Diagnóstico mediante ELISA de un brote de infección gastrointestinal por Norovirus en una guardería infantil / ELISA Diagnosis of a gastrointestinal norovirus outbreak in a nursery

La incidencia de brotes de gastroenteritis por Norovirus en niños ha sido infravalorada. Esto se ha debido principalmente a la dificultad para disponer de procedimientos diagnósticos adecuados (microscopía electrónica y reacción en cadena de polimerasa de trascripción inversa[RT-PCR]). Los nuevos métodos de enzimoinmuno ensayo (ELISA), capaces de detectar antígenos virales en heces, constituyen una alternativa diagnóstica prometedora. El objetivo de este estudio es describir la aplicación de una técnica de ELISA en la investigación de un brote de gastroenteritis por Norovirus en una guardería. En septiembre de 2003 se notificaron varios casos de gastroenteritis entre niños que acudían a una guardería. El brote afectó a 15 de los 64 niños expuestos. La sintomatología fue vómitos (100%), dolor abdominal (66%), náuseas (40%) y diarrea (40%). La duración del cuadro fue de 3 días (mediana 2 días). Tres pacientes requirieron ingreso hospitalario y todos se recuperaron con tratamiento sintomático. Se estudiaron 3 muestras de heces de 3 pacientes. La presencia de Salmonella sp, Shigella sp y Campylobacter sp se descartó por coprocultivo. La investigación de Norovirus, Rotavirus, Adenovirus y Astrovirus se realizó mediante ELISA específicos (IDEIA NLV, IDEIA Rotavirus, IDEIA Adenovirus e IDEIA Astrovirus; Dako Ltd, Ely UK). En las 3 muestras procesadas se obtuvieron resultados positivos por ELISA para Norovirus y negativos para el resto de los patógenos. La confirmación de resultados para Norovirus se llevó a cabo mediante RT-PCR. La aplicación generalizada de técnicas de ELISA permitirá ayudar a definir en nuestro entorno el papel de los Norovirus como agentes responsables de brotes de gastroenteritis aguda en niños

The incidence of gastrointestinal outbreaks caused by Norovirus in children has been underestimated. This fact is mainly due to the difficulty in the availability of adequate diagnostic procedures (electronic microscopy and Reverse Transcriptase Polymerase Chain Reaction [RTPCR]).The new Enzyme-Linked Immunosorbent Assay (ELISA) methods for the detection of viral antigens in stools represent a promising diagnostic alternative. The objective of this study was to describe the application of an ELISA technique in the investigation of an outbreak by Norovirus in a day care center. In September 2003 several cases of gastroenteritis in children attending a day care center were communicated. The outbreak affected to 15 out of 64 exposed children. The symptomatology was vomits (100%), abdominal pain (66%), nauseas(40%) and diarrhoea (40%). The duration of the symptoms was 3 days (median 2 days). Three patients required hospitalisation and all of them improved with symptomatic treatment. Three faecal samples of three patients were studied. The presence of Salmonella sp, Shigella sp and Campylobacter sp was discarded by coproculture. The investigation of Norovirus, Rotavirus, Adenovirus and Astrovirus was carried out by specific ELISAs (IDEIA NLV, IDEIA Rotavirus, IDEIA Adenovirus e IDEIA Astrovirus; Dako Ltd, Ely UK). In the three processed samples were obtained positive results for Norovirus. These results were confirmed by using RT-PCR. The results for all other pathogens were negative. The wide application of similar ELISA techniques will allow defining the role of Norovirus as agents of gastrointestinal outbreaks among children in our environment

[Air microbiology monitoring in plenum-ventilated operating rooms. Proposed standards]. / Control microbiológico aéreo de quirófanos de ventilación plena. Sugerencia de estándares.

BACKGROUND: Microbiological standard for air in plenum ventilated operating theatres are not defined. The aim of this study was to analyze the microbiological contamination of air in HUSC theatres and to establish standards of reference. METHODS: 408 air samples (80 l/sample) were taken from air intake and center of the theatres in three surgical areas, throughout five consecutive years (1991-1995). RCS air sampler was used. Media of microbiological counts were compared using the ANOVA and the Kruskall-Wallis tests. Microbiological standards were established based on upper limit of confidence interval of counts, when the degree of contamination was similar in two consecutive years. RESULTS: A falling trend of microbiological counts was observed, with statistical significance between counts found in 1992 and those found in 1994 and 1995 (p < 0.01). There was no difference between results of the three surgical areas, but there was a significant difference between counts from air intake and center of theatres, regardless the year or the surgical area (p < 0.01). During this time a significant decrease in the percentage of samples with presence of fungi (p = 0.001) was produced. The results of years 1994 and 1995 were taken for establish the microbiological standards. CONCLUSIONS: This control program allowed to evaluate and improve the hygienic conditions in the operating theatres and to establish a microbiological standards of reference for plenum ventilated theatres.