The Center for Disease Control has released a model projecting the possible worst case scenario for the current Ebola outbreak in West Africa. The virus has claimed more than 3000 lives this year already and is expected to progress rapidly in the absence of significant intervention.
The best case projections indicate containment of the virus by January 2015 predicated on the successful treatment of at least 70% of all cases, current and future. The worst case however indicates 1.4 million Ebola cases by the 20th of January 2014. The model takes a view that the current under-reporting of cases is significant as has been suggested by many experts in the preceding weeks.
The CDC was careful, reminding the public that although the model is scientifically sound, it is a worst case scenario which is unlikely to occur given the global mobilization to aid the West African region. The World Health Organization took a more conservative stance when releasing updated predictions indicating as many as 20000 cases by November 2014.
The data released by the CDC included positive news with regards to the isolation and treatment of Ebola patients confirming that the R0 value decreased significantly in isolated patients. As expected minimizing the potential contacts of an Ebola patient reduces the ability of the virus to spread. The worrying reality in countries like Sierra Leone and Liberia remains the infrastructure challenges of sufficient bed space and facilities to isolate patients to avoid forcing them to return home increasing the risk of a higher R0 value.
Guinea has been excluded from the model and many similar models of late as a result of unreliable data. Analysts have questioned the large variations in data between affected countries but particularly the fluctuating case data from Guinea. However, by extrapolating the current data and models provided by the CDC it is possible that 10% of the West African population will could have come into contact with Ebola by January 2015. The fears held by many and the warnings from MSF earlier this year have suddenly taken on new meaning in light of recent predictions by the CDC and WHO.