H Nsanze

Prostitutes are a major reservoir of sexually transmitted diseases in Nairobi, Kenya.

Prostitutes are a major reservoir of sexually transmitted diseases in many developing nations. In Nairobi we found that 16%, 28%, and 46%, respectively, of upper-, middle-, and lower-social strata prostitutes were infected with Neisseria gonorrhoeae. Genital ulcers and infections with Haemophilus ducreyi were more prevalent among prostitutes of the middle and lower social strata. A group of 97 prostitutes of the lower social strata were followed longitudinally to determine the rate of reinfection with N. gonorrhoeae. The mean time to acquisition of a new infection was 12.0 +/- 9.2 days. These results show that in Nairobi prostitutes are a readily identifiable group of high-frequency transmitters of gonococcal infection. Strategies based on intervention in the prostitute reservoir could prove to be an effective means of control of gonococcal infections in developing nations.

EPIDEMIOLOGY OF CHANCROID AND HAEMOPHILUS DUCREYI IN NAIROBI, KENYA

Of 300 men in Nairobi, Kenya, with culture-proven chancroid, 57% had acquired infection from prostitutes. The majority of infections were acquired in the city of Nairobi. All 10 female source contacts examined had genital ulcers. 13 of 29 female secondary contacts were culture-positive for Haemophilus ducreyi and 10 of these infected women had clinical chancroid. Of 122 prostitutes from the middle and lower social strata, 12 had genital ulcers, 5 of which were culture-positive for H ducreyi, and a further 5 had symptomless genital carriage of H ducreyi. Prostitutes are a major reservoir of H ducreyi in Nairobi. No evidence of transmission of H ducreyi by women without clinical chancroid was detected.

Single-Dose Therapy of Gonococcal Ophthalmia Neonatorum with Ceftriaxone

We conducted a randomized clinical trial comparing a single intramuscular dose of 125 mg of ceftriaxone with a single intramuscular dose of 75 mg of kanamycin followed by topical gentamicin for seven days, and with a single intramuscular dose of 75 mg of kanamycin followed by topical tetracycline for seven days, in the treatment of gonococcal ophthalmia neonatorum in Nairobi, Kenya. Of 122 newborns with culture-proved gonococcal ophthalmia neonatorum, 105 returned for follow-up. Sixty-one infants (54 percent) received ceftriaxone, 32 received kanamycin plus topical gentamicin, and 29 received kanamycin plus topical tetracycline. Sixty-six (54 percent) of the Neisseria gonorrhoeae isolates were penicillinase producing. All 55 newborns who received ceftriaxone and returned for follow-up were clinically and microbiologically cured. One of 26 returning newborns who received kanamycin plus tetracycline and 2 of 24 returning newborns who received kanamycin plus gentamicin had persistent or recurrent gonococcal conjunctivitis. Ceftriaxone also eradicated oropharyngeal gonococcal infection in 18 newborns, whereas oropharyngeal infection persisted in 2 of 8 newborns who had received kanamycin (P not significant). We conclude that 125 mg of ceftriaxone as a single intramuscular dose is very effective therapy for gonococcal ophthalmia neonatorum, with marked efficacy against extraocular infection and without the need for concomitant topical antimicrobial therapy.

Genital ulcers in Kenya. Clinical and laboratory study.

Of 97 patients with genital ulcers attending a special treatment clinic in Nairobi, Kenya, 60 harboured Haemophilus ducreyi, four herpes simplex virus, and five Neisseria gonorrhoeae. Eleven patients had serological evidence of syphilis; of these one case was confirmed by darkfield microscopy. In the remaining cases no aetiological agent was identified. An enriched chocolate agar with vancomycin and serum was a useful medium for primary isolation of H ducreyi. Tetracycline was generally ineffective in the treatment of ulcers, but sulfadimidine was successful in almost 80% of cases.

Comparison of media for the primary isolation of Haemophilus ducreyi

The rates of isolation of Haemophilus ducreyi from patients with presumed chancroid has been low, and improved cultural techniques are required. We determined the isloation rates of H. ducreyi from 38 patients with clinical chanceroid and compared gonococcal agar supplemented with bovine hemoglobin to Mueller-Hinton agar supplemented with chocolated horse blood, each with and without 5% fetal calf serum. The rate of isolation and the qualitative and quantitative growth of strains was best on gonococcal agar with added fetal calf serum (GC-HgS). However, three strains were isolated only on Mueller-Hinton base (MH-base). GC-HgS was compared with MH-HB for the isolation of H. ducreyi from 201 patients with clinical chancroid. Seventy-one percent of cultures were positive on GC-HgS, and 61% were positive on MH-HB (P < .005); however, 10% of cultures were positive only on MH-HB. The use of the two media together increased the yield of positive cultures to 81%. Thus maximal rates of isolation of H. ducreyi from clinical specimens requires the use of two media, GC-HgS and MH-HB.

Clinical and microbiologic studies of genital ulcers in Kenyan women.

The etiology of genital ulcers in women in tropical regions is poorly understood. Eighty-nine women, presenting to a sexually transmitted disease clinic in Nairobi (Kenya) with a primary complaint of genital ulcers, were evaluated prospectively in a clinical and laboratory study. A final etiologic diagnosis was possible for 60 (67%) of the women. Culture for Haemophilus ducreyi was positive for 43 women, eight had secondary syphilis with ulcerated condyloma latum, three had primary syphilis, one had both chancroid and syphilis, two had moniliasis, two had herpetic ulceration, and one had a traumatic ulcer. The clinical characteristics that best distinguished chancroid from secondary syphilis were ulcer excavation and a rough ulcer base. No etiologic diagnosis was established for 29 patients. However, the clinical and epidemiologic features of these patients suggested that they were similar if not identical to the patients with H. ducreyi culture-positive chancroid. Further studies are necessary to determine the etiology of ulcers in females in whom no pathogen was identified.

The clinical diagnosis of genital ulcer disease in men in the tropics

Since the clinical diagnosis of genital ulcers without laboratory confirmation is not reliable in developed countries, we postulated that clinical diagnosis alone would be no more reliable in developing countries. A presumptive clinical diagnosis of chancroid, genital herpes, syphilis, or lymphogranuloma venereum was made for 100 male patients at the Special Treatment Clinic in Nairobi, Kenya. This diagnosis was then compared to the final diagnosis determined by laboratory identification of the pathogen, by culture, or by serologic response. In 64 patients, a final diagnosis of either chancroid, syphilis, or genital herpes was established. The diagnostic accuracy varied from 75% for chancroid to 42% for syphilis and 43% for herpes. The overall diagnostic accuracy was 66%. The predictive values of positive clinical diagnoses were 84% for chancroid, 60% for syphilis, and 75% for herpes. Thus, clinical diagnosis of genital ulcer disease was not sufficiently reliable in this study.

TREATMENT OF CHANCROID BY CLAVULANIC ACID WITH AMOXYCILLIN IN PATIENTS WITH β-LACTAMASE-POSITIVE HAEMOPHILUS DUCREYI INFECTION

Multiresistant strains of Haemophilus ducreyi, the aetiological agent of chancroid, are prevalent in Nairobi, Kenya, where tetracyclines and sulphonamides are no longer very effective in the treatment of chancroid. The following regimens (given three times daily for seven days) were compared in a double-blind randomised trial--amoxycillin 500 mg, amoxycillin 500 mg and clavulanic acid 125 mg, and amoxycillin 500 mg and clavulanic acid 250 mg. 68 of 100 ulcers were culture-positive for H. ducreyi. All strains of H. ducreyi produced beta-lactamase. At day 7 none of the amoxycillin-treated patients had responded clinically or bacteriologically, whereas all but 2 of 56 patients treated with an amoxycillin/clavulanic-acid regimen had responded clinically and H. ducreyi had been eradicated from their ulcers. The combination of amoxycillin-clavulanic acid appears to be very effective for the treatment of chancroid. The results of this study accord with H. ducreyi as the primary pathogen of chancroid.

Single-dose ceftriaxone for chancroid.

Men with genital ulcers that were culture positive for Haemophilus 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.

Single-dose ceftriaxone therapy of gonococcal ophthalmia neonatorum

Ceftriaxone (125 mg) given as a single intramuscular dose without topical therapy was evaluated in seven infants with smear-positive gonococcal ophthalmia neonatorum. Neisseria gonorrhoeae was isolated from the eyes of six infants, and four of these isolates were penicillinase-producing N. gonorrhoeae. Two infants had concomitant ocular infection with Chlamydia trachomatis. All seven infants, when seen at follow-up, showed marked clinical improvement. Conjunctivitis resolved completely in four infants. One infant was lost to subsequent follow-up, while two infants had persistent ophthalmia due to C. trachomatis. Follow-up eye cultures for N. gonorrhoeae were all negative.