Modeling the Ebola Outbreak in West Africa, 2014 August 19 th Update Bryan Lewis PhD, MPH Caitlin Rivers MPH, Eric Lofgren PhD, James Schlitt, Katie Dunphy, Stephen Eubank PhD, Madhav Marathe PhD, and Chris Barrett PhD
Currently Used WHO Data CasesDeaths Guinea Liberia Sierra Leone Nigeria165 Total ● Data reported by WHO on Aug 22 for cases as of Aug 20 ● Sierra Leone case counts censored up to 4/30/14. ● Time series was filled in with missing dates, and case counts were interpolated. 2
Epi Notes – WHO reports Unsettling Underestimation assessment – Significant undercounting of cases suspected Lots of fresh graves in villages with no reported cases ETCs overwhelmed in hours, non-ETC triage centers getting flooded with patients Large swaths of areas blockaded off with rumors of infections Healthcare worker impact august-2014/en/ august-2014/en/ – 240 HCW infected, 120 dead – Depleting the workforce, estimate 1-2 docs /100K pop – Liberian doctor Borbor dies after Zmapp Rx – First WHO HCW infected (Brit already back in UK) 3
Epi Notes Travel restrictions (flight bans) increasing – Limiting WHO’s ability to bring in staff – Addressing a very small risk and counter productive WHO tweet – 100 more confirmed cases than previously reported as of 8-20 (16 additional deaths) – Maybe a reporting artifact from more tests 4
Epi Notes Outbreak in DRC – Dozen or so suspected cases a couple confirmed positive – Confirmed evidence that it is NOT related to West African outbreak, different strain Supplies are arriving! – 16 tons of USAID supplies ) ) – 68 tons of UNICEF supplies ( – Many other smaller ones like: 30k lbs from Fort Worth 5
Tweet volume 6
Liberia Forecasts 7
rI: 0.95 rH: 0.65 rF: 0.61 R0 total:
Liberia Forecasts 9 8/6 – 8/12 8/13 – 8/19 8/20 – 8/26 8/27 – 9/02 9/3 – 9/9 Actual Forecast
Liberia Vaccinations 10
Liberia – Better Isolation 11
Liberia – Better Contact Tracing 12
Sierra Leone Forecasts 13
Sierra Leone Forecasts rI:0.85 rH:0.74 rF:0.31 R0 total:
Sierra Leone Forecasts 15 8/6 – 8/12 8/13 – 8/19 8/20 – 8/26 8/27 – 9/02 9/3 – 9/9 Actual Forecast
Sierra Leone Vaccinations 16
Sierra Leone – Better Isolation 17
Sierra Leone – Better Contact Tracing 18
All Countries Forecasts 19 rI:0.85 rH:0.74 rF:0.31 Overal:1.90
Guinea, Sierra Leone, and Liberia 20 8/3 – 8/9 8/10 – 8/16 8/17 – 8/23 8/24 – 8/30 8/31 – 9/6 Actual Forecast
Why now? What is different Role of chance not to be discount – Running expt to look at expected outcome in this pop 21
Next Steps Data pouring in: – Landscan – Tribal Distributions – Road networks – Procedural info for delivery of care and diag etc. Initial version of Sierra Leone constructed – Tests to verify and validate – Begin simulations Build similar versions for other affected countries 22
Next Steps Mobility data from Flowminder – Under Analysis to compare with our estimates 23
Next steps Publications – One planned for submission – 2 quick communications in prep Problems appropriate for agent-based approach – Logistical questions surrounding delivery and use of medical supplies – Effects of limited HCW both direct and indirect – Synthetic outbreaks to compare to what we’ve observed of this one, to estimate true size 24