Síndrome hemolítico urémico asociado a infección intestinal por Escherichia coli productora de shigatoxina (STEC) en pacientes chilenos: aspectos clínicos y epidemiológicos / Hemolytic uremic syndrome associated to shigatoxin producing Escherichia coli in Chilean children: clinical and epidemiological aspects

Clinical and epidemiological aspects of shigatoxin producing E. coli (STEC) infections and hemolytic uremic syndrome (HUS) are reviewed. Surveillance results from 14 sentinel centers during 2000-2002 showed a mean incidence rate of 3.4 HUS cases per 100.000 children, with the highest incidence in the 6 to 28 month age group. Disease is endemic with summer peaks. Between 1988 and 2002 we obtained the clinical characteristics of a group of 119 HUS children with the following results: mean age 16 months, bloody diarrhea 57.8 percent, no previous diarrhea 9 percent, 60 percent received antibiotics, 72 percent had oligoanuria, 53 percent required dialysis, 15 percent had seizures and 31 percent had dizziness; mortality was 3 percent. Four foodborne outbreaks have been detected in Santiago, two outbreaks occurred in household settings, one in a Day Care Center and one in a Neonatal Unit. Recommendations for diagnosis, treatment and prevention of STEC infections, including potential vaccines are discussed.

Se revisan y actualizan aspectos clínicos y epidemiológicos de las infecciones por Escherichia coli productora de shigatoxina (STEC), y el síndrome hemolítico urémico (SHU). Se incluyen resultados de una vigilancia de SHU en 14 centros centinelas (2000-2002), que mostró una incidencia promedio de 3,4 casos por 100.000 niños, 78 por ciento) en el grupo de 6 a 48 meses. Esta vigilancia reflejó una situación endémica, con aumento en verano. Se analiza la observación clínica protocolizada de 119 pacientes con SHU hospitalizados en la Región Metropolitana (RM) (1988 y 2002). Edad promedio: 16 meses. El 578 por ciento> tenía diarrea con sangre, 9 por ciento> no tenía diarrea previa, 60 por ciento> recibió antibacterianos, 72 por ciento> presentó oligoanuria y 53 por ciento> necesitó diálisis. El 31 por cientoo tuvo compromiso de conciencia y 15 por cientoo presentó convulsiones. Letalidad 3 por ciento. Se analizan brotes de STEC asociados a alimentos ocurridos en la RM en el hogar (2), un jardín infantil (1) y en un servicio de neonatología (1). Finalmente, se entregar recomendaciones para el manejo clínico y prevención, se revisan los criterios diagnósticos, nuevas estrategias terapéuticas y progresos en el desarrollo de vacunas.

Evaluación retrospectiva de la vigilancia de Streptococcus pneumoniae causante de enfermedades invasoras en adultos de la Región Metropolitana-Chile: 2000-2006 / Retrospective assessment of laboratory surveillance for invasive Streptococcus pneumoniae isolates from adults of the Metropolitan Region (Chile): 2000-2006

Este estudio evaluó el funcionamiento de la norma nacional de vigilancia de Streptococcus pneumoniae recuperado desde procesos invasores en adultos de la Región Metropolitana-Chile. Material y Métodos: Se revisaron las notificaciones correspondientes a pacientes de 15 años o más, recibidas por el ISP en el período 2000-2006, emitidas por establecimientos asistenciales de la región. Paralelamente, se revisaron los resultados de cultivos de fluidos estériles practicados en 14 hospitales estatales que atienden adultos. Resultados: Se encontró documentación de 1.429 aislados de S. pneumoniae provenientes de procesos invasores en pacientes de 15 años o más, incluyendo 1.095 notificados y 334 no notificados. La tasa de sub-notificación estimada para los 14 establecimientos visitados alcanzó a 33 por ciento. La edad y el diagnóstico fueron omitidos en 23 y 78 por ciento de las notificaciones, respectivamente. En 235 de 303 (78 por ciento) cepas aisladas de pacientes de 65 años o más, investigadas mediante reacción de Quellung, se identificaron serotipos capsulares representados en la vacuna polisácarida 23-valente. Conclusiones: El Ministerio de Salud anunció un programa de inmunización con vacuna neumocóccica 23-valente dirigido a los adultos mayores. Con miras a la futura evaluación del impacto de esta medida, los resultados de esta revisión señalan la necesidad de reforzar el cumplimento y la calidad de las notificaciones de S. pneumoniae causante de enfermedades in-vasoras.

This study assessed the performance of the national norm for laboratory surveillance of invasive Streptococcus pneumoniae in adults of the Metropolitan Region (Chile). Material and Methods. We reviewed all notifications of isolates from patients > 15 years of age received by the Institute of Public Health of Chile during the period 2000-2006, submitted by health care facilities of the study region. We also reviewed the original records of sterile fluid cultures, in 14 public adult hospitals. Results. We found documentation of 1429 invasive S. pneumoniae isolates recovered from adult patients, including 1095 reported and 334 not-reported isolates. A 33 percent under-reporting rate was estimated for the 14 hospitals where local laboratory records were inspected. Age and clinical diagnosis were omitted in 23 percent and 78 percent of the notifications, respectively. Among 303 isolates from patients > 65 years of age that were investigated with Quellung reaction, 235 (78 percent) had capsular serotypes represented in the 23-valent polysacharide vaccine. Conclusions. The Ministry of Health of Chile announced implementation of 23-valent vaccine immunization program for the elderly. In the perspective of future evaluations of the impact of this intervention, the results of this study indicate the need of reinforcing adherence and improving the quality of notifications of invasive S. pneumoniae.

Epidemiología clínica y molecular de las infecciones por Shigella spp en niños de la Región Metropolitana durante el verano 2004-2005 / Shigella spp Infections In children living In the Metropolitan RegionChile, during summer of 2004-2005

Background: Shigella spp is a frequent cause of diarrhea in children. Antimicrobials decrease the duration of diarrhea and pathogen excretion. However, the increasing resistance limits their therapeutic value. Aim: To study Shigella serotype distribution in the Metropolitan Region in Chile, and its relationship with severity of disease, antimicrobial resistance pattern and clonality. Material and methods: During summer 2004-2005, stool samples from children with diarrhea were collected in Cary Blair transpon medium and cultured. Shigella isolates were serotyped using monoclonal and polyclonal commercial antibodies. In vitro activity of ampicillin, amoxicillin/clavulanic acid, chloramphenicol, cotrimoxazol, nalidixic acid, ciprofloxacin, ceftriaxone and azythromycin was determined by minimal inhibitory concentration (MIC). Clonality was studied by pulsed-field gel electrophoresis (PFGE) using Xbal as restriction enzyme. Results: One hundred thirty nine Shigella strains were isolated (77 S sonnei and 62 S flexneri). S sonnei and S flexneri 2a serotypes were responsible for 95 percent of episodes. Children aged 2-4 years, showed a greater incidence of Shigella infections and 77 percent of episodes were treated on an ambulatory basis. High resistance levels were observed for ampicillin, cotrimoxazole, amoxicillin-clavulanic acid and chloramphenicol (67 percent, 60 percent, 56 percent and 45 percent, respectively). We found 11 resistance patterns and 61,2 percent of strains were multiresistant. There were multiple clones without a strict relationship with resistance patterns. Conclusions: Shigella infections in Metropolitan Region in Chile are associated to a restricted number of serotypes, representing a clonal expansion associated to different antimicrobial resistant patterns.

Anticuerpos séricos contra el virus hepatitis A en sujetos de nivel socioeconómico medio y bajo en comunas urbanas de Santiago / Serum antibodies against hepatitis A virus among subjects of medium and low socioeconomic levels in urban Santiago

Background: The epidemiology of hepatitis A virus (HAV) infection is closely associated to the level of hygiene and sanitation of the population. Newly industrialising areas experience a transition from high to intermediate endemicity, which is characterized by a shift in the exposure age to HAV, from early childhood to school ages or adolescence. Aim: To measure the prevalence of HAV antibodies in subjects living in urban Santiago. Subjects and methods: A HAV antibody survey in five medium and low socioeconomic level urban districts of northern Santiago, was conducted in 1996. Healthy subjects aged 1 to 39 years old were recruited from randomly selected households. Results: Five hundred three subjects were studied. Anti HAV antibodies were found in 13.2, 29.5, 59.6, 78.1, 95.6 and 98.2 percent of individuals aged 1 to 4, 5 to 9, 10 to 14, 15 to 19, 20 to 29 and 30 to 39 years old, respectively. Conclusions: The profile of positive antibodies is compatible with an intermediate pattern of transmission of HAV. The current data supports the idea that infection is shifting towards older ages. A progressive increase in the number of susceptible school age children and teenagers is propitious for the occurrence of common source hepatitis A outbreaks

Infección del tracto urinario / Urinary tract infections

Durante los últimos 10 años se han incorporado nuevos conceptos al conocimiento de la patogenia de las infecciones del tracto urinario (ITU), y se han perfeccionado métodos de estudio que permiten mejor valoración clínica de los pacientes con estas afecciones. En esta revisión se analiza la información relativa a factores de la virulencia de E. coli en tracto urinario y sobre marcadores genéticos del huésped como posibles indicadores de riesgo de recurrencia y complicaciones. También se revisaron algunas de las posibilidades que ofrecen, en el terreno clínico, los procedimientos diagnósticos recientemente propuestos para determinar el nivel anatómico de la infección