Chapter 8 SIR Models

So=9998 Io=2 Ro=0 duration of Infection= 2 days Recoveries=(Infected Population)/(duration of infection) Can use summer for Affected population

Infectivity (rate)=0.25 per contact Contacts per day=6 per infected person Total contact per day=6 * Infected Population Recoveries per day =Infected population / infection duration

Sensitivity Analysis Contact number = (infectivity) (contacts per day) (infection duration) Sometimes referred to at Ro the reproductivity number (The number of new infections) / (a single infected person) R>1 epedemic R<1 disease dies out

Sensitivity run Infectivity=1-50% 2-25% %

Sensitivity run Infection duration = 1-4 days 2-2 days 3-1 day

Policy analysis What can we do??

1918 influenza pandemic 50 to 100 million died worldwide

1918 Influenza: the Mother of All Pandemics Jeffery K. Taubenberger* and David M. Morens Emerging Infectious Diseases Vol. 12, No. 1, January 2006www.cdc.gov/eid