Acute gastroenteritis outbreaks in closed and semi-closed facilities during 2017 in Catalonia, Spain.

Acute gastroenteritis (AGE) is a leading cause of disease worldwide. The aim of this prospective observational study is to describe the epidemiology of AGE in closed and semi-closed institutions in Catalonia. In 2017, 151 outbreaks were reported; 30.5% occurred in closed and semi-closed institutions; 71.7% caused by norovirus (NoV) (1532) cases. Person-to-person transmission accounted for 75.8% of NoV outbreaks vs 46.1% in non-NoV outbreaks (p < 0.001). Attack rate for NoV outbreaks was 33.1% vs 14.3% for non-NoV outbreaks (RR = 2.3; 95%CI: 2.0-2.7). The high number of affected underscores prompt and intense preventive measures to avoid the extension and perpetuation of outbreaks in these settings.