ABSTRACT
Several viruses have been associated with acute gastroenteritis (AGE), and group A rotavirus (RVA) and nor-ovirus (NoV) are the most prevalent. This study aimed to assess their prevalence among children hospitalised for diarrhoea during a three-year surveillance study. From May 2008-April 2011, overall positivity rates of 21.6% (628/2904) and 35.4% (171/483) were observed for RVA and NoV, respectively. The seasonality observed indicated distinct patterns when both viruses were compared. This finding may explain why hospitalisation for AGE remains constant throughout the year. Continuous AGE monitoring is needed to better assess the patterns of infection.
Subject(s)
Humans , Rotavirus Infections/transmission , Caliciviridae Infections/transmission , SeasonsABSTRACT
Outbreaks of acute gastroenteritis are a public health problem. Norovirus is known as the most common cause (50%). In Chile, immediate notification allows surveillance of these events. We describe an acute gastroenteritis outbreak that occurred in Antofagasta region, between March and April 2010. An observational study was conducted to perform the outbreak investigation. Local residents who met case definition were included. Stool samples, epidemiological surveys and environmental samples were requested. The outbreak began approximately on March 8, 2010 and lasted until April 28 with 31,036 reported cases (rate 54 per 1000 inhabitants). The most affected age group was between 25 and 44 years, and diarrhea was the main symptom (97% of cases). We determined the presence of norovirus genogroup II in clinical and environmental samples. This outbreak was caused by consumption of raw vegetables from La Chimba, which were watered and contaminated with treated sewage containing low concentration of free residual chlorine. Subsequently, the outbreak spread from person to person in a poor sanitary environment.
Antecedentes: Los brotes por gastroenteritis aguda constituyen un problema de salud pública. Se conoce al norovirus como la causa más común (50%). En Chile, la vigilancia de estos eventos, se establece mediante la notificación inmediata. Objetivo: Investigar y caracterizar el brote de gastroenteritis aguda ocurrido en la Región de Antofagasta, durante los meses de marzo y abril de 2010. Método: Se efectuó un estudio observacional descriptivo para realizar la investigación de brote. Se incluyó a residentes de la región que cumplían con la definición de caso. Se solicitó muestras de deposición, encuesta epidemiológica y muestras ambientales. Resultados: Se estimó que el brote comenzó el 8 de marzo de 2010 y duró hasta el 28 de abril del mismo año; se notificaron 31. 036 casos (tasa 54 por 1.000 habitantes). El grupo de 25 y 44 años de edad fue el más afectado y la diarrea fue el síntoma predominante (97% de los casos). Se determinó la presencia de norovirus genogrupo II en muestras clínicas y ambientales. Conclusiones: El brote se originó por el consumo crudo de hortalizas que provenían del sector La Chimba, las que fueron regadas y contaminadas con agua servida tratada que contenía baja concentración de cloro libre residual y posteriormente se propagó por transmisión persona-persona, en un ambiente sanitario deficiente.
Subject(s)
Adolescent , Adult , Child, Preschool , Female , Humans , Infant , Male , Middle Aged , Caliciviridae Infections/epidemiology , Disease Outbreaks , Gastroenteritis/epidemiology , Norovirus/isolation & purification , Acute Disease , Caliciviridae Infections/transmission , Chile/epidemiology , Feces/virology , Gastroenteritis/virologyABSTRACT
Os norovírus (NoV) foram os primeiros agentes virais ligados à doença gastrointestinal, entretanto, eles foram, por muito tempo, considerados como causa secundária de gastroenterite, após os rotavírus. O desenvolvimento de técnicas moleculares voltadas ao diagnóstico dos NoV forneceu dados mais claros sobre o impacto epidemiológico desses vírus, os quais são, atualmente, reconhecidos não apenas como principal causa de surtos de gastroenterite não bacteriana, mas também como causa importante de gastroenterite esporádica em crianças e adultos. Esta revisão enfoca os conhecimentos necessários para compreender a sua morfologia, genética, transmissão, patogênese e controle. Uma vez que não há vacina disponível, a prevenção da infecção por NoV depende principalmente de medidas de higiene da comunidade e pessoais.
Although noroviruses (NoVs) were the first viral agents linked to gastrointestinal disease, for a long time they have been considered secondary cause of gastroenteritis, second to rotaviruses as etiologic agents. The development of molecular techniques in diagnosing NoV provided a clearer insight into the epidemiological impact of these viruses, which are currently recognized not only as the leading cause of non-bacterial gastroenteritis outbreaks, but also as a major cause of sporadic gastroenteritis in both children and adults. This review focuses on the required knowledge to understand their morphology, genetics, transmission, pathogenesis, and control. Since no vaccine is available, prevention of NoV infection relies mainly on strict community and personal hygiene measures.