Lyme disease and related tick-borne illnesses

Our knowledge of lyme disease, currently the most common vector-borne illne ss in North America, has expanded over the, past decade. The causative spir ochete, Borrelia burgdorferi is transmitted by the bite of an infected Ixod es tick. Infection usually results in erythema migrans and can spread hemat ogenously to skin, heart, nervous system, joints, and other organs. Prompt recognition and treatment with antibiotics usually leads to rapid improveme nt and markedly reduces subsequent manifestation. Unrecognized and untreate d Lyme disease can cause late-arthritic and neurologic syndromes that are m ore difficult: to treat and that may not respond to antibiotics. Other tick -borne illnesses can be fatal if not treated.