"The doctors have been unable  to diagnose the disease but they suspect
that it could be some serious kind of tropical disease as he had been
to Nepal last summer."

oh yeah americans doctors blaming Nepal now. WTF!
first they can't even diagnose what kind of disease,....!!
i wonder what kind of education they received there???

When your friend was in Nepal he was fine. It's only after he was in USA he became sick.
what does this shows.

Anyway what is your friends ethnicity?
i suggest you call dami or  Jankgri ba. it could be kul dewta, jungleli spirits.
some ethnicity praticed shaminism, and this could be a link to doctors not finding
what was the problem.
skh