I'm really in no way qualified to comment on your experiences, only to sympathise in what must have been an unacceptable nightmare.
I'm only posting to say that in a distant recollection of when I worked for a large company pre '72, the only similar experience I remember, again Nigeria, the company doctor immediately had the patient, with similar symptons to those you describe, whisked off to a BUPA specialist tropical medicine unit, which presumably still exists. At the time we all thought it made the BUPA contributions seem cheap, and I can't remember opening an African operation being on the board room agenda afterwards!.

Thanks Boxer. My experience with Bupa has also been very good. My company is revising its malaria policy based on our experience to recommend where employees should go if they have a choice at the time. Hopefully, it will allow others to avoid the problems that we went through.