Aggravating both the financial and social consequences, these countries and their frightened African neighbors are enacting concentric circles of quarantines, cutting off neighborhoods, regions and even whole nations.
But those reactions are exacerbated by the way that those local economies work. The first is that they're still, by even historical standards, very poor places. That means that trade is still done, largely, by an individual actually going somewhere and choosing something, then returning it and trading it on. That is, trade and economic activity still depend largely on the movement of those traders. Quarantines and restricted areas are not just limiting the movement of people they're also strangling even the low level of trade that happens. The second is that a lot of recent economic growth has come from trade across the local borders. This is something that economists have been complaining about for decades now: the way in which there's so little intra-African trade. It's rather a memento (and a pernicious one) of colonialism: that just as the Imperial and colonial nations used to trade between the "home" country and the various colonies so too those colonies have their trade oriented outwards to those former colonial powers. We in Europe rather changed that as we built the European Union (for better or worse in the general sense) and deliberately encouraged more intra-European trade. The same didn't really happen in Africa. States were left trading very little with the country next door and a great deal more still with Europe or other richer countries.
This has infuriated economists for decades and it's really only in the last 10, 15, years that this has been changing,. There's now a lot more trade across those local West African borders than there ever used to be: that's one of the reasons why growth prospects have been so good.