my neighbour male/40 year no sloking/occ alcohol ,having fever with chills 3 to 4 episode per dayfor last 3 days,also have frontal headace, severe bodyace ,h/o opd and on brochodilator,and physician given cefaperazone,levoflox,expetorant ,febrinil,diclofenac ,but fever continoue for 3 days 102-104 degree, cbc ,psfomyp,widal urin test normal .what are the possible cause and what to do next ???