On the quarantine period for ebola virus.

Charles N Haas

doi:10.1371/currents.outbreaks.2ab4b76ba7263ff0f084766e43abbd89

Abstract

Background: 21 days has been regarded as the appropriate quarantine period for holding individuals potentially exposed to Ebola Virus (EV) to reduce risk of contagion. There does not appear to be a systematic discussion of the basis for this period. Methods: The prior estimates for incubation time to EV were examined, along with data on the first 9 months of the current outbreak. These provided estimates of the distribution of incubation times. Results: A 21 day period for quarantine may result in the release of individuals with a 0.2 - 12% risk of release prior to full opportunity for the incubation to proceed. It is suggested that a detailed cost-benefit assessment, including considering full transmission risks, needs to occur in order to determine the appropriate quarantine period for potentially exposed individuals.

Highlights

To reduce the spread, it is necessary and desirable to quarantine each individual who might have been exposed for a sufficient time for either infection to occur or until it can be assured that there is not likely to be infection
According to the Centers for Disease Control and Prevention1: “When someone has been exposed to a contagious disease and it is not yet known if they have caught it, they may be quarantined or separated from others who have not been exposed to the disease
Nishiura[6] pointed out the importance of examining the upper tail of the incubation time distribution when assessing the quarantine period following exposure to smallpox. This was discussed in the context of the SARS coronavirus outbreak[7]. Both of these previous authors noted the importance of the distributional form in assessing the upper tail probability, and the influence that data truncation may have on such estimates

Summary

Introduction

To reduce the spread, it is necessary and desirable to quarantine each individual who might have been exposed for a sufficient time for either infection to occur or until it can be assured that there is not likely to be infection (and spread of contagion). Nishiura[6] pointed out the importance of examining the upper tail of the incubation time distribution when assessing the quarantine period following exposure to smallpox. Both of these previous authors noted the importance of the distributional form in assessing the upper tail probability, and the influence that data truncation may have on such estimates.

Objectives

Results

Conclusion