Lyme Disease and other Tick-Borne Diseases

Aetna covers an initial 4-week course of outpatient IV antibiotics for Lyme disease only when clinical signs/symptoms are compatible and diagnosis is validated by serology and/or CSF testing per the CDC two-test approach (ELISA/IFA plus confirmatory Western blot), and when used for refractory Lyme arthritis after a failed 4-week oral course, specified moderate-to-severe cardiac involvement (e.g., PR >0.4 s, CHF, myopericarditis, ≥2nd-degree AV block), defined neurologic disease (encephalopathy/encephalomyelitis, CSF-confirmed meningitis with intrathecal antibody, radiculoneuropathy/peripheral neuropathy), or in pregnant women with stage II/III disseminated disease. IV antibiotic therapy is considered experimental/investigational and not medically necessary for early Lyme or new-onset Lyme arthritis, flu-like or nonspecific chronic symptoms (fatigue, cognitive issues, fibromyalgia, headache), prophylaxis in asymptomatic persons with only a positive test, or for mild cardiac findings (PR <0.4 s, LV dysfunction without CHF, transient ST‑T changes).