The Rules of Contagion

Meltzer M.I. et al., ‘Estimating the Future Number of Cases in
the Ebola Epidemic – Liberia and Sierra Leone, 2014–2015’,
Morbidity and Mortality Weekly Report, 2014.

The CDC exponential model estimated around a three-fold
increase per month. Therefore a prediction three additional
months ahead would have estimated 27-fold more cases than the
January value. (The combined population of SL, Liberia and
Guinea was around 24 million.)

‘Expert reaction to CDC estimates of numbers of future Ebola
cases’, Science Media Centre, 24 September 2014.

Background from: Hughes M., ‘Developers wish people would
remember what a big deal Y2K bug was’, The Next Web, 26
October 2017; Schofield J., ‘Money we spent’, The Guardian, 5
January 2000.

https://twitter.com/JoanneLiu_MSF/status/952834207667097600.

In the CDC analysis, cases were scaled up by a factor of 2.5 to
account for under-reporting. If we apply the same scaling to the
reported cases, this suggests there were around 75,000
infections in reality, a difference of 1.33 million from the CDC
prediction. The suggestion that the CDC model with interventions
could explain outbreak comes from: Frieden T.R. and Damon I.K.,
‘Ebola in West Africa – CDC’s Role in Epidemic Detection,
Control, and Prevention’, Emerging Infectious Diseases, 2015.

Onishi N., ‘Empty Ebola Clinics in Liberia Are Seen as Misstep
in U.S. Relief Effort’, New York Times, 2015.

Kucharski A.J. et al., ‘Measuring the impact of Ebola control
measures in Sierra Leone’, PNAS, 2015.

Camacho A. et al., ‘Potential for large outbreaks of Ebola virus
disease’, Epidemics, 2014.

Heymann D.L., ‘Ebola: transforming fear into appropriate
action’, The Lancet, 2017.