Model Parameters and Outbreak Control for SARS

Control of the 2002–2003 severe acute respiratory syndrome (SARS) outbreak was based on rapid diagnosis coupled with effective patient isolation. We used uncertainty and sensitivity analysis of the basic reproductive number R(0) to assess the role that model parameters play in outbreak control. The transmission rate and isolation effectiveness have the largest fractional effect on R(0). We estimated the distribution of the reproductive number R(0) under perfect isolation conditions. The distribution lies in the interquartile range 0.19–1.08, with a median of 0.49. Even though the median of R(0) is <1, we found that 25% of our R(0) distribution lies at R(0) > 1, even with perfect isolation. This implies the need to simultaneously apply more than one method of control.