For those of you that follow me on Twitter, you may have noticed a restless night of non-stop tweeting re: the Ebola outbreak currently taking place in West Africa. This is unfolding right before our eyes, guys. Terrifying, but it’s incredible how social media allows us to see exceedingly rare and horrifyingly remarkable events come alive in real time around the world.
Before moving onto the more intriguing details of this impending global health crisis, let’s start off with some background information on Ebola:
1. The disease “Ebola” is caused by 5 different Ebolaviruses [EBOV]; 4 of them demonstrate pathology in human beings. Of these 4, Zaire ebolavirus [ZEBOV] is the most fatal – with recorded case fatality rates (CFR) of up to 90%. Historically, Ebola outbreaks have taken place in Central Africa. The ZEBOV strain in particular can only be classified as such if it is endemic in the DRC, Gabon, or Republic of the Congo.
2. Individuals infected with Ebola may suffer from severe hemmoraghing, but the usual cause of death is multiple organ dysfunction.
3. Ebola is considered a “zoonotic” disease; it finds its origins in bat reservoirs. Sounds a bit like Contagion, doesn’t it? (That’s no coincidence.)
Terrestrial mammals (gorillas, chimps, etc.) often serve as intermediaries between asymptomatic bats and humans. When bats drop infected fruit, land animals consume it; unlike the bats, they often die from contracting the virus. In handling the highly infectious carcass of the intermediary animal, Ebola transmits into the human population. The current Ebola outbreak is a poignant reminder of how the gap between humans and other species is ever-shrinking. If there was ever a case to be made for OneHealth research, this is it.
So, what’s so interesting about this particular outbreak?
1. The CFR is extremely high. Some of the most recent reports are quoting 59 deaths out of 80 likely cases. That’s nearly 75%. Moreover, preliminary sequencing of current outbreak samples show strong homology with ZEBOV. Between this and the staggering mortality that’s already emerged from this outbreak, I think that ZEBOV is a pretty likely culprit. However, because of the high CFR, the handling of these highly infectious bodies will need to be managed very carefully; otherwise, we are bound to see an ever-increasing incidence of disease.
2. Assuming the ZEBOV is to blame, I can’t help but wonder how it got to West Africa in the first place. Could this potentially mean that the endemic region of the ZEBOV strain is growing beyond its original stomping grounds in Central Africa? And if so, where will it spread to next? Not to mention, what’s responsible for this geographic “expansion” and/or “leap”? Has ZEBOV become more robust genetically? And in that case, should we expect a higher-than-average case mortality?
3. Finally, because of the zoonotic nature of the disease, Ebola is traditionally found in forested – rather than urban or peri-urban – regions. However, as of 3/27/14, cases from this particular outbreak have surfaced in Conakry – the capital city of Guinea. It also seems to have spread to Sierra Leone as well as Liberia, and it is possible that it will progress into other neighboring countries. This is particularly alarming for the following reasons:
a. While quarantining a small forested community is challenging, quarantining a capital city with an international airport is impossible.
b. After contracting the virus, it may lie dormant for up to 21 days. An infected individual may very well feel well enough to fly.
c. I think we all know what may come next. Gwyneth Paltrow’s character coming home from China, anybody? (And no, there are no travel bans or advisories… Not yet, at least.)