Ronald Ar

Female to male transmission of human immunodeficiency virus type 1: risk factors for seroconversion in men

To determine the frequency and risk factors for female to male sexual transmission of human immunodeficiency virus type 1 (HIV-1), a prospective study was carried out in 422 men who had acquired a sexually transmitted disease (STD) from a group of prostitutes with a prevalence of HIV-1 infection of 85%. The initial seroprevalence of HIV among the men was 12%. 24 of 293 (8.2%) initially seronegative men seroconverted to HIV-1. Newly acquired infection was independently associated with frequent prostitute contact (risk ratio 3.2, 95% confidence interval 1.2-8.1), with the acquisition of genital ulcer disease (risk ratio 4.7, 95% confidence interval 1.3-17.0), and with being uncircumcised (risk ratio 8.2, 95% confidence interval 3.0-23.0). 96% of documented seroconversions occurred in men with one or both of the latter two risk factors. In a subgroup of 73 seronegative men who reported a single prostitute sexual contact, the frequency of HIV-1 infection was 8.2% during 12 weeks of observation. No man without a genital ulcer seroconverted. A cumulative 43% of uncircumcised men who acquired an ulcer seroconverted to HIV-1 after a single sexual exposure. These data indicate an extremely high rate of female to male transmission of HIV-1 in the presence of STD and confirm a causal relation between lack of male circumcision, genital ulcer disease, and susceptibility to HIV-1 infection.

Human immunodeficiency virus infection among men with sexually transmitted diseases. Experience from a center in Africa

Heterosexual transmission of the human immunodeficiency virus (HIV) appears to occur readily in Africa but less commonly in North America and Europe. We conducted a case-control study among men attending a clinic for sexually transmitted diseases in Nairobi to determine the prevalence of HIV infection and the risk factors involved. HIV antibody was detected in 11.2 percent of 340 men who enrolled in the study. Reports of nonvaginal heterosexual intercourse and homosexuality were notably rare. Recent injections and blood transfusions were not associated with HIV infection. Travel and frequent contact with prostitutes were associated with HIV seropositivity. Men who were uncircumcised were more likely to have HIV infection (odds ratio, 2.7; P = 0.003), as were those who reported a history of genital ulcers (odds ratio, 7.2; P less than 0.001). A current diagnosis of genital ulcers was also associated with HIV seropositivity (odds ratio, 2.0; P = 0.028). Multivariate analysis revealed an independent association of genital ulcers with HIV infection in both circumcised and uncircumcised men. Uncircumcised men were more frequently infected with HIV, regardless of a history of genital ulcers. Our study finds that genital ulcers and an intact foreskin are associated with HIV infection in men with a sexually transmitted disease. Genital ulcers may increase mens susceptibility to HIV, or they may increase the infectivity of women infected with HIV. The intact foreskin may operate to increase the susceptibility to HIV.

PREVENTION OF TRANSMISSION OF HUMAN IMMUNODEFICIENCY VIRUS IN AFRICA: EFFECTIVENESS OF CONDOM PROMOTION AND HEALTH EDUCATION AMONG PROSTITUTES

Condom use was assessed after a programme of education about the acquired immunodeficiency syndrome and a condom distribution programme in a well-characterised prostitute population in Nairobi. Women received their education at group meetings (barazas) and at individual counselling sessions during which they were given the results of serological tests for the human immunodeficiency virus (group 1) or at barazas only (group 2), or through very little of either (group 3). During the counselling sessions free condoms were distributed. Before either of the programmes started, 10%, 9%, and 7% of groups 1, 2, and 3 women, respectively, reported occasional use of condoms. By November 1986, 80%, 70%, and 58% of groups 1, 2, and 3 women, respectively, reported at least some condom use. The mean frequency of condom use was 38.7 (SD 31.8)%, 34.6 (34.5)%, and 25.6 (29.5)% of sexual encounters in groups 1, 2, and 3 women. 20 of 28 women who were non-condom-users seroconverted compared with 23 of 50 women who reported some use of condoms.

The interaction of HIV infection and other sexually transmitted diseases: an opportunity for intervention.

In the US and Europe heterosexual intercourse appears to be an inefficient way of transmitting HIV whereas in Central Africa it is the predominant mode of transmission. The reason may lie in the fact that standard sexually-transmitted diseases which are prevalent in Africa South of the Sahara act as cofactors in HIV transmission by increasing the number of activated T4 lymphocytes. In developing countries a past history of sexually-transmitted diseases has been found in most AIDS patients -- 50% in Kinshasa 35% in Tanzania 67% in Rwanda 71% in Haiti 70% in Martinique 75% in males in Zimbabwe and 51% in females. Prostitutes are an important reservoir of sexually-transmitted diseases in Africa and HIV seropositivity among prostitutes is increasing rapidly -- 68% in Uganda and 85% in Nairobi. In both the US and Africa there is a high correlation between HIV seropositivity and a past history of syphilis especially among men. Both prospective and retrospective studies have shown an association between past history of genital ulcer disease (mainly chancroid) and HIV seropositivity. In Nairobi among 115 heterosexuals presenting with genital ulcer disease 63% of the HIV seropositives reported a prior episode of genital ulcer disease. Among 123 HIV seronegative prostitutes seroconversion to HIV-positive was significantly associated with occurrence of genital ulcer disease. A study in San Francisco showed that 68% of HIV-seronegative homosexuals became seropositive at the same time as they developed antibodies to herpes simplex type 2. There is also some evidence associating HIV seropositivity with Chlamydia trachomatis and gonorrhea. 5 US cases have been reported of rapid progression of syphilis to tertiary stage in HIV-seropositive patients. The strongest evidence indicates that genital ulcer disease (chancroid syphilis herpes) facilitates the sexual transmission of HIV. Early detection and drug therapy of bacterial sexually-transmitted diseases should be given high priority in primary health care facilities as 1 way of stemming the spread of HIV.

EPIDEMIOLOGY OF OPHTHALMIA NEONATORUM IN KENYA

In a Nairobi hospital where ocular prophylaxis against ophthalmia neonatorum has been discontinued, 1,019 women were screened for Neisseria gonorrhoeae and Chlamydia trachomatis during labour and 7 and 28 days postpartum. The prevalence of gonococcal infection was 7% and that of chlamydial was 29%. 52.4% of gonococcal isolates produced penicillinase. The incidence of ophthalmia neonatorum was 23.2 per 100 live births, and incidences of gonococcal and chlamydial ophthalmia were 3.6 and 8.1 per 100 live births, respectively. Of 181 cases of neonatal conjunctivitis, 31% were caused by C trachomatis, 12% by N gonorrhoeae, and 3% by both. In 67 babies exposed to maternal gonococcal infection and 201 exposed to maternal chlamydial infection, rates of transmission to the eye were 42% and 31%, respectively, and to the throat were 7% and 2%. Gonococcal transmission rate was higher in mothers with concomitant chlamydial infection (68%; p = 0.01). Postpartum endometritis was associated with ophthalmia neonatorum (p less than 0.001). Ocular prophylaxis at birth for gonococcal ophthalmia should be reintroduced.

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.

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.

Evaluation of fleroxacin (RO 23-6240) as single-oral-dose therapy of culture-proven chancroid in Nairobi, Kenya.

Chancroid is gaining importance as a sexually transmitted disease because of its association with transmission of human immunodeficiency virus type 1 (HIV-1). Effective, simply administered therapy for chancroid is necessary. Fleroxacin is effective against Haemophilus ducreyi in vitro. We performed an initial randomized clinical trial to assess the efficacy of fleroxacin for treatment of chancroid in Nairobi, Kenya. Fifty-three men with culture-positive chancroid were randomly assigned to receive either 200 mg (group 1) or 400 mg (group 2) of fleroxacin as a single oral dose. Groups 1 and 2 were similar with regard to severity of disease, bubo formation, and HIV-1 status. A satisfactory clinical response to therapy was noted in 23 of 26 patients (88%) in group 1 and 18 of 23 patients (78%) in group 2. Bacteriological failure occurred in 1 of 26 evaluable patients (4%) in group 1 and 4 of 23 evaluable patients (17%) in group 2. Two of 37 HIV-1-seronegative men (5%) and 3 of 11 HIV-1-infected men (27%) were bacteriological failures. Fleroxacin, 200 or 400 mg as a single oral dose, is efficacious therapy for microbiologically proven chancroid in patients who do not have concurrent HIV-1 infection. Among HIV-1-infected men, a single dose of 200 or 400 mg of fleroxacin is inadequate therapy for chancroid.

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.