Effect of interventions to control sexually transmitted disease on the incidence of HIV infection in female sex workers.

OBJECTIVE: To compare the seroincidence of HIV infection among female sex workers in Abidjan, Côte d'Ivoire before and during an intervention study to control sexually transmitted diseases (STD) and to study the effect of two STD diagnosis and treatment strategies on the prevalence of STD and on the seroincidence of HIV infection. METHOD: A screening facility for STD and HIV had been available since October 1992 for female sex workers. From June 1994, women who were HIV seronegative or HIV-2 positive during the screening could enroll in the intervention study in which participants reported once a month to a confidential clinic where they received health education, condoms and STD treatment if indicated. Women in the study were randomized either to a basic STD diagnosis and treatment strategy, which included a gynecologic examination when symptomatic, or to an intensive strategy that included a gynecologic examination regardless of symptoms. An outcome assessment every 6 months included a gynecologic examination, HIV serology and laboratory tests for STD. RESULTS: Of 542 women enrolled in the study, 225 (42%) had at least one outcome assessment. The HIV-1 seroincidence rate during the intervention study was significantly lower than before the study (6.5 versus 16.3 per 100 person-years; P = 0.02). During the study, the HIV-1 seroincidence rate was slightly lower in the intensive than in the basic strategy (5.3 versus 7.6 per 100 person-years; P = 0.5). CONCLUSION: National AIDS control programs should consider adopting as policy the type of integrated approach used in this intervention study for HIV prevention in female sex workers.

Evaluation of simple diagnostic algorithms for Neisseria gonorrhoeae and Chlamydia trachomatis cervical infections in female sex workers in Abidjan, Côte d'Ivoire.

OBJECTIVE: To generate simple algorithms for the diagnosis of cervical infection with Neisseria gonorrhoeae or Chlamydia trachomatis in female sex workers in Abidjan, Côte d'Ivoire and to evaluate their validity. METHODS: From October 1992 to the end of June 1993, female sex workers were interviewed and clinically examined at a confidential clinic. N gonorrhoeae was cultured on modified Thayer-Martin medium and C trachomatis was detected by polymerase chain reaction. The associations of gonococcal or chlamydial cervical infection with sociodemographic, behavioural, clinical, and biological factors were assessed and three algorithms were generated. The validity parameters of these diagnostic algorithms were calculated and compared to those of standard algorithms and mass treatment. RESULTS: Among 683 women, cervical infection was present in 239 (35%). The sensitivity an algorithm incorporating sociodemographic and behavioural factors and symptoms, of an algorithm incorporating clinical signs and simple laboratory tests, and of a combined algorithm was 83%, 86%, and 79% respectively while the specificity was 32%, 44%, and 54%, and the positive predictive value 40%, 46%, and 48% respectively. A standard algorithm incorporating only the symptom vaginal discharge, and a standard algorithm requiring both the symptom vaginal discharge and the presence of an endocervical mucopurulent discharge on examination had a sensitivity of 44% and 18%, a specificity of 75% and 95%, and a positive predictive value of 49% and 67% respectively. CONCLUSIONS: The algorithms generated in this study may be useful for the control of cervical infections in female sex workers in resource poor settings in the absence of rapid, inexpensive, and accurate laboratory tests for the diagnosis of cervical infections.

Excluding blood donors at high risk of HIV infection in a west African city.

OBJECTIVE: To examine the potential impact of deferral of blood donors at high risk of HIV infection in a west African city where blood is screened for HIV antibodies but no other special measures are taken to protect the blood supply. DESIGN: Cross sectional study. SETTING: National Blood Transfusion Centre and Project RETRO-CI, an international collaborative AIDS research project, Abidjan, Côte d'Ivoire. SUBJECTS: 1257 male first time blood donors. INTERVENTIONS: Blood donors were interviewed about demographic and behavioural characteristics and tested for HIV antibodies by enzyme immunoassay and, if positive, synthetic peptide based tests. MAIN OUTCOME MEASURES: HIV antibody status in relation to presence of behavioural risk factors; calculation of sensitivity, specificity, and predictive values of specific criteria for excluding HIV infected donors. RESULTS: The overall prevalence of HIV infection was 11.4%. The most important risk factors for HIV positivity were prostitute contact and being aged 30-39 years. For identifying seropositive donors individual criteria had sensitivity, specificity, and positive predictive values ranging from 15% to 98%, 38% to 91%, and 17% to 30% respectively. Prostitute contact in the past five years would have excluded 31% of all donors and 73% of HIV infected donors. 27% of those excluded would have been HIV positive. CONCLUSIONS: The widespread assumption that donor deferral is not feasible in sub-Saharan Africa needs reassessment. In Abidjan this approach was well accepted and potentially effective. Donor deferral requires evaluation as a strategy for improving blood safety in resource poor areas with high rates of HIV infection.

PIP: During February-November 1991 in Abidjan, the Ivory Coast, interviews with 1257 male first-time blood donors and screening of their blood for antibodies to HIV-1 and HIV-2 were conducted at the National Blood Transfusion Center to determine whether it is feasible to exclude or defer donors at high risk of HIV infection. 143 (11.4%) men had antibodies to HIV. The multivariate analysis showed that the strongest risk factor for HIV infection was sex with prostitutes in the last 5 years without regular condom use (odds ratio [OR] = 10, confidence interval [CI] = 6.6-15) followed by prostitute contact in the last 5 years regardless of condom use (OR = 8.4, CI = 5.6-12.6), and an age of 30-39 years (OR = 6.9, CI = 18). 27% of all donors with prostitute contact in the last 5 years were infected (positive predictive value). If the center had used prostitute contact in the last 5 years as a criterion, it would have discarded 31% of all units of blood. Thus, more than 75% of all potentially excluded units would have been from donors infected with HIV. The sensitivity, specificity, and positive predictive values ranged from 15% to 98%, 38% to 91%, and 17% to 30%, respectively. These findings suggest that it is feasible in Abidjan to exclude donors based on behavioral characteristics of those most at risk of HIV infection. Donor deferral should be evaluated as a strategy to improve blood safety in resource-poor areas with high rates of HIV infection.