1. Biological Attack Model(BAM)Progress ReportMarch 8 Sponsor: Dr. Yifan Liu Richard Bornhorst Robert Grillo Deepak Janardhanan Shubh Krishna Kathryn Poole

2. Agenda • Project Plan • Work Breakdown • Biological Agent Parameters • Assumptions Revisited • Preliminary Model Overview • Current Modeling Issues

3. Project Plan

4. Work Breakdown • 320 of 875 man-hours completed. • Ahead of schedule on modeling • End modeling phase by next brief to give an extra week to testing, evaluation, analysis, and recommendations (4 weeks) • Develop early skeleton for final report

5. Biological Agent Parameters • Smallpox (β = 3) (d = 30%) • Incubation Period: 7-17 days • Prodrome Period: 2-4 days • Symptomatic Period: 20 days • Ebola (β = 1-2) (d = 40%-90%) • Incubation Period: 2-20 days • Prodrome Period: 2-4 days • Symptomatic Period: 6-9 days • Viral Encephalitis (β = 3-4) (d = 3%-60%) • Incubation Period: 5-15 days • Prodrome Period: 2-4 days • Symptomatic Period: 7-14 days

6. Assumptions Revisited • Attack Assumptions • Single source where a certain number of people are initially exposed • Diseases will be transmitted person to person rather than airborne or food borne • Detected 24 hours after incident (may adjust for future analysis) • Population Assumptions • Constant population with no immigration/emigration, births, or deaths that aren’t related to the disease • People in the incubation stage (non-contagious) are considered susceptible in terms of quarantine and treatment since they are not yet known to be infected

7. Assumptions Revisited • Quarantine Assumptions • Various percentages of the population are quarantined to analyze effectiveness • Isolation of confirmed and suspected cases with vaccination and quarantine of contacts traced to these cases • All other quarantine is voluntary confinement • A percentage of the population cannot be quarantined • Vaccination and Treatment Assumptions • A percentage of population is already vaccinated (when applicable) • Emergency response and medical staff already vaccinated (if available) • Treatments are available for recovering those that receive it • Vaccination and treatment have no significant side effects • Those in quarantine without symptoms receive available vaccination • Those showing symptoms do not receive vaccination (treatment only)

8. Two Phases • First Phase • The spread of the pathogen before detection • Initial assumption is detection occurs after 24 hours, but this will be adjusted to analyze the importance of early detection • Only three states during this phase: Susceptible, Infected, Infectious • Second Phase • Occurs after outbreak has been identified • The status of states at end of first phase provide initial conditions for second phase • Containment strategies employed

9. Preliminary Model Diagram Track 10 different populations S+Qi1+Qi2+Qs+I1+I2+RN+RT+RD+D = N Recovered With Treatment RT Quarantined Infected Qi1 Susceptible S Infected I1 Quarantined Infectious Qi2 Dead D Quarantined Susceptible QS Infectious I2 Disabled RD Recovered Without Treatment RN

10. Preliminary Model Parameters • Transmission Rate (b) • Average Incubation Length (m1) • Average Infectious Length (m2) • Disease Mortality Rate (d) • Quarantine Rate (q) • Tracing Close Contacts of Infectious (a) • Number of Treated Per Day (f) • Treatment Efficacy Period (b) • Disability Ratio (g) • Total Population (N)

11. Preliminary Model Parameters (Excel snapshot)

12. Example Plot:10,000 treated per day, 30% Quarantine Rate

13. Example Plot:10,000 treated per day, No Quarantine

14. Example Plot:20,000 treated per day, 30% Quarantine Rate

15. Current Modeling Issues • Modeling a Coherent Detection Scheme • Disease incubation periods vs. appearance of symptoms • Arriving at a Balance between Number of States & Reality • Risk of Inaccuracy vs. simplification • Recovery without treatment, Side effects…. • Integrity checks to be built in • Containment as a combination of Reducing Contacts and Treatment Resource Allocation • Effective Treatment allocation issue • Availability of Emergency Responders • Effect of varying β due to Intervention efforts • Diverse Containment strategies emerging for different diseases • More data available on Smallpox than the others • Translating results into Information for a Decision Maker • Use of percentages of population vs. absolute numbers

16. Questions ?