School closure and mitigation of pandemic (H1N1) 2009, Hong Kong

Abstract

In Hong Kong, kindergartens and primary schools were closed when local transmission of pandemic (H1N1) 2009 was identified. Secondary schools closed for summer vacation shortly afterwards. By fitting a model of reporting and transmission to case data, we estimated that transmission was reduced approximately 25% when secondary schools closed.

Figure

Epidemiologic characteristics of pandemic (H1N1) 2009 in Hong Kong Special Administrative Region, People’s Republic of China, during May through August 2009. A) Time series of laboratory-confirmed pandemic (H1N1) 2009 cases classified as imported or nonimported (by age group) by date of illness onset. B) Estimates of the proportion of cases with illness onset on each day that would subsequently be identified and laboratory confirmed (reporting rates). C) Time series of nonimported pandemic (H1N1) 2009 cases by date of illness onset and the estimates of the underlying true epidemic curve (dashed line) and the fitted observed epidemic curve allowing for changes in reporting rates (solid line). Dots indicate cases reported on a given day. Number of cases plotted logarithmically. D) Distribution of ages of laboratory-confirmed pandemic (H1N1) 2009 cases over time plotted as 3-day rolling averages. Error bars indicate 95% confidence intervals.