Can fever from Type A Flu last for up to days?

Last Thursday,2/5 my husband was diagnosed with Bronchitis & Tpye A Flu, ...rec'd Antibiotic for Bronchitis & appeared to recovered from that but by this past Thurs. 2/12, was back to having a fever of 99.+, went back to the Dr., rec'd a different antibiotic, & was told the flu just needed to run it's course,... but has had a fever yesterday & today of up to 101.6. He isn't coughing, stuffy nose, no headaches, isn't nauseated or having diahhrea, no difficulty in breathing, or congestion or sinus pain,...just says his skin feels very sensitive and is miserable when his fever goes up, & feels very fatigued. Also has nightsweats, needing to change his t-shirt, up to 3 times a night.