A male patient 25 years age with occupation - labour stone quarry worker - living in a forest. Complaining of high-grade fever with chills and rigors. Nausea Body aches, headache since 3-4 days.

On investigation, Dengue, malaria - negative Widal negative Reduced WBC count: 3500/cmm Platelet WNL HB - WNL Not responding to cefotaxim 1gm bd for 3 days, Paracetamol 2gm per day, Still fever and chills and rigors episodes Chest x-ray clear. Please suggest probable diagnosis and management.