Bea Vuylsteke

Evidence of declining STD prevalence in a South African mining community following a core-group intervention.

Objectives: To reduce the prevalence of curable sexually transmitted diseases (STDs) in a South African mining community through provision of STD treatment services, including periodic presumptive treatment and prevention education to a core group of high‐risk women living in areas around the mines. Methods: Women at high risk for STDs attended a mobile clinic monthly for examination and counseling, and were treated presumptively for bacterial STDs with a directly observed 1‐g dose of azithromycin. Gonococcal and chlamydial infection rates were measured by urine ligase chain reaction, and genital ulcers were assessed by clinical examination. Changes in STD prevalence among local miners were assessed through comparison of prevalence in two cross‐sectional samples of miners taken 9 months apart, and through routine disease surveillance at mine health facilities. Results: During the first 9 months of the intervention, 407 women used the services. Baseline prevalence of Neisseria gonorrhoeae and/or Chlamydia trachomatis in women was 24.9%; 9.7% of these women had clinical evidence of genital ulcer disease (GUD). The proportion of women with incident gonococcal or chlamydial infections at the first monthly return visit (69% follow‐up rate) was 12.3%, and genital ulcers were found in 4.4% of these women. In the miner population, the prevalence of N gonorrhoeae and/or C trachomatis was 10.9% at baseline and 6.2% at the 9‐month follow‐up examination (P < 0.001). The prevalence of GUD by clinical examination was 5.8% at baseline and 1.3% at follow‐up examination (P < 0.001). Rates of symptomatic STDs seen at mine health facilities decreased among miners in the intervention area compared with miners living farther from the site and with less exposure to the project. Discussion: Provision of STD treatment services to a core group of high‐risk women may significantly reduce their burden of disease, and may contribute to a reduction in community STD prevalence. In the absence of sensitive and affordable screening tests for STDs in women, periodic presumptive treatment coupled with prevention education is a feasible approach to providing STD services in this population.

Cutting edge : Resistance to HIV-1 infection among african female sex workers is associated with inhibitory KIR in the absence of their HLA ligands

NK cells are regulated in part by killer Ig-like receptors (KIR) that interact with HLA molecules on potential target cells. KIR and HLA loci are highly polymorphic and certain KIR/HLA combinations were found to protect against HIV disease progression. We show in this study that KIR/HLA interactions also influence resistance to HIV transmission. HIV-exposed but seronegative female sex workers in Abidjan, Côte d’Ivoire, frequently possessed inhibitory KIR genes in the absence of their cognate HLA genes: KIR2DL2/KIR2DL3 heterozygosity in the absence of HLA-C1 and KIR3DL1 homozygosity in the absence of HLA-Bw4. HIV-seropositive female sex workers were characterized by corresponding inhibitory KIR/HLA pairings: KIR2DL3 homozygosity together with HLA-C1 and a trend toward KIR3DL1/HLA-Bw4 homozygosity. Absence of ligands for inhibitory KIR could lower the threshold for NK cell activation. In addition, exposed seronegatives more frequently possessed AB KIR genotypes, which contain more activating KIR. The data support an important role for NK cells and KIR/HLA interactions in antiviral immunity.

Comparison of culture and different PCR assays for detection of Trichomonas vaginalis in self collected vaginal swab specimens

Objectives: DNA amplification techniques have become widely used for the diagnosis of sexually transmitted infections. For the detection of Trichomonas vaginalis, PCR techniques are not yet widely used despite the publication of several assays. The sensitivity and specificity of five independent primer sets were determined on self collected vaginal specimens obtained from female commercial sex workers. Methods: Self collected specimens were obtained from symptomatic and asymptomatic women attending a female sex workers clinic in Abidjan, Côte d’Ivoire. Two vaginal specimens were collected, the first one was processed for culture and the second was processed for PCR analysis. PCR techniques for trichomonads were performed, using the primers as reported by Riley (TVA5/TVA6), Kengne (TVK3/TVK7), Madico (BTUB 9/BTUB 2), Shiao (IP1/IP2), and Mayta (TV1/TV2). An EIA amplicon detection method was designed for each of the primer sets. Results: True positive specimens were defined as culture positive and/or two positive PCR results with EIA amplicon detection in any combination. According to this definition a prevalence of 20% was obtained compared to 7% obtained by culture. The PCR primer set TVK3/TVK7 gave the highest sensitivity (89.2%). Poor sensitivities were obtained with the primer sets TV1/TV2 (60.2%) and TVA5/TVA6 (63.9%). PCR showed a sensitivity improvement of 2.4% up to 12% when EIA was used for amplicon detection. Conclusions: Overall, the sensitivities of the different PCR assays resulting from this study were lower than those previously described. These findings could be the result of the nature of the specimen population and suggests a strain variability.

Suppressed cellular alloimmune responses in HIV-exposed seronegative female sex workers

Particular human leucocyte antigen (HLA) polymorphisms have been associated with a reduced risk of HIV transmission. However, protective alloimmune responses expected to result from such a genetic predisposition have not been demonstrated. To this end, we analysed and compared cellular and humoral alloimmune responses in a cohort of female sex workers who remained human immunodeficiency virus (HIV)‐seronegative despite more than 3 years of high‐risk sexual activity (ESN FSWs) with those of low‐risk HIV‐seronegative female blood donors in Abidjan, Côte d’Ivoire. ESN FSWs showed significantly lower allostimulated CD69 expression and secretion of interferon‐γ, macrophage inflammatory protein (MIP)‐1β and RANTES (regulated upon activation, normal T‐cell expressed and secreted) by lymphocytes than controls. In contrast, ESN FSWs showed significantly higher mitogen‐stimulated CD69 expression and secretion of tumour necrosis factor‐α and MIP‐1β than controls. Suppression of cellular alloimmune responses among ESN FSWs was associated with a higher self‐reported frequency of unprotected sex. Levels of anti‐HLA class I alloantibodies in plasma were not significantly different between ESN FSWs and controls. These findings indicate that frequent sexual exposure to multiple partners results in suppression rather than activation of cellular alloimmune responses. Our data support the hypothesis that suppressed cellular alloimmune responses may play a role in protection against HIV infection.

Challenges in the conduct of vaginal microbicide effectiveness trials in the developing world.

Conducting a phase III trial of a vaginal microbicide in a developing country poses several important and complex ethical challenges. As part of a process to bridge the gap between ethical theory and practice, we share our experiences in performing a phase III trial of Col 1492 (Advantage S) among female sex workers at four sites world-wide; Durban, Abidjan, Cotonou and Hat Yai. The ethical challenges included: (i) difficulties in obtaining informed consent. Participants were unable to grasp the concepts of a clinical trial for several weeks to months. In Cotonou, 30% of the women did not know the gel was tested for HIV prevention. Only 25% understood what a placebo was. In Durban, 70% of the women did not fully understand the study after 3 months; (ii) in sustaining the use of known HIV prevention strategies. Participants at the Durban site had difficulty in sustaining condom use due to financial and client preferences. Sex without condoms was worth more (

Cellular Human Immunodeficiency Virus (HIV)–Protective Factors: A Comparison of HIV-Exposed Seronegative Female Sex Workers and Female Blood Donors in Abidjan, Côte d’Ivoire

20) than sex with condoms (

High prevalence of sexually transmitted diseases in a rural area in Mozambique.

10); (iii) in maintaining the confidentiality of the subjects HIV status. Novel approaches such as role plays and emphasis on other exclusion criteria were needed to maintain the confidentiality of women not included in the trial due to their HIV status; (iv) in providing care and support to the subjects who became infected with HIV during the trial. Women could only be offered routine sexually transmitted disease treatment and counselling. Anti-retrovirals were not offered. The successes and failures of the solutions attempted are described.

Low CD4+ T Cell Counts among African HIV-1 Infected Subjects with Group B KIR Haplotypes in the Absence of Specific Inhibitory KIR Ligands

Cellular factors that may protect against human immunodeficiency virus (HIV) infection were investigated in 27 HIV-exposed seronegative (ESN) female sex workers (FSWs) and 27 HIV-seronegative female blood donors. Compared with blood donors, ESN FSWs had significantly decreased expression levels of C-X-C chemokine receptor 4 (CXCR4), but not of C-C chemokine receptor 5, on both memory (P<.001) and naive (P=.041) CD4(+) T cells. CXCR4 down-regulation was associated with prolonged duration of commercial sex work by ESN FSWs. CD38 expression on CD8(+) T cells was significantly increased among ESN FSWs, compared with that among blood donors (P=.017). There were no differences in HLA-DR and CD62L expression between blood donors and ESN FSWs. Proportions of T cells producing the beta-chemokines RANTES (regulated on activation, normally T cell-expressed and -secreted), macrophage inflammatory protein (MIP)-1alpha, and MIP-1beta or the cytokines interleukin (IL)-2, IL-4, interferon-gamma, and tumor necrosis factor-alpha, were similar in the 2 groups. These data indicate that ESN FSWs differ from HIV-seronegative female blood donors with respect to immunological factors that have no clear protective potential against HIV transmission.

Community empowerment and involvement of female sex workers in targeted sexual and reproductive health interventions in Africa: a systematic review.

OBJECTIVE--To assess the extent of the sexually transmitted diseases (STDs) problem in a rural area of Mozambique. METHODS--A cross sectional study among pregnant women and patients presenting with genital complaints. Laboratory confirmation was done for gonorrhoea, chlamydial infection, active syphilis, trichomoniasis and HIV infection. SETTING--A primary health care setting in Vilanculos, Inhambane province, Mozambique. RESULTS--Evidence of one or more of the above STDs was found in 51% of 201 pregnant women, 56% of 85 women and 62% of 77 men with genital complaints. Neisseria gonorrhoea or Chlamydia trachomatis were found in 16% of pregnant women, 23% of female patients and 28% of male patients; genital ulcer disease was present in 6%, 28% and 36%, of respectively pregnant women, female and male patients. The prevalence of active syphilis was about the same in the three groups of study subjects, that is 15%. HIV infection was found in 4% of the male patients; no HIV infection could be detected in the female groups. CONCLUSION--STDs were a major health problem in this rural area in Mozambique. Though HIV infection was still low, the high prevalence of STDs indicates that the potential is there for an explosive spread of the HIV/AIDS epidemic.

The Epidemiology of HIV and Prevention Needs of Men Who Have Sex with Men in Abidjan, Cote d’Ivoire

Natural killer (NK) cells are regulated by interactions between polymorphic killer immunoglobulin-like receptors (KIR) and human leukocyte antigens (HLA). Genotypic combinations of KIR3DS1/L1 and HLA Bw4-80I were previously shown to influence HIV-1 disease progression, however other KIR genes have not been well studied. In this study, we analyzed the influence of all activating and inhibitory KIR, in association with the known HLA inhibitory KIR ligands, on markers of disease progression in a West African population of therapy-naïve HIV-1 infected subjects. We observed a significant association between carriage of a group B KIR haplotype and lower CD4+ T cell counts, with an additional effect for KIR3DS1 within the frame of this haplotype. In contrast, we found that individuals carrying genes for the inhibitory KIR ligands HLA-Bw4 as well as HLA-C1 showed significantly higher CD4+ T cell counts. These associations were independent from the viral load and from individual HIV-1 protective HLA alleles. Our data suggest that group B KIR haplotypes and lack of specific inhibitory KIR ligand genes, genotypes considered to favor NK cell activation, are predictive of HIV-1 disease progression.