management of allergens, and the relationships between the application of such measures and other variables. Methods. A descriptive study was performed of a representative sample of schools (n = 129). The dependent variables collected data on the schools and students, the level of demand for special meals, and the implementation of preventive measures. Independent variables consisted of canteen management, the number of users, and whether self-assessment plans were implemented. For those schools that prepared meals (n = 92), an index was calculated from the questions on preventive measures. Student t-tests were used to compare the means of the indices with stratification by the independent variables. Results. A total of 89% of schools served special meals for students with FAI (1,507 special meals per day, 5% of all meals) and 65% had no allergen control plan. The mean of the indices was 11.6 out of 17. Externally managed canteens, with more users and with self-assessment plans, implemented more preventive measures for allergen management (p < 0.05). Conclusions. A high proportion of schools report carrying out preventive measures in the process of preparing and serving special meals. Those with self-assessment plans have better preventive practices. To manage this food-related risk, food hygiene inspection services should promote the implementation of allergen control plans in school canteens (AU)

[Management of the risks associated with allergens in school canteens in Barcelona (Spain)]. / Gestión del riesgo asociado a los alérgenos en los comedores escolares de la ciudad de Barcelona.

OBJECTIVE: To determine demand for special meals and their types for students with food allergies or intolerances (FAI) in school canteens in Barcelona (Spain) during the 2011-12 school year, and to ascertain the degree of implementation of self-assessment plans and preventive measures for the management of allergens, and the relationships between the application of such measures and other variables. METHODS: A descriptive study was performed of a representative sample of schools (n=129). The dependent variables collected data on the schools and students, the level of demand for special meals, and the implementation of preventive measures. Independent variables consisted of canteen management, the number of users, and whether self-assessment plans were implemented. For those schools that prepared meals (n=92), an index was calculated from the questions on preventive measures. Student t-tests were used to compare the means of the indices with stratification by the independent variables. RESULTS: A total of 89% of schools served special meals for students with FAI (1,507 special meals per day, 5% of all meals) and 65% had no allergen control plan. The mean of the indices was 11.6 out of 17. Externally managed canteens, with more users and with self-assessment plans, implemented more preventive measures for allergen management (p<0.05). CONCLUSIONS: A high proportion of schools report carrying out preventive measures in the process of preparing and serving special meals. Those with self-assessment plans have better preventive practices. To manage this food-related risk, food hygiene inspection services should promote the implementation of allergen control plans in school canteens.

A large sustained endemic outbreak of multiresistant Pseudomonas aeruginosa: a new epidemiological scenario for nosocomial acquisition.

BACKGROUND: Studies of recent hospital outbreaks caused by multiresistant P.aeruginosa (MRPA) have often failed to identify a specific environmental reservoir. We describe an outbreak due to a single clone of multiresistant (MR) Pseudomonas aeruginosa (PA) and evaluate the effectiveness of the surveillance procedures and control measures applied. METHODS: Patients with MRPA isolates were prospectively identified (January 2006-May 2008). A combined surveillance procedure (environmental survey, and active surveillance program in intensive care units [ICUs]) and an infection control strategy (closure of ICU and urology wards for decontamination, strict compliance with cross-transmission prevention protocols, and a program restricting the use of carbapenems in the ICUs) was designed and implemented. RESULTS: Three hundred and ninety patients were identified. ICU patients were the most numerous group (22%) followed by urology patients (18%). Environmental surveillance found that 3/19 (16%) non-ICU environmental samples and 4/63 (6%) ICU samples were positive for the MRPA clonal strain. In addition, active surveillance found that 19% of patients were fecal carriers of MRPA. Significant changes in the trends of incidence rates were noted after intervention 1 (reinforcement of cleaning procedures): -1.16 cases/1,000 patient-days (95%CI -1.86 to -0.46; p = 0.003) and intervention 2 (extensive decontamination): -1.36 cases/1,000 patient-days (95%CI -1.88 to -0.84; p < 0.001) in urology wards. In addition, restricted use of carbapenems was initiated in ICUs (January 2007), and their administration decreased from 190-170 DDD/1,000 patient-days (October-December 2006) to 40-60 DDD/1,000 patient-days (January-April 2007), with a reduction from 3.1 cases/1,000 patient-days in December 2006 to 2.0 cases/1,000 patient-days in May 2007. The level of initial carbapenem use rose again during 2008, and the incidence of MRPA increased progressively once more. CONCLUSIONS: In the setting of sustained MRPA outbreaks, epidemiological findings suggest that patients may be a reservoir for further environmental contamination and cross-transmission. Although our control program was not successful in ending the outbreak, we think that our experience provides useful guidance for future approaches to this problem.

Influence of carbapenem resistance on mortality and the dynamics of mortality in Pseudomonas aeruginosa bloodstream infection.

OBJECTIVE: We aimed to study the influence of carbapenem resistance on attributable mortality in a cohort of patients with Pseudomonas aeruginosa bacteremia. METHODS: Data on 121 episodes of P. aeruginosa bacteremia occurring between January and December 2005 were retrospectively analyzed. RESULTS: Thirty-three episodes were caused by carbapenem-resistant P. aeruginosa (CRPA) strains and 88 by carbapenem-susceptible P. aeruginosa (CSPA) strains. There was no significant difference in mortality between the groups (33% in CRPA vs. 30% in CSPA; p = 0.69). However, a Kaplan-Meier survival analysis showed that in the first 48h after the onset of bacteremia, there was a lower cumulative mortality proportion in the CRPA group than in the CSPA group (13% vs. 50%; p = 0.026). The independent risk factors associated with death in P. aeruginosa bacteremia were clinical presentation with severe sepsis (odds ratio (OR) 38, 95% confidence interval (CI) 10.2-142.2) and bacteremia of high-risk origin (OR 6.6, 95% CI 1.6-26.9). CONCLUSIONS: According to our data, carbapenem resistance was not associated with higher mortality in patients with P. aeruginosa bacteremia. The slower initial mortality in the CRPA group might have implications in the design of the optimal antibiotic policy strategy.

Clinical impact of imipenem-resistant Pseudomonas aeruginosa bloodstream infections.

OBJECTIVES: To describe the incidence and clinical characteristics of imipenem-resistant (IR) Pseudomonas aeruginosa bacteraemia. METHODS: We performed a retrospective study including all episodes of IR P. aeruginosa bacteraemia seen from January 2003 to December 2005 in a tertiary teaching hospital. RESULTS: There were 108 episodes of IR P. aeruginosa bacteraemia, which represented an incidence of 0.14 episodes per 1000 patient-days in 2003 and 0.11 episodes per 1000 patient-days in 2005. 83 of the episodes (77%) were nosocomially acquired. Most of patients had at least one underlying disease and had previously received antimicrobial treatment. The most frequent source was the urinary tract (31%), followed by unknown origin (22%). A total of 23 (21%) episodes were polymicrobial and 51 (47%) were caused by multidrug-resistant strains. The independent risk factors for mortality from IR P. aeruginosa bloodstream infection were a high-risk source of the bacteraemia (OR: 4.6; 95% CI 1.7-12.4; p=0.01), and presentation with severe sepsis (OR: 2.8; 95% CI 1-7.8; p=0.05). CONCLUSIONS: Our study shows that the rates of IR P. aeruginosa bacteraemia remained stable throughout the study period. The source of bacteraemia and the clinical presentation with severe sepsis were the main determinants of the prognosis.

Timing of hepatitis B vaccination: its effect on vaccine response in health care workers.

We assessed the effect of timing and other biological variables on immune response among health care workers (HCW) vaccinated with hepatitis B vaccine. A total of 2.058 HCW received three doses and were tested for anti-HBs within 6 months. 92.2% of the HCW had evidence of seroprotection. Multivariable analysis showed that controlling for age, the estimated non-response OR associated with a delayed second dose was 2.16 (95% CI: 1.46, 3.18, p=0.004). We found a decreasing response rate with increasing age. Particular attention should be given to those HCW who are late for the second vaccine dose and to older subjects.

Comparative cost of selective screening to prevent transmission of methicillin-resistant Staphylococcus aureus (MRSA), compared with the attributable costs of MRSA infection.

The annual cost of a screening program to detect methicillin-resistant Staphylococcus aureus (MRSA) in a teaching hospital in Spain was 10,261 Euro. The average cost per MRSA infection was 2,730 Euro; therefore, the cost of the program would be covered if it only prevented 4 infections per year (11% of the total number of MRSA infections at our hospital).

[Gender and ischemic heart disease]. / Género y cardiopatía isquémica.

Physiological and pathological processes differ in men and women, depending on factors such as sex and sociological and anthropological characteristics. However, many diseases are still approached from a masculine point of view. In this respect, ischemic heart disease is one of the diseases that most clearly reflects biological differences and social inequalities. In women, the disease presents at a more advanced age, and presentation is frequently atypical with a higher prevalence of comorbidities and greater severity. Consequently, treatment and outcome differ from those in men. Additionally, women differ in their knowledge, and beliefs regarding ischemic heart disease, as well as in their attitudes at symptom onset. Therefore, clinical practice should place significant emphasis on all these aspects in order to avoid inequalities between men and women in the correct diagnosis, treatment, prevention, and rehabilitation of ischemic heart disease.

Género y cardiopatía isquémica / Gender and ischemic heart disease

Tanto el sexo como los aspectos sociológicos y antropológicos relacionados con el género son factores que contribuyen a particularizar los procesos fisiológicos y patológicos de mujeres y hombres. Sin embargo, el abordaje integral de muchas enfermedades se realiza desde la perspectiva masculina. En este sentido, la cardiopatía isquémica (CI) es una de las enfermedades donde se pueden ejemplificar claramente las diferencias biológicas y las desigualdades sociales. Las mujeres presentan la enfermedad en edades más avanzadas que los hombres, la forma de aparición es más frecuentemente «atípica» y está asociada con una mayor comorbilidad y gravedad. Por tanto, el tratamiento y el pronóstico es diferente. Además, también se han observado diferencias en relación con el conocimiento y las creencias sobre la enfermedad, así como en las actitudes adoptadas cuando aparecen los primeros síntomas. Es preciso tener en cuenta todos estos aspectos biológicos y de género porque frecuentemente ocasionan desigualdades entre los hombres y las mujeres, tanto en relación con el diagnóstico certero de la CI como en el tratamiento, la prevención o la rehabilitación posterior (AU)

Physiological and pathological processes differ in men and women, depending on factors such as sex and sociological and anthropological characteristics. However, many diseases are still approached from a masculine point of view. In this respect, ischemic heart disease is one of the diseases that most clearly reflects biological differences and social inequalities. In women, the disease presents at a more advanced age, and presentation is frequently atypical with a higher prevalence of comorbidities and greater severity. Consequently, treatment and outcome differ from those in men. Additionally, women differ in their knowledge, and beliefs regarding ischemic heart disease, as well as in their attitudes at symptom onset. Therefore, clinical practice should place significant emphasis on all these aspects in order to avoid inequalities between men and women in the correct diagnosis, treatment, prevention, and rehabilitation of ischemic heart disease (AU)

Infecciones nosocomiales. Evaluación de los objetivos del Plan de Salud de Cataluña para el año 2000 / Nosocomial infections. Evaluation of the objectives of the Health Plan for Catalonia for the year 2000

Fundamento y objetivos: Las infecciones nosocomiales (IN) fueron uno de los problemas prioritarios de salud incluidos en el Plan de Salud de Cataluña en 1991, y para el que se fijaron cinco objetivos a conseguir en el conjunto de hospitales de Cataluña hasta el año 2000, considerando el año 1990 como base de referencia. Cuatro de los objetivos eran de disminución de la prevalencia: la prevalencia global de IN y de infectados, por lo menos en un 15%; la de infectados en el área de atención intensiva, por lo menos en un 10%; en el área de cirugía, por lo menos en un 20%, y el quinto objetivo, situar la prevalencia en cirugía limpia por debajo del 3%. El objetivo del presente trabajo es evaluar hasta qué punto se han alcanzado estos objetivos. Población y método: La evaluación se ha realizado mediante el análisis de los datos proporcionados por el estudio de prevalencia de las IN (EPINCAT) desarrollado anualmente con carácter voluntario por un grupo de hospitales. Resultados: La prevalencia de IN disminuyó desde el 10,4% en 1990 hasta el 8,1% en el año 2000, y la de pacientes con IN desde un 9,2 hasta un 7,0%, y los dos primeros objetivos se alcanzaron ya en los primeros años de ejecución del plan. En atención intensiva la prevalencia cruda de IN no ha disminuido, aunque al estandarizar según las características de los pacientes estudiados en 1990 la prevalencia es inferior a la prevista. En cuidados intensivos se ha observado un aumento de la gravedad de los pacientes ingresados y de la proporción que recibe procedimientos asistenciales. La prevalencia en el área de cirugía descendió del 7,0 al 4,3%, y el objetivo propuesto se alcanzó en los primeros años del plan. El objetivo de reducción en cirugía limpia se alcanzó ya en 1992. Conclusiones: Según el plan de salud, en el período 1990-2000 la prevalencia de IN ha disminuido en los hospitales de Cataluña. El plan ha demostrado ser una buena herramienta para dinamizar y orientar las actividades dedicadas a la prevención y control de las infecciones nosocomiales en Cataluña (AU)

Background and objectives: Nosocomial infections (NI) were one of the priority health problems included in the Framework Document for the Development of the Health Plan for Catalonia for the year 2000 which was written in 1991. Considering 1990 as reference date, five objectives to achieve in 2000 by Catalonian hospitals were fixed. Four of them were prevalence-reduction aims: 15% reduction of overall prevalence, 15% reduction of infected patients prevalence, 10% reduction of infected patients at intensive care units prevalence, and 20% reduction of infected ones at surgical areas prevalence. The last objective was to diminish clean surgery infection prevalence under 3%. The main purpose of this paper will be to evaluate whether this objectives have been completely accomplished. Subjects and method: Data from the Study of Nosocomial Infections Prevalence were analized. Results: NI overall prevalence decrease from 10.4% in 1990 to 8.1% in 2000. Infected patient prevalence also diminished from 9.2% to 7.0%. Both objectives were achieved in the early stages of the study period. The intensive care units infection crude prevalence have not decreased. However the prevalence is lower than expected when it is standardized for specific 1990 patients variables. Surgical area infection prevalence sunk from 7.0% to 4.3%. The clean surgery objective was achieved in 1992. Conclusions: NI prevalence has decreased in Catalonian hospitals between 1990 and 2000 according to Catalonian Health Plan. The plan constitutes a good tool in order to dinamize and orient prevent activities related to control NI in Catalonia (AU)