The summary at the top is the only part that needs reading, though the rest is informative too.
Basically, they don't know what it is yet, though given the malnourished, somewhat cut off, poor region with spotty healthcare at best, this could be one or multiple illnesses that we already know about, which have all struck a weak population at a bad time.
So, no need to panic just yet. They're sending various test samples off to be checked out, but the road out of the region takes 48 hours to drive due to rainy season issues, so it's a bit slow going.
All in all, this is likely no big deal, but certainly worth keeping an eye on just to be safe. These sorts of things happen all the time, basically, but before COVID nobody really cared.