30 year male with fever since last 3 months with musculoskeletal pain, nasal congestion since 1 month with mild sputum and no cough. Investigations- widal & MP negative, Lymphocytosis seen, Platelets normal, EsR raised, T/t- 2 weeks cefixime, 1 week Azithromycin and Cefpodoxime , 2 weeks cefpodoxime axetil.

Still no relief. What could be the probable diagnosis and further management?