Modeling the Ebola Outbreak in West Africa, February 24th 2015 update

DRAFT – Not for a.ribu2on or distribu2on

Modeling the Ebola Outbreak in West Africa, 2014

February 24th Update

Bryan Lewis PhD, MPH ([email protected]) presen2ng on behalf of the Ebola Response Team of

Network Dynamics and Simula2on Science Lab from the Virginia Bioinforma2cs Ins2tute at Virginia Tech

Technical Report #15-‐016


NDSSL Ebola Response Team Staff: Abhijin Adiga, Kathy Alexander, Chris Barre., Richard Beckman, Keith Bisset, Jiangzhuo Chen, Youngyoun Chungbaek, Stephen Eubank, Sandeep Gupta, Maleq Khan, Chris Kuhlman, Eric Lofgren, Bryan Lewis, Achla Marathe, Madhav Marathe, Henning Mortveit, Eric Nordberg, Paula Stretz, Samarth Swarup, Meredith Wilson,Mandy Wilson, and Dawen Xie, with support from Ginger Stewart, Maureen Lawrence-‐Kuether, Kayla Tyler, Bill Marmagas Students: S.M. Arifuzzaman, Aditya Agashe, Vivek Akupatni, Caitlin Rivers, Pyrros Telionis, Jessie Gunter, Elizabeth Musser, James Schli., Youssef Jemia, Margaret Carolan, Bryan Kaperick, Warner Rose, Kara Harrison 2


Currently used data (as of Feb 18th, 2014)

●  Data from WHO, MoH Liberia, and MoH Sierra Leone, available at h.ps://github.com/cmrivers/ebola

●  MoH and WHO have reasonable agreement ●  Sierra Leone case counts censored up

to 4/30/14. ●  Time series was filled in with missing

dates, and case counts were interpolated.

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Cases Deaths Guinea 3,108 2,057 Liberia 9,007 3,900 Sierra Leone 11,103 3,408 Total 23,253 9,380


Liberia infec2on rate

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Liberia Forecast

5

1/13 -‐

1/19

1/20 -‐

1/26

1/27 -‐

2/02

2/03 -‐

2/08

2/09 -‐

2/16

2/17 -‐

2/23

2/24 -‐

3/02

Reported 3 5 3 3 0

Updated model 1 6 4 2 7 4 2

Reproduc2ve Number Community 0.3 Hospital 0.3 Funeral 0.2 Overall 0.8


Liberia-‐ Prevalence

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Date People in H + I

2/2 21

2/9 13

2/16 7

2/23 4

3/02 1

3/09 1


Sierra Leone infec2on rate

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Sierra Leone Forecast

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35% of cases are hospitalized

ReproducNve Number Community 0.7 Hospital 0.2 Funeral 0.1 Overall 1.0

1/13 -‐

1/19

1/20 -‐

1/26

1/27 -‐

2/02

2/03 -‐

2/08

2/09 -‐

2/16

2/17 -‐

2/23

2/24 -‐

3/02

Reported 84 56 30 51 42

Updated model

81 67 55 44 36 30 24


Sierra Leone-‐ Prevalence

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Date People in H + I

2/2 112

2/9 92

2/16 76

2/23 63

3/02 51

3/09 42


Guinea Forecasts

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40% of cases are hospitalized

ReproducNve Number Community 0.25 Hospital 0.09 Funeral 0.01 Overall 0.36

1/13 -‐

1/19

1/20 -‐

1/26

1/27 -‐

2/02

2/03 -‐

2/08

2/09 -‐

2/16

2/17 -‐

2/23

2/24 -‐

3/02

Reported 32 13 16 14 65

Updated model

37 27 18* 12* 5* 4* 2*

* too small for reliable forecas2ng


Guinea Prevalence

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Date People in H+I

2/2 53

2/9 35

2/16 23

2/23 15

3/02 10

3/09 6


Compartmental Model Forecasts

•  Development of more nimble stochas2c but compartmental models for forecas2ng

•  Dynamic manipula2on of behavioral changes poses a challenge for most solvers, but techniques exist –  S2ll working out the kinks

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“Cones of uncertainty”


Update on Vaccine Trials

•  Advantages –  Focuses energy on contact tracing which is appropriate without a vaccine trial going on

–  Es2mated that a dozen or so rings like this may provide sufficient power for reasonable efficacy es2mates

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Suscep2ble

Infected

Vaccinate now

Vaccinate later

•  New hybrid trail design to be tried –  Not stepped wedge but a

cluster-‐based approach that randomizes when vax is received by contacts

–  Timing: immediate or 21 days –  Star2ng next week in Guinea


Early vaccina2on study ObjecNve: Assuming that early deployment of vaccine interven2ons, what vaccine stockpile is necessary to control a reasonably stressful outbreak like the 2014 West African outbreak?

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Early Interven2on Design

Disease: Calibrated to Liberia (explosive growth) IntervenNon sweep: every 2 weeks, June thru July Doses: 1k, 2k, 5k, 10k Case finding: 100%, 80%, 50% Compliance: 25%, 50%, 75% Ring VaccinaNon: Assume all contacts can be found (thus 100% compliance means all contacts have been found and vaccinated) Efficacy: 50%, 80%

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APP UPDATE Eyes-‐on-‐the-‐Ground

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Eyes-‐on-‐the-‐Ground: Overview Road condi2ons in West Africa can vary day to day. Eyes on the Ground allows witnesses on the ground to record what they see through an easy-‐to-‐use web interface.


Eyes-‐on-‐the-‐Ground: New Features

•  Added Sierra Leone –  Ini2alized with GIS calculated es2mates of travel 2me

•  Query-‐able interface added – Summary of previous responses instantly available on main screen upon origin-‐des2na2on selec2on

•  GUI improvements and browser support

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Step 1: Select a country.

Step 2: Enter the details of your report. No2ce that you can see when the route was last reported on, what the last user reported, and the mean travel dura2on

for the last 5 trips.



Travelers can view past reports from the website in order to plan the best route to medical help or for delivering supplies.

h.p://ebola.vbi.vt.edu/eyesontheground/