What Causes Severe Fever,sweats And Body Aches?

My husband suffered from a bout of flu commencing July 29th 2011 while in Rome at the start of our holiday, we had been there for 2 days. He had all flu like symptons and we presumed given a few weeks he would return to normal. This has not occured. Ongoing symptions include aches and pains in joints which seem to travel to different spots in his body but regularly in his hands. High temperatures and severe sweats. General tiredness and feeling unwell with the occasional bloating and stomach pains. Unable to perform a normal days activity and spends much of his day laying on a bed. He has had 4 separate sets of blood test, for varies virus including Ross River and Bahman Forest Virus. All blood tests have not provided any indication or resolution to the problem. He spend 2 nights in hospital this week with a suspected heart attack, but his heart is strong and blood pressure excellent. He is under our local GP however there is no help other than to say it takes time . His symptons of fevers, sweats, tiredness and aches seem to be worse now rather than better after nearly 6 months. Please help