Running this site is a constant reminder of my geographical ignorance. Until about a week ago, I had never bothered my pretty little head for a moment about Guinea or any other West African nation. While I've learned a bit, I'm still much more in a "Duh" moment than an "Aha!" epiphany.
But some new stories have pointed out that this is Guinea's first encounter with Ebola, and if you look at a map of Africa, you realize that it's an encounter with implications.
The last reported Ebola outbreak was in Uganda in 2012. But that was the SEBOV strain; Guinea is dealing with ZEBOV, which saw its last outbreak in late 2008 and early 2009 in Kasai Occidental, whose capital, Kananga, is some 6,811 km by road from Conakry. No doubt some determined, asymptomatic bat or chimp might get there more directly, but it's still a remarkably long way.
The implication is that Ebola has migrated (or is quietly endemic) in almost every country with forest habitat between the DRC and Guinea: I would assume that includes Congo-Brazzaville, Gabon, Cameroon, Nigeria, Benin, Togo, Ghana, Cote d'Ivoire, and Liberia.
I suppose it's possible that some enterprising bushmeat wholesaler in Kasai Occidental actually flew a shipment of Ebola-infected product all the way to Conakry and then trucked it to southeast Guinea, where Ebola suddenly began a new career as a successful immigrant. But it's not possible enough to build a plausible scenario around.
More likely Ebola has spread quietly through host animal populations from country to country, minding its own business and rarely infecting humans. Even those cases might go unnoticed and unreported. Only in southeast Guinea did a combination of circumstances permit extensive infections and a rapid spread.
Maia Majumder, an MPH and engineering systems Ph.D. student at MIT, has posted some interesting thoughts about Ebola's travels. (I've added her site to the Bloggers list.) She speculates on good evidence that migrating bats, deprived of their normal habitat by deforestation in the DRC, have moved into West Africa. Majumder notes that human Ebola outbreaks tend to occur when the Ebola rate in bats is around 5%. At that rate, some unlucky bat is going to end up literally in the soup, with the consequences we now see.
This path from the DRC to Guinea is still a conjecture, but it's the most persuasive one I've seen yet.