Legionelosis en un establecimiento considerado de bajo riesgo de proliferación / Legionellosis in a site with low risk of proliferation

Ante tres casos de legionelosis asociados a un establecimiento balneario se inició la investigación para confirmar la fuente de infección, determinar el riesgo y controlarlo. Entre el 26 de noviembre de 2008 y el 16 de septiembre de 2009 se realizaron seis inspecciones, con toma de temperaturas y muestras de agua para el aislamiento de Legionella pneumophila en todos los puntos de la red de agua caliente sanitaria y en las piscinas climatizadas. Se confirmó la presencia de L. pneumophila del serogrupo 1 con el mismo patrón molecular que la cepa clínica en el circuito de agua caliente sanitaria (de bajo riesgo de proliferación). La tasa de ataque bruta fue del 0,34% (intervalo de confianza del 95%: 0,09–0,94). Solo se obtuvieron muestras de agua sin presencia de L. pneumophila tras realizar cambios estructurales. Las temperaturas del agua entre 25 y 30°C, el estancamiento del agua y la exposición a primera hora de la mañana serían factores participantes en la agrupación de casos (AU)

After three cases of legionellosis associated with a spa were identified, an investigation was conducted to confirm the source of infection, determine the risk factors, and establish control measures. Between November 26, 2008 and September 16, 2009, six inspections were carried out, samples were collected for Legionella pneumophila isolation, and water temperature was determined at all the sampling points of the hot water system and at the spa pools. The presence of L. pneumophila serogroup 1 with the same molecular pattern as that found in the clinical isolate was confirmed in the hot water system (with a low proliferation risk according to legislation). The crude attack rate was 0.34% (95% CI: 0.09–0.94). Samples without L. pneumophila were obtained only after structural changes were carried out. Possible factors participating in the cluster were water temperatures between 25°C and 30°C, stagnant water and early morning exposure (AU)

[Legionellosis in a site with low risk of proliferation]. / Legionelosis en un establecimiento considerado de bajo riesgo de proliferación.

After three cases of legionellosis associated with a spa were identified, an investigation was conducted to confirm the source of infection, determine the risk factors, and establish control measures. Between November 26, 2008 and September 16, 2009, six inspections were carried out, samples were collected for Legionella pneumophila isolation, and water temperature was determined at all the sampling points of the hot water system and at the spa pools. The presence of L. pneumophila serogroup 1 with the same molecular pattern as that found in the clinical isolate was confirmed in the hot water system (with a low proliferation risk according to legislation). The crude attack rate was 0.34% (95% CI: 0.09-0.94). Samples without L. pneumophila were obtained only after structural changes were carried out. Possible factors participating in the cluster were water temperatures between 25 °C and 30 °C, stagnant water and early morning exposure.

[Norovirus outbreaks in hospitals and nursing homes in Catalonia, Spain]. / Brotes por norovirus en residencias y centros sanitarios de Cataluña.

BACKGROUND: The low infectious dose and multiple transmission routes favour the appearance of norovirus outbreaks. The objective of this study was to compare the incidence of norovirus outbreaks in hospitals and nursing homes in Catalonia. METHODS: A descriptive study of norovirus outbreaks between 15/10/2004 and 30/10/2005 was carried out. An epidemiological survey was completed for each outbreak. Norovirus in clinical samples was determined by PCR techniques. The incidence in each centre and the annual incidence of outbreaks by centre were calculated. Differences were calculated using the chi-square test and the Student's t test, taking a p value of > 0.05 as significant. RESULTS: Seventeen outbreaks (6 in hospitals and 11 in nursing homes) were detected. The global attack rate was 33.4% (652/1951) and was slightly higher in nursing homes (35.2%) than in hospitals (31.4%). A total of 94.1% (16/17) of outbreaks were caused by person-to-person transmission and only 5.9% (1/17) by foods. The mean number of days between the first and last case was 11.4 (SD = 6.9). The mean duration of symptoms was 2.39 days (SD=1.6), and was higher hospitals, 2.63 (SD=1.7), than in nursing homes, 1.97 (SD=1.7) (p < 0.0001). CONCLUSIONS: Norovirus is responsible for a large number of outbreaks due to person-to-person transmission. Control should be standardized to reduce the number and duration of outbreaks.

[Semicircular lipoatrophy: a new occupational disease]. / Lipoatrofia semicircular: un nuevo trastorno de salud relacionado con el trabajo.

In February 2007, an outbreak of 200 cases of a rare condition called semicircular lipoatrophy was notified by a company of Barcelona with about 1,000 workers. In September of that year, more that 600 cases had been notified in other workplaces, most of them in Barcelona, but also in other Spanish cities. A case-control study identified the low indoor relative humidity and working tables with thin edges as risk factors. Four months after the onset of the outbreak, the guidelines for the management of similar work-related outbreaks were published. They were addressed to health care workers of occupational health services and insurance organisations of occupational injuries and professional diseases. The implementation of the recommended interventions has been followed by a dramatic reduction of the incidence of new cases as well as by the recovery of a significant proportion of cases.

Transmission of hepatitis C virus during computed tomography scanning with contrast.

Six cases of acute hepatitis C related to computed tomography scanning with contrast were identified in 3 hospitals. A patient with chronic hepatitis C had been subjected to the same procedure immediately before each patient who developed acute infection. Viral molecular analysis showed identity between isolates from cases with acute and chronic hepatitis C.

Lipoatrofia semicircular: un nuevo trastorno de salud relacionado con el trabajo / Semicircular lipoatrophy: a new occupational disease

En febrero de 2007, una gran empresa de Barcelona notificó un brote de una rara lesión llamada lipoatrofia semicircular que afectaba a casi 200 personas de los aproximadamente 1.000 trabajadores de plantilla. En septiembre de ese mismo año se habían notificado más de 600 casos, también en otros centros de trabajo, sobre todo de Barcelona pero también del resto de España. Se realizó un estudio de casos y controles que identificó como factores de riesgo de esta lesión la baja humedad relativa del interior de los edificios y la utilización de mesas de trabajo con bordes delgados y angulares. Cuatro meses después de notificarse los primeros casos, se presentó un protocolo de actuación ante casos de lipoatrofia dirigido a los profesionales sanitarios de los servicios de prevención de las empresas y de las mutuas de accidentes de trabajo y de enfermedades profesionales. La implantación de estas medidas de control se ha traducido en una drástica reducción de la incidencia y en la curación de una proporción significativa de los casos

In February 2007, an outbreak of 200 cases of a rare condition called semicircular lipoatrophy was notified by a company of Barcelona with about 1,000 workers. In September of that year, more that 600 cases had been notified in other workplaces, most of them in Barcelona, but also in other Spanish cities. A case-control study identified the low indoor relative humidity and working tables with thin edges as risk factors. Four months after the onset of the outbreak, the guidelines for the management of similar work-related outbreaks were published. They were addressed to health care workers of occupational health services and insurance organisations of occupational injuries and professional diseases. The implementation of the recommended interventions has been followed by a dramatic reduction of the incidence of new cases as well as by the recovery of a significant proportion of cases

[Community outbreak of pneumonia due to Legionella pneumophila: importance of monitoring hospital cooling towers]. / Brote comunitario de neumonía por Legionella pneumophila: importancia del control de las torres de refrigeración en los centros sanitarios.

OBJECTIVE: Description of an outbreak of legionnaires' disease originating in one of the cooling towers of a hospital. PATIENTS AND METHODS: This study included patients with confirmed pneumonia caused by Legionella pneumophila serogroup 1 and related to the Vallcarca neighborhood of Barcelona (Spain) in August 2004. Exposure was determined by a standardized questionnaire. An environmental investigation was carried out to identify the source of the outbreak. A descriptive analysis including incidence rates estimation was performed, as well as molecular study to document the genetic identity among human and environmental strains. RESULTS: Thirty-three cases of L. pneumophila pneumonia were detected. Median age was 68 years and 70% of the affected patients were men. Incidence rate among residents in less than 200 meters of the source and older than 65 was 888.9 cases/100,000 inhabitants. Lethality rate was 6%. Four seasonal cooling towers that were not registered with the authorities were identified in a health care center. L. pneumophila was isolated from all four and at least one colony in each tower had the same genetic profile as the strains isolated from patients. CONCLUSIONS: An association was demonstrated between a community outbreak of legionellosis and unregistered seasonal cooling towers located in a hospital. All risk facilities should be registered and inspected to ensure that they fulfill current legislation requirements.

Brote comunitario de neumonía por Legionella pneumophila: importancia del control de las torres de refrigeración en los centros sanitarios / Outbreak of legionnaires’ disease linked to hospital cooling towers

Objetivo. Describir la investigación de un brote comunitario de legionelosis originado en unas torres de refrigeración de un hospital. Pacientes y métodos. Pacientes diagnosticados de neumonía por Legionella pneumophila serogrupo 1 (L. pneumophila) asociados con el barrio de Vallcarca (Barcelona) en agosto de 2004. La exposición se determinó mediante una encuesta estandarizada. Se llevó a cabo una investigación ambiental para identificar el foco emisor. Se realizó un análisis descriptivo con cálculo de tasas de incidencia, así como el estudio molecular para documentar la identidad genética entre las cepas humanas y ambientales aisladas. Resultados. Se detectaron 33 casos de neumonía por L. pneumophila. La edad media fue de 68 años y el 70% de los afectados eran varones. La tasa de incidencia en los mayores de 65 años residentes a una distancia menor o igual a 200 m del foco emisor fue de 888,9 casos/100.000 habitantes. La tasa de letalidad fue del 6%. Se identificaron cuatro torres de refrigeración estacionales no censadas ubicadas en un centro sanitario. En todas se aisló L. pneumophila y al menos una colonia de cada instalación compartía perfil genético con las cepas aisladas en los pacientes. Conclusiones. Se muestra la asociación de un brote comunitario de neumonía por Legionella y las torres de refrigeración de un centro sanitario que no estaban censadas. Se remarca la necesidad de notificar cualquier instalación de riesgo y de realizar un seguimiento para asegurar que cumplen con la legislación (AU)

Objective. Description of an outbreak of legionnaires’ disease originating in one of the cooling towers of a hospital. Patients and methods. This study included patients with confirmed pneumonia caused by Legionella pneumophila serogroup 1 and related to the Vallcarca neighborhood of Barcelona (Spain) in August 2004. Exposure was determined by a standardized questionnaire. An environmental investigation was carried out to identify the source of the outbreak. A descriptive analysis including incidence rates estimation was performed, as well as molecular study to document the genetic identity among human and environmental strains. Results. Thirty-three cases of L. pneumophila pneumonia were detected. Median age was 68 years and 70% of the affected patients were men. Incidence rate among residents in less than 200 meters of the source and older than 65 was 888.9 cases/100,000 inhabitants. Lethality rate was 6%. Four seasonal cooling towers that were not registered with the authorities were identified in a health care center. L. pneumophila was isolated from all four and at least one colony in each tower had the same genetic profile as the strains isolated from patients. Conclusions. An association was demonstrated between a community outbreak of legionellosis and unregistered seasonal cooling towers located in a hospital. All risk facilities should be registered and inspected to ensure that they fulfill current legislation requirements (AU)

Nosocomial transmission of hepatitis C virus during contrast-enhanced computed tomography scanning.

We have investigated two cases of acute hepatitis C that occurred in patients who underwent digestive endoscopy and contrast-enhanced computed tomography (CT) scanning at two different centers. Investigations to identify the sources of infection included an on-site review of diagnostic procedures, interview of the involved healthcare staff, serological testing of the patients who underwent the procedures before and after the index cases and a molecular analysis of viral isolates from the patients and from potential viremic sources. In both cases, the epidemiological investigation identified a chronic hepatitis C virus (HCV) carrier who had been subjected to CT-scanning immediately before the index patient. Genetic distance and molecular phylogenetic analyzes of HCV sequences showed a close relationship between the isolates from these carriers and those from the acute-hepatitis patients, strongly suggesting that patient-to-patient transmission had occurred during CT. This is the first report describing two well documented cases of HCV nosocomial patient-to-patient transmission during contrast-enhanced CT scanning.

[Descriptive study of hepatitis outbreaks occurring in Catalonia (1999-2003)]. / Estudio descriptivo de los brotes de hepatitis A investigados en Cataluña (1999-2003).

BACKGROUND AND OBJECTIVE: The currently low endemic level of hepatitis A in Spain favors manifestation of the disease as outbreaks among specific risk groups. The aim of this study is to analyze the hepatitis A outbreaks investigated in Catalonia (Spain) during the period of 1999 to 2003. METHODS: The criteria for including an outbreak were defined and outbreaks were classified according to the type of transmission. The variables analyzed were space, time, socio-demographic parameters, setting, risk factors, and preventive measures adopted. The incidence rate and rate ratio were calculated according to age and sex. RESULTS: Among 74 outbreaks, 73 fulfilled the inclusion criteria. Most outbreaks involved person-to-person transmission (83.8%) and the rest had a common source of infection (14.9%). In total, 334 cases were included (cumulative incidence 1999-2003: 5.27 per 100,000 inhabitants), with an average age of 24.5 years. The settings yielding the most cases were family (143), community (97) and schools/preschools (87). The number of cases per outbreak ranged from 2 to 11, except one outbreak that occurred in 83 young homosexual men with high-risk sexual practices. The main factors related to the case index or to coprimary cases included belonging to age groups with low immunity (children and young adults) and travelling to or from endemic areas. CONCLUSION: Hepatitis A outbreaks in Catalonia are still frequent. They mainly occur in the family environment, by person-to-person transmission and in the most vulnerable groups (preschool or school employees, travelers, and men who perform high-risk sexual practices with other men).

Estudio descriptivo de los brotes de hepatitis A investigados en Cataluña (1999-2003) / Descriptive study of hepatitis outbreaks occurring in Catalonia (1999-2003)

Antecedentes y objetivo. Actualmente España presenta un patrón de baja endemicidad de hepatitis A que favorece que la enfermedad se manifieste en forma de brotes en colectivos susceptibles. El objetivo de este estudio es analizar los brotes de hepatitis A investigados en Cataluña durante el período 1999-2003. Métodos. Se definieron criterios para la inclusión de los brotes y posteriormente se clasificaron según el mecanismo de transmisión. Se analizaron variables de espacio, tiempo, sociodemográficas, ámbito, factores de riesgo y medidas preventivas. Se calcularon las tasas de incidencia y la razón de tasas según edad y sexo. Resultados. De 74 brotes, 73 cumplieron los criterios de inclusión: la mayoría con transmisión persona-persona (83,8%) y el resto con fuente de infección común (14,9%). En total, se incluyeron 334 casos (incidencia acumulada 1999-2003:5,27 por 100.000 habitantes), con una mediana de edad de 24,5 años. Los ámbitos con más casos fueron el familiar (143), el comunitario (97) y el escolar/guardería (87). El número de casos por brote osciló entre 2 y 11, excepto un brote que afectó a 83 varones con prácticas homosexuales de riesgo. Pertenecer a los grupos de edad de baja inmunidad (niños y adultos jóvenes) y viajar o proceder de zonas endémicas fueron las características más importantes relacionadas con el caso índice y/o con los casos coprimarios. Conclusión. Los brotes de hepatitis A en Cataluña todavía son frecuentes. La mayoría se producen en el ámbito familiar, por transmisión persona-persona, y en los subgrupos de población más susceptibles a la infección (trabajadores de guarderías o escuelas, viajeros y varones con prácticas homosexuales de riesgo) (AU)

Background and objective. The currently low endemic level of hepatitis A in Spain favors manifestation of the disease as outbreaks among specific risk groups. The aim of this study is to analyze the hepatitis A outbreaks investigated in Catalonia (Spain) during the period of 1999 to 2003. Methods. The criteria for including an outbreak were defined and outbreaks were classified according to the type of transmission. The variables analyzed were space, time, socio-demographic parameters, setting, risk factors, and preventive measures adopted. The incidence rate and rate ratio were calculated according to age and sex. Results. Among 74 outbreaks, 73 fulfilled the inclusion criteria. Most outbreaks involved person-to-person transmission (83.8%) and the rest had a common source of infection (14.9%). In total, 334 cases were included (cumulative incidence 1999-2003: 5.27 per 100,000 inhabitants), with an average age of 24.5 years. The settings yielding the most cases were family (143), community (97) and schools/preschools (87). The number of cases per outbreak ranged from 2 to 11, except one outbreak that occurred in 83 young homosexual men with high-risk sexual practices. The main factors related to the case index or to coprimary cases included belonging to age groups with low immunity (children and young adults) and travelling to or from endemic areas. Conclusion. Hepatitis A outbreaks in Catalonia are still frequent. They mainly occur in the family environment, by person-to-person transmission and in the most vulnerable groups (preschool or school employees, travelers, and men who perform high-risk sexual practices with other men) (AU)

[Meningococcal disease in Catalonia, Spain (1990-1997)]. / Enfermedad meningocócica en Cataluña (1990-1997).

BACKGROUND AND OBJECTIVE: We aimed to study the behavior of meningococcal disease in Catalonia during the period 1990-1997, identifying the possible epidemic periods. MATERIAL AND METHOD: All cases reported to the notifiable disease system which fulfilled the criteria of confirmed or suspected cases during this period were analyzed. RESULTS: The global incidence rate was 4.8/100,000. The incidence rate for serogroup B was 1.9/100,000 and for serogroup C 0.8/100,000. The disease incidence tended to diminish slightly during the study period, with a constant annual growth of 0.11/100,000. The increased incidence of serogroup C cases in 1996-1997 was associated with an increased incidence in the 10-19 years age group. CONCLUSIONS: Globally, in the 1990-1997 period, the disease incidence tended to diminish slightly. During the last two years, an increased incidence was observed, mostly due to the increase in the number of serogroup C cases. This fact was associated with a change in the age pattern of cases, which increased in the 10-19 years age group, as observed in other countries and coinciding with epidemic periods or greater meningococcal activity.

The case-fatality rate of meningococcal disease in Catalonia, 1990-1997.

The objective was to analyse the case-fatality rate (CFR) of meningococcal disease (MD) in Catalonia, Spain. A retrospective study was carried out. Clinical histories of cases of MD reported for the period 1990-1997 in Catalonia were reviewed. For all cases, the variables gender, age, clinical type, y of presentation, province, phenotype and death by meningococcal disease were collected. The association between death and the other variables was studied by bivariate and unconditional logistic regression analysis. In the 2343 cases studied there were 146 deaths (6.2%) due to meningococcal disease. The CFR was higher in females (OR: 1.5, 95%CI: 1.1-2.1), in the 20 to 49 y (OR: 2.4, 95%CI: 1.2-4.9) and > or = 50 y (OR: 5.3, 95%CI: 2.8-10.1) age groups, in cases with septicaemia (OR: 2.4, 95%CI: 1.6-3.5), in the cases produced by serogroup A (OR: 4.7, 95%CI: 1.0-23.4) and in cases occurring during 1993 (OR: 2.1, 95%CI: 1.1-4.1) or in the province of Lleida (OR: 2.9, 95%CI: 1.2-7.2). In the multivariate analysis, death was associated with the 20-49 y age group (OR: 3.9, 95%CI: 1.8-8.4), the > or = 50 y age group (OR: 7.3, 95%CI: 3.6-14.7), septicaemia (OR: 3.1; 95%CI: 2.0-4.7) and residing in the province of Lleida (OR: 3.2; 95%CI: 1.2-8.5). The CFR of meningococcal disease in Catalonia was not associated with the emergent phenotype C:2b:P1.2,5 strain, which caused an outbreak in other regions of Spain.

Shiga toxin 2-converting bacteriophages associated with clonal variability in Escherichia coli O157:H7 strains of human origin isolated from a single outbreak.

Shiga toxin 2 (Stx2)-converting bacteriophages induced from 49 strains of Escherichia coli O157:H7 isolated during a recent outbreak of enterocolitis in Spain were examined in an attempt to identify the variability due to the stx(2)-converting phages. The bacterial isolates were divided into low-, medium-, and high-phage-production groups on the basis of the number of phages released after mitomycin C induction. Low- and medium-phage-production isolates harbored two kinds of phages but released only one of them, whereas high-phage-production isolates harbored only one of the two phages. One of the phages, phi SC370, which was detected only in the isolates with two phages, showed similarities with phage 933W. The second phage, phi LC159, differed from phi SC370 in morphology and DNA structure. When both phages were present in the same bacterial chromosome, as occurred in most of the isolates, only phi SC370 was detected in the supernatants of the induced cultures. If phi LC159 was released, its presence was masked by phi SC370. When phi SC370 was absent, large amounts of phi LC159 were released, suggesting that there was some regulation of phage expression between the two phages. To our knowledge, this is the first description of clonal variability due to phage loss. The higher level of phage production was reflected in the larger amounts of Stx2 toxin produced by the cultures. Some relationship between phage production and the severity of symptoms was observed, and consequently these observations suggest that the virulence of the isolates studied could be related to the variability of the induced stx(2)-converting phages.

[Imported tuberculosis: an emerging disease in industrialised countries]. / Tuberculosis importada: una enfermedad emergente en países industrializados.

BACKGROUND: The aim of this study was to describe the characteristics of imported tuberculosis (TB) in Barcelona during 1999 and 2000. MATERIAL AND METHOD: Epidemiological surveillance questionnaire. RESULTS: During 1999 and 2000, a 7.9% decrease in TB cases was observed among the native population in Barcelona, whereas cases among immigrants grew up to 47.2%. In 2000, 449 TB cases were detected among the native population (incidence, 29.5/100,000) and 121 among immigrants (incidence, 555.9/100,000). Three outbreaks were identified, involving one Indian community (11 cases), two Dominican families (4 cases) and one city school (2 cases) whose index case was a cooperant. Isolated strains of Mycobacterium tuberculosis at the first, second and third outbreak were multisensitive, multidrug-resistant and isoniazid-resistant, respectively. CONCLUSIONS: The emergence of imported TB cases in Barcelona over 1999 and 2000 suggests that current preventive guidelines must be reviewed.

Tuberculosis importada: una enfermedad emergente en países industrializados / Imported tuberculosis: an emerging disease in industrialised countries

FUNDAMENTO: Describir las características de la tuberculosis importada en Barcelona durante 1999 y 2000. MATERIAL Y MÉTODO: Encuesta epidemiológica. RESULTADOS: En el año 2000 se detectaron 449 casos de tuberculosis en población autóctona (incidencia 29,5/100.000) y 121 en inmigrantes (incidencia 555,9/100.000).Entre 1999 y 2000 la tuberculosis ha disminuido un 7,9 por ciento en la población autóctona de Barcelona, mientras que ha aumentado un 47,2 por ciento en inmigrantes. Hubo tres brotes epidémicos: una comunidad hindú (11 casos), dos familias dominicanas (4 casos) y una escuela (dos casos) cuyo caso índice fue una cooperante. Las cepas de Mycobacterium tuberculosis del primer brote fueron sensibles a todos los fármacos, las del segundo resistentes a los de primera línea y las del tercero resistentes a isoniacida. CONCLUSIONES: La evolución de la tuberculosis en Barcelona en el último bienio confirma la emergencia de casos importados que demandan una revisión de las medidas de control. (AU)