Single-dose ceftriaxone for chancroid

Abstract

Men with genital ulcers that were culture positive for Haemophiluss ducreyi were treated with intramuscular ceftriaxone and randomized to three different dose regimens. All but 1 of 50 men treated with 1 g of intramuscular ceftriaxone were cured. Similarly, 0.5 and 0.25 g cured 43 of 44 men and 37 of 38 men, respectively. A single dose of 250 mg of intramuscular ceftriaxone is an effective treatment for chancroid. Increasing awareness of antimicrobial agent-resistantHaemophilus ducreyi strains has led us' to search for alternate treatment regimens for chancroid (7). A 10-day course of erythromycin and a 1-week course of amoxicillin in combination with clavulanic acid are each satisfactory treatments, with cure rates of over 95% (2,10). More recently, we have shown that a single dose of trimethoprimsulfametrole (11) or of rifampin in combination with trimethoprim (12) can cure most patients with chancroid in Kenya. However, additional effective single-dose treatment regimens are necessary due to the recent emergence of trimethoprim-resistant H. ducreyi strains in Thailand (13).Ceftriaxone is remarkably effective -against H. ducreyi in vitro, with MICs of 0.015 mg/liter or'less for all isolates tested. In the present study, we compared three different single-dose intramuscular ceftriaxone regimens for the treatment of men with genital ulcer disease due to H. ducreyi. MATERIALS AND METHODSBetween April and December 1982, male patients presenting at the Nairobi Special Treatment Clinic with a clihical syndrome compatible with chancroid were enrolled in the study. Men were eligible if'they were older than 18 years, had had no antimicrobial therapy in the preceding week, were willing to return for follow-up, and were negative for Treponema pallidum on dark-field examination. The external genitalia were examined, and the number, size, and clinical characteristics of the ulcers were noted. Buboes, defined as tender inguinal or femoral lymph nodes enlarged to more than 1 cm, were examined for fluctuance, consistency, and size. Ulcers were cultured for H. ducreyi and herpes simplex virus by techniques described in an earlier publication (11). All ulcers were cultured on two different media, which in combination have been shown to support the growth of H. ducreyi from samples of ulcers from over 80% of patients with clinical chancroid (8). Agar dilution ceftriaxone and other cephalosporin MICs for H. ducreyi were determined as described previously (4). One or more dark-field examinations were performed on samples of all ulcers. Serum was obtained for serologic tests for syphilis initially and at 10 and 28 days.Patients who had positive cultures for H. ducreyi and no evidence of T. pallidum infection were assigned by a preconstructed random sequence to treatment with ceftriax-* Corresponding author.one in a dose of 1.0, 0.5, or 0.25 g. The ceftriaxone was administered intramuscularly after dilution in 1% xylocaine. The evaluator' was unaware of the treatment regimen selected.The men were requested to return for follow-up vi...

Chancroid and Haemophilus ducreyi

“…The genetics and mechanisms of the antibiotic resistance are discussed below. (21) France (144) 1978-1985 (155) Sulfamethoxazole >160 (>160) 64 (4.0->128) 64 The emergence of penicillin-resistant strains of H. ducreyi has necessitated the recognition of such strains. P-Lactamase has been detected by either a chromogenic cephalosporin (114) or an iodometric paper strip (74) test.…”

“…Thus, this model may be amenable to the study of the pathogenesis of chancroid and the virulence of H. ducreyi. SUSCEPTIBILITY TESTING Most of the published studies have used the agar dilution method (18,21,51,53,61,75,123,151,155,164,165) to determine the antimicrobial susceptibility of H. ducreyi. However, disk diffusion (27,53) and broth microdilution (84) techniques have also been used.…”

“…There is no standard medium for performing antimicrobial susceptibility tests on H. ducreyi. Enriched GC agar (21,61,123), enriched Mueller-Hinton agar (27,51,151,164), Beiling medium with Mueller-Hinton agar instead of Columbia agar (155), and Sheffield medium (75) have all been used. For this reason, it is often difficult to compare the MICs obtained in different studies.…”

Antimicrobial susceptibility of Haemophilus ducreyi

“…In Kenya, the sensitivity of isolation of H. ducreyi from presumptive chancroid lesions has increased to over 80%o when two such selective media are used (46). The introduction of these improved isolation techniques has also made it possible to correlate clinical and bacteriologic responses following therapy and to perform in vitro antimicrobial susceptibility tests (6,17,62 (29), all MIC determinations recorded to date have employed the agar dilution method (6,8,18,19,23,26,48,56,58,60,62 (13,19,23,41,50,56,60). The inoculum size ranged from 104 CFU (58) to 105 CFU (6,13,21,23,41,50,56,62), 106 CFU (7,18,22,63), and 107 CFU (66).…”

“…Initially, gonococcal agar base was preferred when sulfonamides were being tested (6,8,23,50), but more recently Mueller-Hinton agar base has been used (18,62). Both media are enriched with 0.1% glucose, 0.01% glutamine, 0.025% hemin, and 5% lysed horse blood.…”