CRP and infective endocarditis: Patients must be evaluated to rule out NVO in the following conditions: (a) new or worsening back or neck pain and fever, (b) new or worsening back or neck pain and elevated erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP), (c) new or worsening back or neck pain and bloodstream infection or infective endocarditis, (d) fever and new neurologic symptoms with or without back pain, and (e) new localized neck or back pain, following a recent episode of S. aureus bloodstream infection.