DAYS OF ERYTHROMYCIN ESTOLATE IS AS EFFECTIVE AS 14 DAYS FOR THE TREATMENT OF BORDETELLA-PERTUSSIS INFECTIONS

Objective and Methods. Although 14 days of erythromycin is recommended for the treatment of Bordetella pertussis infection, there have been no prospective controlled studies to support the contention that this long course of therapy is required to eradicate the microorganism from the nasopharynx or to prevent bacteriological relapse. We randomly al located children and adults with culture-positive community-acquired p ertussis to either 7 or 14 days of erythromycin estolate treatment (40 mg/kg/d; maximum dose 1 g/d). Nasopharyngeal aspirate cultures were o btained by study nurses during home visits before and at the end of tr eatment, and 1 week after the completion of treatment. B pertussis-spe cific antibodies were measured before treatment and 1 month later. Inf ormation about clinical symptoms, adverse reactions, and compliance we re collected at each scheduled contact. Results and Conclusions. A tot al of 168 participants were eligible for analysis (74 treated for 7 da ys and 94 treated for 19 days). Bacteriological persistence (positive end of therapy culture) occurred once in each group, and bacteriologic al relapse (positive culture 1 week after completion of treatment) occ urred in one participant treated for 7 days. The overall failure rate (persistence plus relapse) of 2.70% in the 7-day group was not differe nt than the rate of 1.06% in the 14-day group. The study had a power o f 99.99% at the 5% level to detect a difference in failure rates of 10 % and a power of 80% to detect a difference of 5%. We conclude that 7 days of erythromycin estolate is as effective as 14 days for the eradi cation of B pertussis.