Remedy for prolonged fever(post operative byp surgery)?

My brother underwent a byp surgery during march this year. After a week he developed high fever and subsequently he was diagonized for Endocarditis and treated with vancomycin. After 15 days the symptoms were no more.(by TEE) still he was having fever. Then he was diagonized for Miliary tuberculosis and treated with Streptomycin, INH, Zancocin and combutol. The intensity of fever reduced(by Dolo 650) but the fever keeps coming for twice or thrice a day. Help me resolving this.