Ebola II - The Scare

Unlike other recent "epidemic" scares like avian flu and H1N1, Ebola is not spread by respiratory or airborne mechanisms. It is spread by contact with bodily fluids such as blood, vomit, and diarrhea. This tells us who will be at highest risk: healthcare workers. I don't suspect that the general public will be at great danger for getting Ebola, but practitioners doing invasive procedures or caring directly for sick patients will be vulnerable. In the study of epidemics, a variable called R0 describes how infective a disease is; that is, how many people each infected person is likely to further infect. Compared with other diseases like measles, Ebola's estimated R0 is quite low, somewhere between 1.5 and 2. We have to decrease this below 1 to ensure a disease will be eradicated.

Lastly, Ebola is scary for many reasons. Its current case-fatality rate (what I think of as mortality rate) is estimated somewhere between 60-90% meaning the vast majority of patients who got it have died. But this is in the context of a developing country with limited physicians and resources trying to deal with a disease that's incompletely characterized. I imagine that the case-fatality in a developed country with adequate provisions will be much lower. The treatment is supportive, like most of what we do in the intensive care unit; there are no proven antivirals or miracle drugs, so fluid hydration, blood pressure and oxygen support, and blood transfusions are the mainstay of therapy. The other reason Ebola scares people is its name; it is the stuff of outbreak horror movies. I have talked to many people who are panicked about Ebola but my prediction is that this outbreak will take far fewer lives than influenza will this winter season, but will get much more press.

Image of nurses caring for a patient with Ebola from a 1976 Zaire outbreak is in the public domain, from Wikipedia.