Cheryl Baxter

Effectiveness and Safety of Tenofovir Gel, an Antiretroviral Microbicide, for the Prevention of HIV Infection in Women

Vaginal Gel Versus HIV HIV prevention technologies for women are urgently needed, especially in sub-Saharan Africa where young women bear the greatest burden of the HIV epidemic. Abdool Karim et al. (p. 1168; published online 19 July) present the results of the CAPRISA 004 randomized control trial. The nearly 3-year-long trial, conducted in urban and rural South African women, tested the efficacy of a vaginal gel containing the antiretroviral drug tenofovir in preventing HIV infection. The dosing strategy required application of the gel both before and after coitus, and with this regime HIV infection was reduced by approximately 39% overall, by 54% in women with high adherence to the protocol, and with no increase in overall adverse event rates. Tenofovir in a vaginal gel formulation shows significant protection against HIV infection in a randomized control trial. The Centre for the AIDS Program of Research in South Africa (CAPRISA) 004 trial assessed the effectiveness and safety of a 1% vaginal gel formulation of tenofovir, a nucleotide reverse transcriptase inhibitor, for the prevention of HIV acquisition in women. A double-blind, randomized controlled trial was conducted comparing tenofovir gel (n = 445 women) with placebo gel (n = 444 women) in sexually active, HIV-uninfected 18- to 40-year-old women in urban and rural KwaZulu-Natal, South Africa. HIV serostatus, safety, sexual behavior, and gel and condom use were assessed at monthly follow-up visits for 30 months. HIV incidence in the tenofovir gel arm was 5.6 per 100 women-years (person time of study observation) (38 out of 680.6 women-years) compared with 9.1 per 100 women-years (60 out of 660.7 women-years) in the placebo gel arm (incidence rate ratio = 0.61; P = 0.017). In high adherers (gel adherence > 80%), HIV incidence was 54% lower (P = 0.025) in the tenofovir gel arm. In intermediate adherers (gel adherence 50 to 80%) and low adherers (gel adherence < 50%), the HIV incidence reduction was 38 and 28%, respectively. Tenofovir gel reduced HIV acquisition by an estimated 39% overall, and by 54% in women with high gel adherence. No increase in the overall adverse event rates was observed. There were no changes in viral load and no tenofovir resistance in HIV seroconverters. Tenofovir gel could potentially fill an important HIV prevention gap, especially for women unable to successfully negotiate mutual monogamy or condom use.

Timing of Initiation of Antiretroviral Drugs during Tuberculosis Therapy

BACKGROUND The rates of death are high among patients with coinfection with tuberculosis and the human immunodeficiency virus (HIV). The optimal timing for the initiation of antiretroviral therapy in relation to tuberculosis therapy remains controversial. METHODS In an open-label, randomized, controlled trial in Durban, South Africa, we assigned 642 patients with both tuberculosis and HIV infection to start antiretroviral therapy either during tuberculosis therapy (in two integrated-therapy groups) or after the completion of such treatment (in one sequential-therapy group). The diagnosis of tuberculosis was based on a positive sputum smear for acid-fast bacilli. Only patients with HIV infection and a CD4+ cell count of less than 500 per cubic millimeter were included. All patients received standard tuberculosis therapy, prophylaxis with trimethoprim-sulfamethoxazole, and a once-daily antiretroviral regimen of didanosine, lamivudine, and efavirenz. The primary end point was death from any cause. RESULTS This analysis compares data from the sequential-therapy group and the combined integrated-therapy groups up to September 1, 2008, when the data and safety monitoring committee recommended that all patients receive integrated antiretroviral therapy. There was a reduction in the rate of death among the 429 patients in the combined integrated-therapy groups (5.4 deaths per 100 person-years, or 25 deaths), as compared with the 213 patients in the sequential-therapy group (12.1 per 100 person-years, or 27 deaths); a relative reduction of 56% (hazard ratio in the combined integrated-therapy groups, 0.44; 95% confidence interval, 0.25 to 0.79; P=0.003). Mortality was lower in the combined integrated-therapy groups in all CD4+ count strata. Rates of adverse events during follow-up were similar in the two study groups. CONCLUSIONS The initiation of antiretroviral therapy during tuberculosis therapy significantly improved survival and provides further impetus for the integration of tuberculosis and HIV services. (ClinicalTrials.gov number, NCT00398996.)

Integration of antiretroviral therapy with tuberculosis treatment.

BACKGROUND We previously reported that integrating antiretroviral therapy (ART) with tuberculosis treatment reduces mortality. However, the timing for the initiation of ART during tuberculosis treatment remains unresolved. METHODS We conducted a three-group, open-label, randomized, controlled trial in South Africa involving 642 ambulatory patients, all with tuberculosis (confirmed by a positive sputum smear for acid-fast bacilli), human immunodeficiency virus infection, and a CD4+ T-cell count of less than 500 per cubic millimeter. Findings in the earlier-ART group (ART initiated within 4 weeks after the start of tuberculosis treatment, 214 patients) and later-ART group (ART initiated during the first 4 weeks of the continuation phase of tuberculosis treatment, 215 patients) are presented here. RESULTS At baseline, the median CD4+ T-cell count was 150 per cubic millimeter, and the median viral load was 161,000 copies per milliliter, with no significant differences between the two groups. The incidence rate of the acquired immunodeficiency syndrome (AIDS) or death was 6.9 cases per 100 person-years in the earlier-ART group (18 cases) as compared with 7.8 per 100 person-years in the later-ART group (19 cases) (incidence-rate ratio, 0.89; 95% confidence interval [CI], 0.44 to 1.79; P=0.73). However, among patients with CD4+ T-cell counts of less than 50 per cubic millimeter, the incidence rates of AIDS or death were 8.5 and 26.3 cases per 100 person-years, respectively (incidence-rate ratio, 0.32; 95% CI, 0.07 to 1.13; P=0.06). The incidence rates of the immune reconstitution inflammatory syndrome (IRIS) were 20.1 and 7.7 cases per 100 person-years, respectively (incidence-rate ratio, 2.62; 95% CI, 1.48 to 4.82; P<0.001). Adverse events requiring a switching of antiretroviral drugs occurred in 10 patients in the earlier-ART group and 1 patient in the later-ART group (P=0.006). CONCLUSIONS Early initiation of ART in patients with CD4+ T-cell counts of less than 50 per cubic millimeter increased AIDS-free survival. Deferral of the initiation of ART to the first 4 weeks of the continuation phase of tuberculosis therapy in those with higher CD4+ T-cell counts reduced the risks of IRIS and other adverse events related to ART without increasing the risk of AIDS or death. (Funded by the U.S. Presidents Emergency Plan for AIDS Relief and others; SAPIT ClinicalTrials.gov number, NCT00398996.).

Genital inflammation and the risk of HIV acquisition in women

BACKGROUND Women in Africa, especially young women, have very high human immunodeficiency virus (HIV) incidence rates that cannot be fully explained by behavioral risks. We investigated whether genital inflammation influenced HIV acquisition in this group. METHODS Twelve selected cytokines, including 9 inflammatory cytokines and chemokines (interleukin [IL]-1α, IL-1β, IL-6, tumor necrosis factor-α, IL-8, interferon-γ inducible protein-10 [IP-10], monocyte chemoattractant protein-1, macrophage inflammatory protein [MIP]-1α, MIP-1β), hematopoietic IL-7, and granulocyte macrophage colony-stimulating factor, and regulatory IL-10 were measured prior to HIV infection in cervicovaginal lavages from 58 HIV seroconverters and 58 matched uninfected controls and in plasma from a subset of 107 of these women from the Centre for the AIDS Programme of Research in South Africa 004 tenofovir gel trial. RESULTS HIV seroconversion was associated with raised genital inflammatory cytokines (including chemokines MIP-1α, MIP-1β, and IP-10). The risk of HIV acquisition was significantly higher in women with evidence of genital inflammation, defined by at least 5 of 9 inflammatory cytokines being raised (odds ratio, 3.2; 95% confidence interval, 1.3-7.9; P = .014). Genital cytokine concentrations were persistently raised (for about 1 year before infection), with no readily identifiable cause despite extensive investigation of several potential factors, including sexually transmitted infections and systemic cytokines. CONCLUSIONS Elevated genital concentrations of HIV target cell-recruiting chemokines and a genital inflammatory profile contributes to the high risk of HIV acquisition in these African women.

Symptomatic vaginal discharge is a poor predictor of sexually transmitted infections and genital tract inflammation in high-risk women in South Africa

BACKGROUND Diagnosis and treatment of sexually transmitted infections (STIs) is a public health priority, particularly in regions where the incidence of human immunodeficiency virus (HIV) infection is high. In most developing countries, STIs are managed syndromically. We assessed the adequacy of syndromic diagnosis of STIs, compared with laboratory diagnosis of STIs, and evaluated the association between STI diagnosis and the risk of HIV acquisition in a cohort of high-risk women. METHODS HIV-uninfected high-risk women (n = 242) were followed for 24 months. Symptoms of STIs were recorded, and laboratory diagnosis of common STI pathogens was conducted every 6 months. Forty-two cytokines were measured by Luminex in cervicovaginal lavage specimens at enrollment. Human immunodeficiency virus type 1 (HIV-1) infection was evaluated monthly. RESULTS Only 12.3% of women (25 of 204) who had a laboratory-diagnosed, discharge-causing STI had clinically evident discharge. Vaginal discharge was thus a poor predictor of laboratory-diagnosed STIs (sensitivity, 12.3%; specificity, 93.8%). Cervicovaginal cytokine concentrations did not differ between women with asymptomatic STIs and those with symptomatic STIs and were elevated in women with asymptomatic STIs, compared with women with no STIs or bacterial vaginosis. Although laboratory-diagnosed STIs were associated with increased risk of HIV infection (hazard ratio, 3.3 [95% confidence interval, 1.5-7.2)], clinical symptoms were not. CONCLUSIONS Syndromic STI diagnosis dependent on vaginal discharge was poorly predictive of laboratory-diagnosed STI. Laboratory-diagnosed STIs were associated with increased susceptibility to HIV acquisition, while vaginal discharge was not.

Preventing HIV Infection in Women: A global Health Imperative

Women account for approximately one-half of all human immunodeficiency virus (HIV) infections worldwide. Sexual transmission is the dominant mode of HIV transmission to women, and there is a concomitant associated epidemic of transmission to infants. The majority of HIV infections in women are in sub-Saharan Africa, with a disproportionate burden in young women <25 years of age. Acquisition and prevention of HIV infection in women is complex and influenced by biological, behavioral, and structural factors. Efforts to reduce the incidence of HIV infection among women in sub-Saharan African could play a substantial role in altering global trajectories of HIV infection. Increasing access to sexual and reproductive health services, addressing gender-based violence and social instability, reducing poverty and the need to engage in sex for survival, and encouraging greater male responsibility are critical short-to-medium-term interventions. Efforts to find a microbicide and HIV vaccine need to be matched with efforts to deepen understanding of acquisition of HIV in the female genital tract to inform development of targeted molecules for prevention of HIV infection.

Tenofovir Gel for the Prevention of Herpes Simplex Virus Type 2 Infection

BACKGROUND Globally, herpes simplex virus type 2 (HSV-2) infection is the most common cause of genital ulcer disease. Effective prevention strategies for HSV-2 infection are needed to achieve the goals of the World Health Organization global strategy for the prevention and control of sexually transmitted infections. METHODS We assessed the effectiveness of pericoital tenofovir gel, an antiviral microbicide, in preventing HSV-2 acquisition in a subgroup of 422 HSV-2-negative women enrolled in the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 study, a double-blind, randomized, placebo-controlled trial. Incident HSV-2 cases were identified by evidence of seroconversion on an HSV-2 IgG enzyme-linked immunosorbent assay between study enrollment and exit. A confirmatory analysis was performed by Western blot testing. RESULTS The HSV-2 incidence rate was 10.2 cases per 100 person-years (95% confidence interval [CI], 6.8 to 14.7) among 202 women assigned to tenofovir gel, as compared with 21.0 cases per 100 person-years (95% CI, 16.0 to 27.2) among 222 women assigned to placebo gel (incidence rate ratio, 0.49; 95% CI, 0.30 to 0.77; P=0.003). The HSV-2 incidence rate among the 25 women with vaginal tenofovir concentrations of 10,000 ng per milliliter or more was 5.7 cases per 100 person-years, as compared with 15.5 cases per 100 person-years among the 103 women with no detectable vaginal tenofovir (incidence rate ratio, 0.37; 95% CI, 0.04 to 1.51; P=0.14). As confirmed by Western blot testing, there were 16 HSV-2 seroconversions among women assigned to tenofovir gel as compared with 36 among those assigned to the placebo gel (incidence rate ratio, 0.45; 95% CI, 0.23 to 0.82; P=0.005). CONCLUSIONS In this study in South Africa, pericoital application of tenofovir gel reduced HSV-2 acquisition in women. (Funded by the U.S. Agency for International Development and others; ClinicalTrials.gov number, NCT00441298.).

Transmission networks and risk of HIV infection in KwaZulu-Natal, South Africa: a community-wide phylogenetic study

BACKGROUND The incidence of HIV infection in young women in Africa is very high. We did a large-scale community-wide phylogenetic study to examine the underlying HIV transmission dynamics and the source and consequences of high rates of HIV infection in young women in South Africa. METHODS We did a cross-sectional household survey of randomly selected individuals aged 15-49 years in two neighbouring subdistricts (one urban and one rural) with a high burden of HIV infection in KwaZulu-Natal, South Africa. Participants completed structured questionnaires that captured general demographic, socioeconomic, psychosocial, and behavioural data. Peripheral blood samples were obtained for HIV antibody testing. Samples with HIV RNA viral load greater than 1000 copies per mL were selected for genotyping. We constructed a phylogenetic tree to identify clusters of linked infections (defined as two or more sequences with bootstrap or posterior support ≥90% and genetic distance ≤4·5%). FINDINGS From June 11, 2014, to June 22, 2015, we enrolled 9812 participants, 3969 of whom tested HIV positive. HIV prevalence (weighted) was 59·8% in 2835 women aged 25-40 years, 40·3% in 1548 men aged 25-40 years, 22·3% in 2224 women younger than 25 years, and 7·6% in 1472 men younger than 25 years. HIV genotyping was done in 1589 individuals with a viral load of more than 1000 copies per mL. In 90 transmission clusters, 123 women were linked to 103 men. Of 60 possible phylogenetically linked pairings with the 43 women younger than 25 years, 18 (30·0%) probable male partners were younger than 25 years, 37 (61·7%) were aged 25-40 years, and five (8·3%) were aged 41-49 years: mean age difference 8·7 years (95% CI 6·8-10·6; p<0·0001). For the 92 possible phylogenetically linked pairings with the 56 women aged 25-40 years, the age difference dropped to 1·1 years (95% CI -0·6 to 2·8; p=0·111). 16 (39·0%) of 41 probable male partners linked to women younger than 25 years were also linked to women aged 25-40 years. Of 79 men (mean age 31·5 years) linked to women younger than 40 years, 62 (78·5%) were unaware of their HIV-positive status, 76 (96·2%) were not on antiretroviral therapy, and 29 (36·7%) had viral loads of more than 50 000 copies per mL. INTERPRETATION Sexual partnering between young women and older men, who might have acquired HIV from women of similar age, is a key feature of the sexual networks driving transmission. Expansion of treatment and combination prevention strategies that include interventions to address age-disparate sexual partnering is crucial to reducing HIV incidence and enabling Africa to reach the goal of ending AIDS as a public health threat. FUNDING Presidents Emergency Program for AIDS Relief, US Centers for Disease Control and Prevention, South African Medical Research Council, and MAC AIDS Fund.

Strengthening HIV services for pregnant women: an opportunity to reduce maternal mortality rates in Southern Africa/sub-Saharan Africa

Please cite this paper as: Moodley J, Pattinson R, Baxter C, Sibeko S, Abdool Karim Q. Strengthening HIV services for pregnant women: an opportunity to reduce maternal mortality rates in Southern Africa/sub‐Saharan Africa. BJOG 2011;118:219–225.

Overview of microbicides for the prevention of human immunodeficiency virus.

Human immunodeficiency virus (HIV) prevention tools that women can use and control are urgently needed. Microbicides are chemical products applied to the vagina or rectum to prevent the sexual transmission of HIV. Four classes of candidate microbicides have been tested to date: those that (1) enhance the natural defences in the vagina to inactivate HIV; (2) inactivate HIV in the vagina; (3) prevent HIV from attaching to, and fusing with, the host cells; and (4) prevent HIV from replicating in genital tract host cells. Despite numerous disappointing efficacy trial results over the past 20 years, substantial progress is now being made in microbicide development after the release of the CAPRISA 004 trial, which provided proof-of-concept that topical antiretroviral microbicides can prevent sexual transmission of HIV and herpes simplex type-2 infection. Microbicides, which fill an important gap for women-controlled prevention methods, have the potential to alter the course of the HIV pandemic.