Isolation of Borrelia burgdorferi sensu lato from blood of patients with erythema migrans.

BACKGROUND

We assessed the isolation rate of Borrelia burgdorferi sensu lato from blood in European patients with typical erythema migrans and evaluated the course and outcome of their illness.

PATIENTS AND METHODS

Adult patients diagnosed with erythema migrans and from whom borreliae cultured from blood were included in this study.

RESULTS

Borreliae were isolated from the blood of 35/2,828 (1.2%) patients, on average 7 days (range 1-47 days) after the appearance of erythema migrans. Only seven (20%) patients reported constitutional symptoms. 24/35 isolates were typed of which 20 were Borrelia afzelii and four were Borrelia garinii. 31 (88.6%) patients were treated with oral antibiotics while four (11.4%) received ceftriaxone iv. The course and outcome of the illness were favorable in all patients.

CONCLUSION

In European patients with erythema migrans the yield of blood culturing was low, spirochetemia was often clinically silent and the course and outcome of the illness were favorable; the predominantly isolated strain was B. afzelii.