[Norovirus outbreaks in geriatric centers: importance of an early detection].

Background And Objectives: Acute gastroenteritis (AGE) outbreaks of norovirus (NV) occur frequently in nursing homes. Gastrointestinal disorders and degree of dependence of residents complicate early detection and implementation of control measures. Our study's aim was to determine the incidence of NV in elderly care centers, transmission mechanisms and circulating genotypes.

Patients And Methods: An epidemiological study of NV outbreaks reported to the Public Health Agency of Barcelona 2010-2012 was performed. The attack rate, outbreak duration, symptomatology and identified NV genotypes were analyzed.

Results: In total, 27 NV outbreaks were reported and 5 (18.5%) occurred in nursing homes (95 cases with lethality of 1.05%). The etiology of one of the five outbreaks could not be confirmed because of late notification. Four of the outbreaks were attributed to person-to-person transmission. The outbreak duration and attack rate among resident person-to-person transmission were significantly higher compared to common exposure transmission. Genotype GII.4 was predominant.

Conclusions: The identification of critical points and the use of clinical alarm systems could prevent and minimize the spreading and severity of these outbreaks.