What Causes Fever Surges, Weight Loss And Diarrhea?

Hello, I'm asking a question for someone else, and it's not a shiness thing. My fiancee is in Europe right now, she has got symptoms that makes both of us nervous. The symptoms are:

- 38 degrees (Celsisus) to 38.8 degrees (Celsius) sudden fever surges;

- Especially in the morning and evening;

- Has been lasting for ten (10) days;

- Complained of slight weight loss;

- Had diarrhea for the first 2 days.



The context is:

- Just back from a humanitarian field mission in Central African Republic (6 months);

- Has taken antimalaria profilaxis regularly;

- Was taking the pill continuously to prevent her period because the place was very infection-prone;

- Has had blood tests, hospitalized in Norway for 3 days, HIV, epathitis, Mono, malaria all negative, liver indicators a little higher than normal.