Office Etiquette

I think I gave one of my co-workers the cold I had last week. The same cold I picked up from yet another co-worker, who had been out sick the week before with it. I feel really badly about my role as the little office carrier monkey, but I really couldn't stay home on account of the fact that I was mad busy with my own work and trying to cover another co-worker's work while she sunbathed in Hawaii. So. I want to say something like, "Hey, feel better" but I'm afraid this co-worker going to take the opportunity to yell at me for giving her my cold. But it seems really rude not to. Dilemma.