I'm not a geneticist, but it seems somewhat pedantic to be arguing whether it's a new strain of Ebola Zaire or a new strain of ebola related to Ebola Zaire. The point is that the strain in West Africa is significantly different (both genetically and observed in patients) from previously detected strains in Central Africa, but shares a common ancestor with Ebola Zaire - there's no debate on either of those points that I'm aware of.
Oh, I agree about the pedantics of phylogenetics at some point.
It’s not really that different observed in patients however. The difference in reported CFR seems to be different merely because many tested cases don’t subsequently get treated or die and become recorded as deaths. Plus the outbreak is still going exponential there so there are many recently infected that simply haven’t had a chance to kick off just yet.
But there was an article (from msf? maybe) that indicated that of the cases that had actually *resolved* that there was not quite 90% CFR with this outbreak.
Genetically it looks like zebola has just drifted a bit since we first encountered it in ‘76.
At some point phylogenetic tree and classification becomes like angels dancing on the head of a pin. I learned long ago that if a geneticist made up his/her mind about a particular branch to let them LOL.