My Daughter Age 2and 1/2 Year Old Last Month She

my daughter age 2and 1/2 year old last month she got tyfyoid.dr tretment with mavirik injection for 5 days.but after 3 days my daughter has several time feel fever and pain in legs .when we give him panadol syrup the fever disapear but for one day or two day.I want to ask what causes of fever some weaknes or some remaing bacteria in her body.what should i do need some more test.