The next 3 weeks are crucial in the fight against Ebola according to the Fred Hutchinson Cancer Research Center which is predicting 10000 cases by the end of September 2014. Several doctors and experts have contributed to their research which paints a bleak picture.
Several other organizations have modeled the outbreak and although the numbers are not consistent the message is clear, without significant intervention the virus could spiral out of control and the results would be catastrophic.
Another model predicts more than 12000 cases by the end of September using an R0 of 2. R0 is a basic reproduction number of an infection that is simply thought of as the number of infections created by a single infection. Influenza typically exhibits a R0 of between 2 and 3 as an airborne virus. Ebola R0 values are typically between 1 and 4. The 1995 outbreak in the Democratic Republic of Congo had an estimated R0 of 1.83.
Some quick and simple models using exponential curves based on current World Health Organisation data indicate 8000 cases by the end of September while the WHO itself has indicated that it expects more than 20000 cases before containing the epidemic.
Alessandro Vespignani from Northeastern University reached similar numbers predicting between 6000 and 10000 cases by the end of the month. He was quick to remind everyone that statistical predictions are not 100% accurate and unfolding events could change the results.
Scientific and statistical models are not without flaws and it is important to remember that these are typically “worst case” scenarios often modeled without GIS data or Regression and at best based on limited and possibly inaccurate data currently available.
These models are invaluable since they not only provide data for authorities to base decisions off of but also provide a comparison to previous Ebola outbreaks which form a large part of the modelling process.