Infectious and autoimmune etiologies were investigated with complete blood count, C-reactive protein (CRP), erythrocyte sedimentation rate, antinuclear antibodies (ANA), blood culture, and serum analysis for antibodies directed against Treponema pallidum, hepatitis C, and tick borne diseases (Erlichia chaffeensis, Anaplasma, Babesia microti, and Borrelia burgdorferi) in addition to a Lyme antibody immunoblot test. This evidence concerns the gene CRP and hepatitis C virus infection.