What Causes Persistent Fever And Neck Pain?

Question : my mother is 84. about a month ago, she was put on Cipro antibiotic to treat a cold-like illness with fever (102). It seemed to work and she completed the med-cycle to completion. Probably not related, but about 10 days ago, she started getting muscle aches in legs, back, neck, etc. No other symptoms. Then about 6 days ago, a mild fever (+1 or 2 degrees). Ibuprofin worked well for the aches, except her neck, which is quite achy. She switched to Tylenol for the fever, and also works, but a mild fever each night persists as well as a very sore neck... She was put on a pennecilin derivative last Friday, but since no change, was put on another Cipro (5 days worth) regime last night...nothing seems to be making any difference. What could this be? We live in Hawaii, and there is no lyme disease out here....

Yes, I had discussed this with her family care doctor yesterday. Blood and Urine tests had been taken last week. I was told, that it was not Menengitis, and there are no other symptoms at all, no nausea, fever is mild and does go away most times during the daytime, no sensitive to light, etc.... Could there be other possibilities?