Aim: We report a quantification and visualisation of the association between the time to notify public health service (PHS) and the duration and size of institutional gastroenteritis outbreaks, and explore the seasonality and trend of the outbreaks.
Method: Descriptive analysis was performed on institutional gastroenteritis outbreak data from a North Island PHS (1 January 2009-31 December 2014). Time-series analysis was used to explore the seasonality and trend of outbreaks. Multivariate analyses were performed to quantify the association between the time to notify PHS and the duration and size of outbreaks.
Results: One hundred and seventy-five gastroenteritis outbreaks (from 58 facilities) were included in descriptive analyses. A significant increasing trend (p=0.01) without seasonal pattern was confirmed by time-series analysis. Shorter notification time was associated with shorter duration and smaller size of outbreaks, eg, duration of outbreaks when time to notify was ≥7 days, was 3.4 days (p=0.001, 95% CI=3.1-3.7) longer than baseline time to notify (0-1 day).
Conclusion: Prompt notification to the PHS appears to be a factor associated with reduced outbreak duration and size.