Bacterial infections can clinically mimic a primary vasculitic syndrome and can directly cause a vasculitis that may respond to prompt recognition and treatment of the infection. Increasing direct and indirect evidence is establishing links between certain infections and vasculopathies, including aortitis, atherosclerosis, and Wegener's granulomatosis. The literature on the hepatitis viruses, particularly hepatitis C, and various vasculitic syndromes continues to grow. The spectrum of clinical syndromes, including "essential" cryoglobulinemia (elicited by the hepatitis viruses) and HIV, continues to broaden. Clinical trials have begun to demonstrate the therapeutic value of antiviral therapy in patients with these conditions.