Effectiveness of control measures during the SARS epidemic in Beijing: a comparison of the Rt curve and the epidemic curve.

One of the areas most affected by SARS was Beijing with 2521 reported cases. We estimate the effective reproductive number Rt for the Beijing SARS epidemic, which represents the average number of secondary cases per primary case on each day of the epidemic and is therefore a measure of the underlying transmission dynamics. Our results provide a quantitative assessment of the effectiveness of public health control measures. More generally, our results illustrate how changes in Rt will reflect changes in the epidemic curve.