TREATMENT OF LOUSE-BORNE RELAPSING FEVER WITH LOW-DOSE PENICILLIN OR TETRACYCLINE - A CLINICAL-TRIAL

A clinical trial was conducted in order to evaluate the efficacy of pr ocaine penicillin and tetracycline, respectively, in the treatment of louse-borne relapsing fever. 184 patients (160 men, 24 women) admitted to the Gondar hospital during the rainy season 1992 were assigned to 1 of 4 treatment groups: procaine penicillin 100,000 (PP100), 200,000 (PP200) or 400,000 (PP400) international units (IU) intramuscularly (i .m.), or tetracycline 250 mg per os (TTC, p.o.). All drugs were given as single doses. The overall case fatality rate was 3.3%. Frequency of relapses, Jarisch-Herxheimer-like reactions (JHR) and deaths were sig nificantly different between patients treated with TTC and those treat ed with PP100. Relapses occurred most often in the group receiving the lowest dose of penicillin (46%), and decreased with increasing dosage of penicillin; none of the patients treated with TTC had a relapse. O ccurrence of JHR showed the opposite pattern: whilst 2 (5%) patients t reated with PP100 developed a JHR, 16 (29%) in the PP200 group, 10 (31 %) in the PP400 group, and 27 (47%) in the TTC group developed a JHR. As mortality is linked to severe JHR, and most relapses are clinically mild and easily treated, these results speak in favour of using low-d ose penicillin to initiate the treatment of relapsing fever.