Recurrent fever. And it's minus 7 here.

5 days ago , I had fever 102. For at least 8 days with chills and extreme fatigue,then I did CBC widal dengue malaria ,flu test everything came normal, doctor put me on dolo 625 and levofloxcin tab . I started recovering well after 8 days but yesterday night around 10 pm I checked my fever it was again up 99.9, I had become very weak also , look like as if I had lost come weight ,may be due to the profuse swear which used to come after taking DOLO . I also did a urine test ,it show a little bit infection not that much . I already took levofloxcin for 10 days now along with dolo . Please suggest something . What can be the cause of recurrent fever . My sister 18 years old also had the same symptoms. But she is doing well now, from one two days , I am in Kashmir and it's minus 7 here .