Assessing the incidence of gastroenteritis among elderly people living in long term care facilities

We conducted a systematic review and meta-analysis of the literature in order to estimate the incidence of gastroenteritis in long term care facility (LTCF) residents from published accounts of infection surveillance. PubMed, Web of Science and Google Scholar were searched using keywords 'long-term care facility', 'nursing home', 'gastroenteritis', 'surveillance', and 'incidence'. We manually searched reference lists of all articles included. The number of cases of gastroenteritis and bed-days under surveillance was recorded so as to calculate incidence and assess the influence of the study country and case definition using random effects meta-analysis and regression. We included one trial and 14 surveillance studies in the analysis, with 47% (7/15) conducted after 1995. One study focused only on gastroenteritis in residents; the remainder considered a range of infections. There were 2,071,330 combined bed-days under surveillance and 717 cases of gastroenteritis. In all, 194 cases were associated with 10 outbreaks during these studies. We observed heterogeneity between studies, which may have been due to unreported clustering of gastroenteritis cases. The mean incidence of gastroenteritis in LTCF residents was 0.40 (95% confidence interval: 0.27-0.56) episodes per 1000 bed-days. Investigators conducting studies in the USA reported incidence three times lower than investigators in other countries. Use of a case definition developed specifically for LTCFs was not associated with a higher incidence of gastroenteritis. From our analysis, residents could expect to experience gastroenteritis once every 5-10 years, which is a lower rate than that estimated from point prevalence surveys. New studies are needed to better assess the incidence and causes of gastroenteritis in LTCF residents.