Comparison of antibiotic regimens for treating louse-borne relapsing fever: a meta-analysis

The optimum treatment for louse-borne relapsing fever (LBRF) has not been fully established. Eliminating spirochetes is often associated with the potentially lethal Jarisch-Herxheimer reaction (JHR). The objective of this meta-analysis was to review the evidence supporting the use of antibiotics usually employed for treating LBRF. A systematic review of the literature was performed to identify randomised controlled trials (RCT) comparing antibiotics in LBRF. The primary outcome was mortality, whilst JHR rates, relapse rates, time to fever clearance and time to spirochete disappearance were secondary outcomes. Six RCTs performed in Ethiopia were included. Trials were small and often of limited quality, using single-dose therapy with either penicillin or tetracycline. There was no significant difference between tetracycline and penicillin with regard to mortality rate. Although there was significant heterogeneity between the five trials comparing the rate of JHRs, three of them showed a significant benefit in favour of penicillin. The risk of relapse was reduced with tetracycline. Tetracycline use was associated with a lower mean fever clearance time. Tetracycline appears to be the most efficient drug but also appears to be associated with a higher rate of JHRs. Alternative regimens to treat LBRF should be investigated.