Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 34-12: Borrelia miyamotoi Disease + Key Features Download Section PDF Listen +++ ++ An emerging spirochetal disease caused by B miyamotoi subspecies, which are taxonomically closely related to Borrelia recurrentis and Borrelia hermsii, the pathogens of relapsing fever Similarities between BMD and Lyme disease Both transmitted by Ixodes ticks Commonly found in same regions Differences between BMD and Lyme disease BMD: Peak months of risk to humans is later in summer to early fall because B miyamotoi can be vertically transmitted to larval Ixodes ticks Lyme disease: Peak months of risk to humans is early summer because Borrelia burgdorferi is transmitted by the nymph or adult tick Prevalence of B miyamotoi in the northern United States is 5% or less, compared to up to 30% for B burgdorferi An additional contrast is that BMD may occur shortly after attachment of an infected tick, while Lyme disease risk is highest after 36–48 hours of attachment and feeding on a human host Rodents and birds are reservoirs for B miyamotoi Avoidance of tick exposure is best prevention + Clinical Findings Download Section PDF Listen +++ ++ Fever occurs in almost all cases Fatigue, myalgia, chills, and nausea Meningoencephalitis, headache or cognitive impairment can predominate in more severe disease or in elderly patients Rashes are uncommon (< 10% of cases) Differential diagnosis Lyme disease without rash Human granulocytic anaplasmosis Babesiosis Ehrlichiosis + Diagnosis Download Section PDF Listen +++ ++ Leukopenia Thrombocytopenia Elevated liver biochemical tests Polymerase chain reaction (PCR) of blood or cerebrospinal fluid (CSF) samples When drawn during acute disease, may be helpful to detect B miyamotoi Negative results do not necessarily rule out BMD If PCR is not available, spirochetes may sometimes be visualized on a blood smear using Wright or Giemsa-stain or by darkfield microscopy of CSF If using the recommended two step testing algorithm for B burgdorferi (enzyme immunoassay [EIA] followed by immunoblot), the EIA may be positive in BMD due to cross-reactivity but the confirmatory immunoblot will be negative Glp-Q protein-based assay can distinguish between B burgdorferi and B miyamotoi However, these tests may also be positive for the Borrelia of relapsing fever Paired acute and convalescent sera may be most useful for confirming the diagnosis in hindsight + Treatment Download Section PDF Listen +++ ++ Doxycycline 100 mg orally twice daily for 14 days Ceftriaxone 2 g intravenously once daily for 2–4 weeks may be given for severe or CNS disease