c14_disease_dyn_handout

c14_disease_dyn_handout - 11/2/2009 1 Spreading Processes...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 11/2/2009 1 Spreading Processes Modeling Infectious Disease Dynamics with Networks What is epidemiology? Terms Susceptible Infected Epidemic Questions asked: will an epidemic occur? what is the typical size of an outbreak? what determines the probability of an epidemic? How do we control the spread? I dt dR I I IS dt dI IS dt dS =-- =- = S I R susceptible infectious recovered Compartmental models S I R susceptible infectious recovered Compartmental models R = Infection rate Mortality + Recovery rate Reproductive Ratio/Number: average number of secondary cases per infected individual 11/2/2009 2 Generation time 10 days SARS and its Reproductive Ratio (R0) Initial estimates for SARS: R 0 = 2.2 - 3.7 SARS spread unchecked in China for 120 days. 30,000-10,000,000 782 Days 10 20 30 40 120 R = reproductive ratio b number of secondary infections caused by a single infected person Ref: Meyers et al (2005) J Theor Biol. 2005 Jan 7;232(1):71-81 Whats missing in this model? nurse poet teacher infant S I R susceptible infectious removed Review: Compartmental Models Advantages :- Simple-Extendable- Amenable to mathematical analysis Disadvantage :- Assume everyone in the population is equally vulnerable to infection and to spreading infection. S I R susceptible infectious removed What can we do to fix this? 11/2/2009 3 Terminology Node (vertex): These represent people or places that can become infected Edge: contacts between nodes (people) that can lead to disease transmission Degree: The number of edges coming out of a node 1 3 2 6 CONTACT NETWORK (graph) What makes up a contact network?What makes up a contact network?...
View Full Document

Page1 / 9

c14_disease_dyn_handout - 11/2/2009 1 Spreading Processes...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online