Training the Virus roller-coaster

Has anyone else had experience recently of a cold/flu virus that just keeps coming back? I can usually shake a cold in 3 days. This one I have had three times, each lasting about 5 days. It goes and I start feeling fine again, train without any apparent loss of form, then after a week its back and slightly stronger. I am now into day 6 of my third lay-off and I’m starting to feel about 90-95%. I plan on taking two more complete rest days and seeing how I feel. I have never been I’ll repeatedly ill like this before and I’m worried I may have caught glandular fever from a friend!!??