More on the Ebola West African epidemic from the WHO Ebola Response Team

The WHO Ebola Response Team has reported in the September 23 issue of the New England Journal of Medicine its analysis of 3343 confirmed and 667 probable Ebola cases collected up to September 14 in 4 of the 5 West African countries to have experienced

Ebola virion CDC Public Health Image Library

cases of Ebola Virus Disease: Guinea, Liberia, Nigeria, and Sierra Leone. The team reports a typical age range of 15-44 years with no difference in gender of those affected. Its estimate of case fatality rate is higher than that noted by the Centers for Disease Control at 71% for people for whom the outcome their infection is known. Based on the number of cases to date, from this they estimate a 95% confidence interval [CI] of 69 to 73% for mortality risk.  The team notes that features of the disease, including a typical incubation period of 11 days to be similar to that for  previous outbreaks. Based on the initial periods of exponential growth of the outbreaks, they have modelled the doubling times are EVD to be 16 days for Guinea, 24 days for Liberia, and 30 days for Sierra Leone, with by November 2 the cumulative reported numbers of confirmed and probable cases predicted to be "5740 in Guinea, 9890 in Liberia, and 5000 in Sierra Leone", i.e. over 20,000 total cases for this EVD epidemic.

The CDC update to 25 September notes a case count for EVD of 6263, with 2917 reported deaths and 3487 laboratory confirmed cases.


More on the Ebola Virus Disease epidemic in West Africa

Information on Ebola virus from the Centers for Disease Control and Prevention