Treatment of chancroid with a single dose of spectinomycin

Fifty patients with lesions characteristic of chancroid were enrolled in an open-label prospective study to examine the efficacy of a single 2-gm dose of spectinomycin for treatment of chancroid. Only those patients (41 men; aged 18 to 49 years) with positive culture results for Haemophilus ducreyi were included in the analysis. Patients each received a single 2-gm dose of spectinomycin intramuscularly. The recovery process began on the third day of follow-up, as evidenced by the occurrence of epithelialization and a decrease in inflammation. By the seventh day after treatment, only one patient had ulcers; 40 patients experienced eradication of all ulcers (P less than 0.0001). The condition of nodes affected by infection also indicated efficacy of treatment (P less than 0.01); only one patient still had a swollen node by the fourteenth day after treatment. Of the 41 patients, 37 (90%) had negative culture results for H. ducreyi on the third day after treatment. Only 4 patients (10%) required a second dose of spectinomycin on the seventh day to affect a cure. Treatment with spectinomycin resulted in a 98% cure rate 14 days after treatment. The minimum inhibitory concentration (MIC) of spectinomycin was 1 microgram/mL to 3 micrograms/mL in the 15 strains studied. The drug was well tolerated and no adverse reactions were reported. It is concluded that a single 2-gm dose of spectinomycin is a safe and effective alternative drug for treatment of chancroid.