Centers for Disease Control and Prevention
CDC Home Search Health Topics A-Z
peer-reviewed.gif (582 bytes)
eid_header.gif (2942 bytes)
second_navbar.gif (585 bytes)
 
Research

Modeling Potential Responses to Smallpox as a Bioterrorist Weapon

Martin I. Meltzer,* Inger Damon,* James W. LeDuc,* and J. Donald Millar†
*Centers for Disease Control and Prevention, Atlanta, Georgia, USA; and †Don Millar & Associates, Inc., Atlanta, Georgia, USA

Figure 1. Schematic of the Markov-chain model used to model the movement of a person infected with smallpox through the four stages of disease. PI = probability of remaining in the incubating stage; PP = probability of remaining in the prodromal stage; and PO = probability of remaining in the overtly symptomatic stage. For each stage, the probabilities of remaining in that stage (PI,PP,PO) are determined by a daily probability (Figure 2). Patients who have reached the fourth and final stage (no longer infectious) effectively drop out of the model. The "overtly symptomatic" stage refers to the period of disease when a person has a rash or similar symptoms that even an untrained observer can readily note. During the period of infectivity, the average number of persons infected per infectious patient is preset by the researchers. The days when transmissions occur are determined by a probability function.

Back to article
Figure 1. Schematic of the Markov-chain model used to model the movement of a person infected with smallpox through the four stages of disease. PI = probability of remaining in the incubating stage; PP = probability of remaining in the prodromal stage; and PO = probability of remaining in the overtly symptomatic stage. For each stage, the probabilities of remaining in that stage (PI,PP,PO) are determined by a daily probability (Figure 2). Patients who have reached the fourth and final stage (no longer infectious) effectively drop out of the model. The "overtly symptomatic" stage refers to the period of disease when a person has a rash or similar symptoms that even an untrained observer can readily note. During the period of infectivity, the average number of persons infected per infectious patient is preset by the researchers. The days when transmissions occur are determined by a probability function.
 


Home | Top of Page | Current Issue | Expedited | Upcoming Issue | Past Issue | EID Search | Contact Us | Accessibility | Privacy Policy Notice | CDC Home | Search | Health Topics A-Z

This page last reviewed December 08, 2001

Emerging Infectious Diseases Journal
National Center for Infectious Diseases
Centers for Disease Control and Prevention