Chronic Q fever in the United States

J Clin Microbiol. 2006 Jun;44(6):2283-7. doi: 10.1128/JCM.02365-05.


Infections due to Coxiella burnetii, the causative agent of Q fever, are uncommon in the United States. Cases of chronic Q fever are extremely rare and most often manifest as culture-negative endocarditis in patients with underlying valvular heart disease. We describe a 31-year-old farmer from West Virginia with a history of congenital heart disease and recurrent fevers for 14 months who was diagnosed with Q fever endocarditis based on an extremely high antibody titer against Coxiella burnetii phase I antigen. Despite treatment with doxycycline, he continued to have markedly elevated Coxiella burnetii phase I antibody titers for 10 years after the initial diagnosis. To our knowledge, this case represents the longest follow-up period for a patient with chronic Q fever in the United States. We review all cases of chronic Q fever reported in the United States and discuss important issues pertaining to epidemiology, diagnosis, and management of this disease.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Adult
  • Antibodies, Bacterial / blood
  • Chronic Disease
  • Coxiella burnetii / immunology
  • Coxiella burnetii / isolation & purification*
  • Endocarditis, Bacterial / diagnosis
  • Endocarditis, Bacterial / epidemiology
  • Endocarditis, Bacterial / microbiology*
  • Humans
  • Male
  • Q Fever / diagnosis
  • Q Fever / epidemiology
  • Q Fever / microbiology*
  • United States / epidemiology


  • Antibodies, Bacterial