Treatment

Acute Q fever
  • Symptoms of acute Q fever usually resolve spontaneously within 2 weeks, but antibiotic treatment has been shown to reduce the duration of disease, especially if initiated within 3 days of illness onset. The optimal duration of treatment has not been adequately studied. Antibiotics are given for 14-21 days, usually in an outpatient setting.
  • Doxycycline has been the agent most frequently investigated It is currently the treatment of choice.
  • Fluoroquinolones can be used as alternatives. Ofloxacin and pefloxacin have been used with success in patients. Ciprofloxacin demonstrated higher MIC values than other fluoroquinolones and doxycycline. Levofloxacin showed bacteriostatic activity in vitro
  • Fluoroquinolones may offer a theoretical advantage in meningoencephalitis since they possess better cerebrospinal fluid penetration. A more recent literature review demonstrated that the choice of antimicrobial therapy (doxycycline vs fluoroquinolones) did not affect resolution of acute disease or severity of neurologic sequelae
  • Macrolides, especially azithromycin and clarithromycin, can be used as alternatives, but some strains of C burnetii show resistance/
  • Trimethoprim-sulfamethoxazole (TMP-SMX) has also been used.
  • No reliable regimen is available for children (< 8 y) or pregnant women. Macrolides or TMP-SMX may be options in these populations
  • Adjuvant corticosteroid treatment has been used in antimicrobial-nonresponsive hepatitis.
Chronic Q fever
  • Chronic C burnetii infections are very difficult to treat. A prolonged combined antimicrobial regimen is recommended. Hospitalization may be warranted for intractable heart failure.
  • No drug used alone has been shown to be bactericidal against C burnetii. Therefore, prolonged combination therapy is recommended because of the high rate of relapse with treatment of shorter duration. No consensus on the ideal duration of therapy has been reached, but serial measurement of antibody titers should likely be used as a guide to duration of therapy.
  • The most current recommendation for endocarditis is combination treatment with doxycycline and hydroxychloroquine for at least 18 months. An alternative option is combination of doxycycline and a fluoroquinolone for at least 3-4 years. Other proposed alternatives include doxycycline or fluoroquinolones with rifampin therapy, although significant drug interactions could limit these regimens.
  • The use of hydroxychloroquine is based on the assumption that it will elevate the pH within the phagolysosome vacuole of the monocyte, where C burnetii resides. This might affect the metabolism of the organism, rendering it more susceptible to the effects of doxycycline.
  • Endovascular complications should also be treated with doxycycline and hydroxychloroquine in combination, although the optimal regimen is not well defined.
  • Osteoarticular infections should also be treated with prolonged antimicrobial combination therapy, along with surgical debridement. A regimen of doxycycline and hydroxychloroquine, with or without rifampin, has been suggested