Fever, Rash, and Migratory Polyarthralgias

A 24-year-old farmworker had 3 weeks of persistent fever and worsening polyarthralgias, and maculopapular truncal rash that spread to her palms and soles. Results of laboratory tests were normal except for a mildly elevated WBC count and a blood culture gram stain showing filamentous gram-negative rods. What would you do next?
Source: JAMA - Journal of the American Medical Association - Category: General Medicine Source Type: research