Meningoencephalitis from Borrelia miyamotoi in an immunocompromised patient

N Engl J Med. 2013 Jan 17;368(3):240-5. doi: 10.1056/NEJMoa1209039.


Ixodes ticks serve as vectors for Borrelia burgdorferi, the agent of Lyme disease. Globally, these ticks often concurrently harbor B. miyamotoi, a spirochete that is classified within the relapsing-fever group of spirochetes. Although humans presumably are exposed to B. miyamotoi, there are limited data suggesting disease attributable to it. We report a case of progressive mental deterioration in an older, immunocompromised patient, and even though Koch's postulates were not met, we posit B. miyamotoi as the cause, owing to its direct detection in cerebrospinal fluid (CSF) with the use of microscopy and a polymerase-chain-reaction (PCR) assay. It is likely that B. miyamotoi is an underrecognized cause of disease, especially in sites where Lyme disease is endemic.

Publication types

  • Case Reports
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged, 80 and over
  • Borrelia / cytology
  • Borrelia / genetics
  • Borrelia / isolation & purification*
  • Borrelia Infections / complications
  • Borrelia Infections / diagnosis*
  • Borrelia Infections / immunology
  • Cerebrospinal Fluid / microbiology
  • Cognition Disorders / etiology
  • Female
  • Humans
  • Immunocompromised Host*
  • Meningoencephalitis / diagnosis*
  • Meningoencephalitis / microbiology
  • Phylogeny
  • Polymerase Chain Reaction