Search

One-hundred thirteen men (mean age, 23 years) who presented with inguinal buboes to a government-operated hospital for sexually transmitted diseases (STDs) in Bangkok were studied between February 1987 and February 1989. The median duration of preceding symptoms was 7 days (range, 1-62 days). The majority of patients (74; 65%) had received treatment previously; 31 (27%) were febrile, 13 (12%) had extrainguinal lymphadenopathy, and 31 (27%) had concurrent active genital ulcers. There was no history of genital ulceration in 66 (58%) of the patients. Pus was obtained from 51 of the 110 buboes aspirated for culture; 21 (41%) of these cultures yielded Haemophilus ducreyi, and 2 (3.9%) were positive for Chlamydia trachomatis on immunofluorescence microscopy. Saline (1 mL) was injected and reaspirated from the buboes of 35 of the other 59 patients; 3 buboes yielded H. ducreyi and 9 were positive for C. trachomatis. All cultures for other aerobic and anaerobic bacteria and viruses in intact buboes were negative. Syphilis serology was positive in only one case. Patients attending STD clinics in this region who have large, fluctuant, edematous inguinal buboes containing pus should receive presumptive treatment for chancroid. If there is no pus, then the bubo is more likely to be caused by lymphogranuloma venereum.

We determined the in vitro susceptibilities of 54 isolates of Haemophilus ducreyi from Thailand (29 isolates) and San Francisco (25 isolates) to penicillin G, tetracycline, amoxicillin-clavulanic acid, ceftriaxone, cefixime, erythromycin, azithromycin, ciprofloxacin, ofloxacin, and trimethoprim-sulfamethoxazole. Isolates were susceptible to < or = 0.25 microgram of ceftriaxone per ml, < or less 0.5 microgram of cefixime per ml, < or = 0.125 microgram of ciprofloxacin per ml, and < or = 0.06 microgram of ofloxacin per ml. Erythromycin was active against all isolates (MIC for 90% of isolates tested, 0.25 microgram/ml), as was azithromycin (MIC, < or = micrograms/ml). In contrast, all but one isolate were resistant to > or = 8.0 micrograms of tetracycline per ml, 11.1% of the isolates were resistant to and 40.9% of the isolates were resistant to trimethoprim-sulfamethoxazole (MIC, > or = 4/76 microgram/ml.)

Thirty isolates of Haemophilus ducreyi collected in Thailand in 1984 were characterized by plasmid content. Three novel plasmids with estimated molecular masses of 1.8, 2.6, and 2.8 MDa were observed in 29 isolates, in addition to the 3.2-, 5.7-, and 7.0-MDa beta-lactamase and 4.4-MDa sulfonamide resistance plasmids. At least three of the seven plasmids were observed in each of the 29 isolates. The number and diversity of plasmids observed in these isolates of H. ducreyi distinguish them from strains previously described.

A single dose of ceftriaxone (250 mg) administered intramuscularly was compared with trimethoprim-sulfamethoxazole (TMP-SMZ; 160/800 mg) administered orally twice daily for seven days or with a single dose of TMP-SMZ (640/3,200 mg) administered orally for the treatment of chancroid in men in Thailand. Haemophilus ducreyi was isolated from 79 (48%) of 164 men with a clinical diagnosis of chancroid. For men with ulcers that were culture positive for H. ducreyi, rates of cure were 100% in 25 men treated with ceftriaxone, 87% in 23 men given TMP-SMZ for seven days, and 55% in 31 men given TMP-SMZ in a single dose. For men with ulcers that were culture negative for H. ducreyi, rates of cure were 100% in 29 men treated with ceftriaxone, 66% in 32 men given TMP-SMZ for seven days, and 63% in 24 men given TMP-SMZ in a single dose. The MIC50 of the three antibiotics for 94 isolates of H. ducreyi were as follows: 0.004 micrograms/ml for ceftriaxone, 16 micrograms/ml for trimethoprim, and greater than 512 micrograms/ml for sulfamethoxazole. Our study indicates that ceftriaxone in a single dose of 250 mg is effective, but that TMP-SMZ, even when given in a standard seven-day regimen, is not effective treatment for chancroid in Thailand.