title: Xenodiagnosis to detect Borrelia burgdorferi infection: a first-in-human study.
abstract: BACKGROUND
  Animal studies suggest that Borrelia burgdorferi, the agent of Lyme disease, may persist after antibiotic therapy and can be detected by various means including xenodiagnosis using the natural tick vector (Ixodes scapularis). No convincing evidence exists for the persistence of viable spirochetes after recommended courses of antibiotic therapy in humans. We determined the safety of using I. scapularis larvae for the xenodiagnosis of B. burgdorferi infection in humans.
  
  
  METHODS
  Laboratory-reared larval I. scapularis ticks were placed on 36 subjects and allowed to feed to repletion. Ticks were tested for B. burgdorferi by polymerase chain reaction (PCR), culture, and/or isothermal amplification followed by PCR and electrospray ionization mass spectroscopy. In addition, attempts were made to infect immunodeficient mice by tick bite or inoculation of tick contents. Xenodiagnosis was repeated in 7 individuals.
  
  
  RESULTS
  Xenodiagnosis was well tolerated with no severe adverse events. The most common adverse event was mild itching at the tick attachment site. Xenodiagnosis was negative in 16 patients with posttreatment Lyme disease syndrome (PTLDS) and/or high C6 antibody levels and in 5 patients after completing antibiotic therapy for erythema migrans. Xenodiagnosis was positive for B. burgdorferi DNA in a patient with erythema migrans early during therapy and in a patient with PTLDS. There is insufficient evidence, however, to conclude that viable spirochetes were present in either patient.
  
  
  CONCLUSIONS
  Xenodiagnosis using Ixodes scapularis larvae was safe and well tolerated. Further studies are needed to determine the sensitivity of xenodiagnosis in patients with Lyme disease and the significance of a positive result. Clinical Trials Registration NCT01143558.
authors: Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland.
authors: Adriana
authors: A
authors: Marques
authors: Sam R
authors: SR
authors: Telford
authors: Siu-Ping
authors: SP
authors: Turk
authors: Erin
authors: E
authors: Chung
authors: Carla
authors: C
authors: Williams
authors: Kenneth
authors: K
authors: Dardick
authors: Peter J
authors: PJ
authors: Krause
authors: Christina
authors: C
authors: Brandeburg
authors: Christopher D
authors: CD
authors: Crowder
authors: Heather E
authors: HE
authors: Carolan
authors: Mark W
authors: MW
authors: Eshoo
authors: Pamela A
authors: PA
authors: Shaw
authors: Linden T
authors: LT
authors: Hu
mesh_terms: D000818:Animals; D001096:Arachnid Vectors / Q000382:microbiology*; D025065:Borrelia burgdorferi / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D005929:Glossitis, Benign Migratory / Q000382:microbiology; D006801:Humans; D018884:Ixodes / Q000382:microbiology*; D008193:Lyme Disease / Q000175:diagnosis* / Q000635:transmission; D008297:Male; D051379:Mice; D016513:Mice, SCID; D008875:Middle Aged; D020525:Xenodiagnosis / Q000379:methods*
keywords: Borrelia burgdorferi; Ixodes scapularis; Lyme disease; human; xenodiagnosis