Formulation and Estimation of the Effectiveness of Quarantine Against Emerging Diseases: Statistical Challenges

• Activity Number: 634
• Type: Invited
• Date/Time: Thursday, August 2, 2012 : 10:30 AM to 12:20 PM
• Sponsor: Section on Statistics in Epidemiology
• Author(s): Hiroshi Nishiura*+
• Companies: The University of Hong Kong
• Keywords: statistical model ; epidemic ; infectious diseases ; effectiveness ; incubation period ; outcome

Abstract

When a novel infectious disease emerges, our choice of public health countermeasures is mostly limited to non-specific public health interventions, such as quarantine, isolation and contact tracing. Unlike vaccines and antivirals, efficacy and effectiveness of non-pharmaceutical interventions have not been well studied. The explicit estimation calls for a detailed understanding of the transmission dynamics. The present study considers statistical approaches to quarantine, developing an epidemiological basis to explicitly assess the efficacy and effectiveness. The efficacy is defined as equivalent to the diagnostic accuracy of finding an infected individual following a quarantine of certain length. On the other hand, the effectiveness is defined according to public health interest, e.g., (i) the risk of allowing an infected individual into a new community, (ii) the risk of observing secondary transmissions in the community, (iii) the risk of observing a major epidemic, and (iv) the time-delay in observing a major epidemic. Only by expressing these epidemiological concepts in equations, we can determine the detailed public health performance of quarantine.