Talk to General Physician on Continously Fever

Assalam u alaikum One week before my mother had suffered from 105 fever... There there was intense pain in her lower back and she feel pain when she pass urine..... Doctors said she has kidney infection.... She is recovering but the problem is tha she is suffering from fever from one week continously... She feel relax when take madicine but after sometime facing same condition of fever..... Plz suggest some proper treatment.... Jazakallah