My husband suffering from on and off fever from 1

Patient: My husband suffering from on and off fever from 1 month all the reports like typhoid malaria cbp are normal and CRP is 38 and high fever and chills no other symptoms he will eat nicely and no constipation problem and gall stones in gallbladder and liver lightly enlarged his weight is 120 kgs height 5’11 age 30 he take alchole in parties what is the reason for fever

Doctor: