Relapsing illness due to Rochalimaea henselae in immunocompetent hosts: implication for therapy and new epidemiological associations.

Two previously healthy, immunocompetent men had persistent Rochalimaea henselae bacteremia with clinical relapses after courses of antibiotics to which the isolates were ultimately demonstrated susceptible in vitro. Both had sustained tick bites prior to their illnesses, thus demonstrating an association not previously identified, although suspected. The first patient had relapsing fever, constitutional symptoms, and an episode of aseptic meningitis despite therapy with amoxicillin, then with doxycycline, and then with ceftriaxone. Thereafter, he spontaneously became asymptomatic during a span of 2 months of persistent bacteremia. Finally, after 2 weeks of therapy with ceftriaxone plus gentamicin, followed by 4 weeks of therapy with oral ciprofloxacin, his bacteremia was cured. The second man had relapsing fever and constitutional symptoms after courses of tetracycline, then of chloramphenicol, and then of doxycycline. He became permanently asymptomatic after serial 2-week courses of chloramphenicol and erythromycin. The greater efficacy of lysis-centrifugation blood cultures in the recovery of R. henselae was noted.