Browsing by Author "Sibeko, Sengeziwe."

Now showing 1 - 19 of 19

CAPRISA 004 tenofovir microbicide trial: no impact of tenofovir gel on the HIV transmission bottleneck.
(Oxford University Press., 2011) Valley-Omar, Ziyaad.; Sibeko, Sengeziwe.; Anderson, Jeffrey A.; Goodier, Sarah A.; Werner, Lise.; Arney, Leslie.; Naranbhai, Vivek.; Treurnicht, Florette K.; Abrahams, Melissa-Rose.; Bandawe, Gama P.; Swanstrom, Ronald.; Abdool Karim, Salim Safurdeen.; Abdool Karim, Quarraisha.; Williamson, Carolyn.
Alterations of the genital mucosal barrier may influence the number of viruses transmitted from a human immunodeficiency virus–infected source host to the newly infected individual. We used heteroduplex tracking assay and single-genome sequencing to investigate the effect of a tenofovir-based microbicide gel on the transmission bottleneck in women who seroconverted during the CAPRISA 004 microbicide trial. Seventy-seven percent (17 of 22; 95% confidence interval [CI], 56%–90%) of women in the tenofovir gel arm were infected with a single virus compared with 92% (13 of 14; 95% CI, 67%–>99%) in the placebo arm (P = .37). Tenofovir gel had no discernable impact on the transmission bottleneck.
Contraception and pregnancy in microbicide trials.
(Elsevier., 2012) Sibeko, Sengeziwe.; Cohen, Gabriel M.; Moodley, Jagidesa.
The distinctive feature of the human immunodeficiency virus (HIV) epidemic in Sub-Saharan Africa is the burden on women, in particular young women of reproductive age. Consequently, most late-phase effectiveness microbicide clinical trials are conducted in sub-Saharan Africa where fertility rates are high. Because late-phase clinical trials are conducted over prolonged periods of time, women participating in these trials may fall pregnant during the trial. Their unborn babies may be exposed to a drug whose teratogenic potential is unknown if the investigational drug is not withdrawn. High pregnancy rates in such trials may compromise statistical integrity, as women will be withdrawn from the study drug for the duration of the pregnancy. It is therefore imperative for microbicide trials to implement effective contraceptive and pregnancy management programmes that maintain low pregnancy rates and the safety of unborn babies while not compromising the conduct and statistical integrity of the trial.
Contraceptive choices, pregnancy rates, and outcomes in a microbicide trial.
(Lippincott Williams & Wilkins., 2011) Sibeko, Sengeziwe.; Baxter, Cheryl.; Abdool Karim, Quarraisha.; Abdool Karim, Salim Safurdeen.; Yende Zuma, Nonhlanhla.
OBJECTIVE: Women who become pregnant during the conduct of biomedical human immunodeficiency virus prevention trials are taken off the study product for safety reasons. High pregnancy rates can compromise statistical integrity in these trials. The comprehensive contraceptive curriculum developed for the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 trial was evaluated for its ability to enhance contraceptive uptake, reduce pregnancy rates, and preserve statistical integrity. METHODS: Contraceptive- and pregnancy-related eligibility criteria were specified in the protocol. We enrolled women who opted for a nonbarrier method of contraceptive and provided hormonal contraceptives onsite at no cost. At each monthly study visit, we provided pregnancy prevention counseling and performed pregnancy testing. Study product was withheld on pregnancy diagnosis, but women continued with monthly follow-up. RESULTS: Contraceptive use was high throughout the study with 100% uptake at baseline and 94.71% use after a mean of 18 months follow-up at exit. Injectable progestins, particularly medroxyprogesterone acetate, remained the preferred choice of contraceptive. After 30 months of follow-up, 54 pregnancies were reported out of 889 participants, giving a pregnancy incidence rate of 3.95 per 100 woman-years (95% confidence interval 2.96–5.17). Of all pregnancies, two thirds (64.81%) resulted in a full-term live birth, whereas 18.52% and 11.11% pregnancies culminated as miscarriage and terminated pregnancies, respectively. There were no congenital anomalies in the early neonatal period. Pregnancies resulted in 1.56% of woman-years of study follow-up lost as a result of temporary product withdrawal. CONCLUSION: The CAPRISA 004 contraceptive curriculum was an effective strategy for maintaining low pregnancy rates, thereby minimizing product withdrawal and loss of follow-up time.
The development of CD4 binding site antibodies during HIV-1 infection.
(American Society for Microbiology., 2012) Lynch, Rebecca M.; Tran, Lillian.; Louder, Mark K.; Schmidt, Stephen D.; Cohen, Myron S.; DerSimonian, Rebecca.; Euler, Zelda.; Gray, Elin Solomonovna.; Abdool Karim, Salim Safurdeen.; Kirchherr, Jennifer.; Montefiori, David Charles.; Sibeko, Sengeziwe.; Soderberg, Kelly.; Tomaras, Georgia D.; Yang, Zhi-Yong.; Nabel, Gary J.; Schuitemaker, Hanneke.; Morris, Lynn.; Haynes, Barton F.; Mascola, John R.
Broadly neutralizing antibodies to the CD4 binding site (CD4bs) of gp120 are generated by some HIV-1-infected individuals, but little is known about the prevalence and evolution of this antibody response during the course of HIV-1 infection. We analyzed the sera of 113 HIV-1 seroconverters from three cohorts for binding to a panel of gp120 core proteins and their corresponding CD4bs knockout mutants. Among sera collected between 99 and 258 weeks post-HIV-1 infection, 88% contained antibodies to the CD4bs and 47% contained antibodies to resurfaced stabilized core (RSC) probes that react preferentially with broadly neutralizing CD4bs antibodies (BNCD4), such as monoclonal antibodies (MAbs) VRC01 and VRC-CH31. Analysis of longitudinal serum samples from a subset of 18 subjects revealed that CD4bs antibodies to gp120 arose within the first 4 to 16 weeks of infection, while the development of RSC-reactive antibodies was more varied, occurring between 10 and 152 weeks post-HIV-1 infection. Despite the presence of these antibodies, serum neutralization mediated by RSC-reactive antibodies was detected in sera from only a few donors infected for more than 3 years. Thus, CD4bs antibodies that bind a VRC01-like epitope are often induced during HIV-1 infection, but the level and potency required to mediate serum neutralization may take years to develop. An improved understanding of the immunological factors associated with the development and maturation of neutralizing CD4bs antibodies during HIV-1 infection may provide insights into the requirements for eliciting this response by vaccination.
Effectiveness and safety of tenofovir gel, an antiretroviral microbicide, for the prevention of HIV infection in women.
(American Association for the Advancement of Science., 2010) Abdool Karim, Salim Safurdeen.; Abdool Karim, Quarraisha.; Fröhlich, Janet Ann.; Grobler, Anna Christina.; Baxter, Cheryl.; Mansoor, Leila Essop.; Kharsany, Ayesha Bibi Mahomed.; Sibeko, Sengeziwe.; Mlisana, Koleka Patience.; Omar, Zaheen.; Gengiah, Tanuja Narayansamy.; Maarschalk, Silvia.; Arulappan, Natasha.; Mlotshwa, Mukelisiwe.; Morris, Lynn.; Taylor, Douglas.
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.
HIV disease progression in seroconvertors from the CAPRISA 004 tenofovir gel pre-exposure prophylaxis trial.
(Lippincott Williams & Wilkins., 2015) Garrett, Nigel Joel.; Werner, Lise.; Naicker, Nivashnee.; Naranbhai, Vivek.; Sibeko, Sengeziwe.; Samsunder, Natasha.; Gray, Clive M.; Williamson, Carolyn.; Morris, Lynn.; Abdool Karim, Quarraisha.; Abdool Karim, Salim Safurdeen.
Abstract available in pdf.
Innate immune activation enhances HIV acquisition in women, diminishing the effectiveness of tenofovir microbicide gel.
(Oxford University Press., 2011) Naranbhai, Vivek.; Abdool Karim, Salim Safurdeen.; Altfeld, Marcus.; Samsunder, Natasha.; Durgiah, Raveshni.; Sibeko, Sengeziwe.; Abdool Karim, Quarraisha.; Carr, William Henry.
The antiretroviral agent, tenofovir, formulated as a vaginal microbicide gel, reduces human immunodeficiency virus (HIV) acquisition by 39% in women. This study assessed the role of preexisting immune activation in HIV acquisition in women from the CAPRISA 004 trial, to identify potential strategies to increase the effectiveness of tenofovir gel. Systemic cytokine and cellular immune mediators (platelets and natural killer [NK] cells) were assessed in women at high risk for HIV assigned to either tenofovir or placebo gel in the CAPRISA 004 trial. Notwithstanding tenofovir gel use, women who acquired HIV had significantly higher systemic innate immune activation prior to infection than women who remained uninfected. Activation of both soluble (cytokine) and cellular (NK cells) immune mediators were associated with HIV acquisition, individually or in combination. Hence, an innate immune activation suppressant could be added to tenofovir gel as a potential combination gel strategy in developing the next generation of higher efficacy antiretroviral microbicides.
Killer-cell Immunoglobulin-like Receptor (KIR) gene profiles modify HIV disease course, not HIV acquisition in South African women.
(BioMed Central., 2016) Naranbhai, Vivek.; de Assis Rosa, Debra.; Werner, Lise.; Moodley, Ramona.; Hong, Heather.; Kharsany, Ayesha Bibi Mahomed.; Mlisana, Koleka Patience.; Sibeko, Sengeziwe.; Garrett, Nigel Joel.; Chopera, Denis Rutendo.; Carr, William Henry.; Abdool Karim, Quarraisha.; Hill, Adrian V. S.; Abdool Karim, Salim Safurdeen.; Altfeld, Marcus.; Gray, Clive M.; Ndung'u, Peter Thumbi.
Abstract available in PDF file.
Lower concentrations of chemotactic cytokines and soluble innate factors in the lower female genital tract associated with the use of injectable hormonal contraceptive.
(Elsevier., 2015) Ngcapu, Sinaye.; Masson, Lindi.; Sibeko, Sengeziwe.; Werner, Lise.; McKinnon, Lyle R.; Mlisana, Koleka Patience.; Shey, Muki Shehu.; Samsunder, Natasha.; Abdool Karim, Salim Safurdeen.; Abdool Karim, Quarraisha.; Passmore, Jo-Ann Shelley.
Abstract available in pdf.
The Neutralization Breadth of HIV-1 Develops Incrementally over Four Years and Is Associated with CD4+ T Cell Decline and High Viral Load during Acute Infection.
(American Society for Microbiology., 2011) Gray, Elin Solomonovna.; Madiga, Maphuti C.; Hermanus, Tandile.; Moore, Penelope L.; Wibmer, Constantinos Kurt.; Tumba, Nancy Lola.; Werner, Lise.; Mlisana, Koleka Patience.; Sibeko, Sengeziwe.; Williamson, Carolyn.; Abdool Karim, Salim Safurdeen.; Morris, Lynn.
An understanding of how broadly neutralizing activity develops in HIV-1-infected individuals is needed to guide vaccine design and immunization strategies. Here we used a large panel of 44 HIV-1 envelope variants (subtypes A, B, and C) to evaluate the presence of broadly neutralizing antibodies in serum samples obtained 3 years after seroconversion from 40 women enrolled in the CAPRISA 002 acute infection cohort. Seven of 40 participants had serum antibodies that neutralized more than 40% of viruses tested and were considered to have neutralization breadth. Among the samples with breadth, CAP257 serum neutralized 82% (36/44 variants) of the panel, while CAP256 serum neutralized 77% (33/43 variants) of the panel. Analysis of longitudinal samples showed that breadth developed gradually starting from year 2, with the number of viruses neutralized as well as the antibody titer increasing over time. Interestingly, neutralization breadth peaked at 4 years postinfection, with no increase thereafter. The extent of cross-neutralizing activity correlated with CD4+T cell decline, viral load, and CD4+T cell count at 6 months postinfection but not at later time points, suggesting that early events set the stage for the development of breadth. However, in a multivariate analysis, CD4 decline was the major driver of this association, as viral load was not an independent predictor of breadth. Mapping of the epitopes targeted by cross-neutralizing antibodies revealed that in one individual these antibodies recognized the membrane-proximal external region (MPER), while in two other individuals, cross-neutralizing activity was adsorbed by monomeric gp120 and targeted epitopes that involved the N-linked glycan at position 332 in the C3 region. Serum antibodies from the other four participants targeted quaternary epitopes, at least 2 of which were PG9/16-like and depended on the N160 and/or L165 residue in the V2 region. These data indicate that fewer than 20% of HIV-1 subtype C-infected individuals develop antibodies with cross-neutralizing activity after 3 years of infection and that these antibodies target different regions of the HIV-1 envelope, including as yet uncharacterized epitopes.
Potent and Broad Neutralization of HIV-1 Subtype C by Plasma Antibodies Targeting a Quaternary Epitope Including Residues in the V2 Loop.
(American Society for Microbiology., 2010) Moore, Penelope L.; Gray, Elin Solomonovna.; Sheward, Daniel J.; Madiga, Maphuti C.; Ranchobe, Nthabeleng.; Honnen, William J.; Nonyane, Molati.; Tumba, Nancy Lola.; Hermanus, Tandile.; Sibeko, Sengeziwe.; Mlisana, Koleka Patience.; Abdool Karim, Salim Safurdeen.; Williamson, Carolyn.; Pinter, Abraham.; Morris, Lynn.; Lai, Zhong.
The targets of broadly cross-neutralizing (BCN) antibodies are of great interest in the HIV vaccine field. We have identified a subtype C HIV-1-superinfected individual, CAP256, with high-level BCN activity, and characterized the antibody specificity mediating breadth. CAP256 developed potent BCN activity peaking at 3 years postinfection, neutralizing 32 (76%) of 42 heterologous viruses, with titers of antibodies against some viruses exceeding 1:10,000. CAP256 showed a subtype bias, preferentially neutralizing subtype C and A viruses over subtype B viruses. CAP256 BCN serum targeted a quaternary epitope which included the V1V2 region. Further mapping identified residues F159, N160, L165, R166, D167, K169, and K171 (forming the FN/LRD-K-K motif) in the V2 region as crucial to the CAP256 epitope. However, the fine specificity of the BCN response varied over time and, while consistently dependent on R166 and K169, became gradually less dependent on D167 and K171, possibly contributing to the incremental increase in breadth over 4 years. The presence of an intact FN/LRD-K-K motif in heterologous viruses was associated with sensitivity, although the length of the adjacent V1 loop modulated the degree of sensitivity, with a shorter V1 region significantly associated with higher titers. Repair of the FN/LRD-K-K motif in resistant heterologous viruses conferred sensitivity, with titers sometimes exceeding 1:10,000. Comparison of the CAP256 epitope with that of the PG9/PG16 monoclonal antibodies suggested that these epitopes overlapped, adding to the mounting evidence that this may represent a common neutralization target that should be further investigated as a potential vaccine candidate.
Preservation HIV-1–specific IFNg+ CD4+ T-Cell responses in breakthrough infections after exposure to tenofovir gel in the CAPRISA 004 microbicide trial.
(Lippincott Williams & Wilkins., 2011) Mureithi, Marianne W.; Poole, Danielle.; Naranbhai, Vivek.; Reddy, Shabashini.; Mkhwanazi, Nompumelelo Prudence.; Sibeko, Sengeziwe.; Werner, Lise.; Abdool Karim, Quarraisha.; Abdool Karim, Salim Safurdeen.; Ndung'u, Peter Thumbi.; Altfeld, Marcus.
Abstract: The Centre for the AIDS Program of Research in South Africa 004 trial demonstrated reduction of sexual HIV-1 acquisition in women using a vaginal microbicide containing tenofovir. A better understanding of the consequences of antiretroviral-containing microbicides for immune responses in individuals with intercurrent HIV-1 infection is needed for future trials combining the use of microbicides with HIV-1 vaccines. Investigation of immune responses in women who acquired HIV-1 although using tenofovir gel showed significantly higher (P = 0.01) Gag-specific IFNγ+ CD4+ T-cell responses. The use of tenofovir-containing gel around the time of infection can modulate HIV-1 immunity, and these immunological changes need to be considered in future trials combining vaccines and microbicides.
Preventing HIV infection in women: A global health imperative.
(Oxford University Press on behalf of University of Chicago Press., 2010) Abdool Karim, Quarraisha.; Sibeko, Sengeziwe.; Baxter, Cheryl.
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.
Recommendations for the follow-up of study participants with breakthrough HIV infections during HIV/AIDS biomedical prevention studies.
(Wolters Kluwer Health., 2013) Etter, Paige.; Landovitz, Raphael J.; Sibeko, Sengeziwe.; Sobieszczyk, Magdalena E.; Riddler, Sharon Anne.; Karg, Carissa.; Tsibris, Athe.; Schouten, Jeffrey.
Objective: To facilitate collection of cumulative data on longitudinal HIV disease outcomes during HIV prevention studies by developing recommendations for follow-up of the relatively few study participants with breakthrough infections. Design: We formed a working group to compare and contrast the various approaches taken in recent HIV prevention trials, to summarize the advantages and disadvantages associated with each, and to explore the feasibility of developing protocols for the long-term follow-up of seroconverters. Methods: We reviewed study designs, objectives, and assessments in 15 interventional studies that followed HIV seroconverters. Protocol team members joined discussions of the various approaches and developed recommendations. Results: Most HIV prevention clinical trials share a core set of objectives, including the description/comparison of virological, immunological, and clinical course of HIV, and sometimes a comparison of preseroconversion and postseroconversion behavior. Long-term follow-up of seroconverters can be conducted in separate studies if the transition from parent protocol is effectively managed. Conclusion: We recommend the development of harmonized seroconverter protocols. Although specific research questions in the postseroconversion period may differ depending on prevention modality, harmonizing key evaluations would create an opportunity to ask overarching questions that inform the prevention field with respect to design and implementation of future combination prevention studies. Follow-up immediately postseroconversion should be conducted in the parent protocol before roll over into a follow-up protocol. Development of specimen repositories with ample volumes for future assays, standardized definitions of infection, diagnosis and seroconversion dates, and harmonization of study objectives and sample collections at key time points are important.
Recruitment of high risk women for HIV prevention trials: baseline HIV prevalence and sexual behavior in the CAPRISA 004 tenofovir gel trial.
(Biomed Central, 2010) Abdool Karim, Quarraisha.; Kharsany, Ayesha Bibi Mahomed.; Fröhlich, Janet Ann.; Baxter, Cheryl.; Yende Zuma, Nonhlanhla.; Mansoor, Leila Essop.; Mlisana, Koleka Patience.; Maarschalk, Silvia.; Arulappan, Natasha.; Grobler, Anna Christina.; Sibeko, Sengeziwe.; Omar, Zaheen.; Gengiah, Tanuja Narayansamy.; Mlotshwa, Mukelisiwe.; Samsunder, Natasha.; Abdool Karim, Salim Safurdeen.
Background: Young women in sub-Saharan Africa bear a disproportionate burden of HIV infection compared to men but have limited options to reduce their HIV risk. Microbicides could fill an important HIV prevention gap for sexually active women who are unable to successfully negotiate mutual monogamy or condom use. Purpose: This paper describes the baseline sample characteristics in the CAPRISA 004 trial which assessed the safety and effectiveness of the vaginal microbicide, 1% tenofovir gel for HIV prevention in South Africa. Methods: This analysis assessed the baseline demographic, clinical and sexual behavior data of women screened and enrolled into the trial. The characteristics were summarized using descriptive summary measures; expressed as means and percent for categorical variables. Results: HIV prevalence at screening was 25.8% [95% Confidence Interval (CI):23.9-27.7). Of the 889 eligibly enrolled women who contributed follow-up data, rural participants recruited from a family planning (FP) clinic were younger, more likely to be living apart from their regular partner, reported lower coital frequency, had lower condom use (p < 0.001). In contrast, urban participants recruited from a sexually transmitted disease (STD) clinic reported higher numbers of lifetime sexual partners, new partners in the last 30 days and receiving money in exchange for sex (p < 0.001). Conclusion: The populations selected provide suitable diverse target groups for HIV prevention intervention studies.
Safety of tenofovir gel, a vaginal microbicide, in South African women: results of the CAPRISA 004 Trial.
(International Medical Press., 2012) Sokal, David C.; Abdool Karim, Quarraisha.; Sibeko, Sengeziwe.; Yende Zuma, Nonhlanhla.; Mansoor, Leila Essop.; Baxter, Cheryl.; Grobler, Anna Christina.; Fröhlich, Janet Ann.; Kharsany, Ayesha Bibi Mahomed.; Miya, Nomsa.; Mlisana, Koleka Patience.; Maarschalk, Silvia.; Abdool Karim, Salim Safurdeen.
Background: Tenofovir gel, used vaginally before and after coitus, reduced women’s acquisition of HIV by 39%. This is a safety assessment of tenofovir gel, including renal, bone, gastrointestinal, genital and haematological parameters. Methods: In the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004, a double-blind, randomized placebo-controlled trial, 445 of the 889 eligibly enrolled women were assigned to tenofovir gel. All participants were advised to use the gel vaginally only, with one dose of gel within 12 h before and a second dose as soon as possible after sex, with no more than two doses in 24 h. Clinical and laboratory safety data were collected at monthly and quarterly visits, respectively. Genital assessments were undertaken at enrolment and quarterly thereafter, or as indicated. Results: Women assigned to tenofovir gel were exposed to an average monthly vaginal dose of 240 mg of tenofovir (six applications). In total, six women, three in each group, had mild creatinine elevations, all of which occurred in July/August 2008. The incidence of anaemia was 3.5 and 3.8 per 100 women-years in tenofovir and placebo groups, respectively (P=0.80). Of the six women (four tenofovir and two placebo) experiencing bone fractures, none were associated with abnormal phosphate or calcium values. The proportion of women with diarrhoea was higher in the tenofovir gel group (17% versus 11%; P=0.026). There was no significant increase of any genital adverse event in the tenofovir group. Conclusions: No significant renal, haematological, genital or bone effects were associated with the use of tenofovir gel. Aside from a puzzling increase in diarrhoea, tenofovir gel has an excellent safety profile.
Sensitive tenofovir resistance screening of HIV-1 from the genital and blood compartments of women with breakthrough infections in the CAPRISA 004 tenofovir gel trial.
(Oxford University Press., 2014) Wei, Xierong.; Hunt, Gillian.; Abdool Karim, Salim Safurdeen.; Naranbhai, Vivek.; Sibeko, Sengeziwe.; Abdool Karim, Quarraisha.; Li, Jin-fen.; Kashuba, Angela D. M.; Werner, Lise.; Passmore, Jo-Ann Shelley.; Morris, Lynn.; Heneine, Walid.; Johnson, Jeffrey A.
The Centre for the AIDS Programme of Research in South Africa 004 (CAPRISA 004) study demonstrated that vaginally applied tenofovir gel is a promising intervention for protecting women from sexually acquiring human immunodeficiency virus (HIV). However, the potential for emergence of tenofovir resistance remains a concern in women who seroconvert while using the gel despite the lack of plasma virus resistance as assessed by population sequencing during the trial. We applied highly sensitive polymerase chain reaction-based assays to screen for tenofovir resistance in plasma and vaginal swab specimens. The absence of mutation detection suggested little immediate risk of tenofovir-resistant HIV-1 emergence and forward transmission in settings in which gel users are closely monitored for HIV seroconversion.
Strengthening HIV services for pregnant women: an opportunity to reduce maternal mortality rates in Southern Africa/Sub-Saharan Africa.
(Wiley-Blackwell., 2010) Moodley, Jagidesa.; Pattinson, R. C.; Baxter, Cheryl.; Sibeko, Sengeziwe.; Abdool Karim, Quarraisha.
Reliable data from South Africa emanating from WHO recommendations for the Safe Motherhood programme underscores HIV/AIDS as the most common cause of maternal deaths. The strengthening of HIV services for pregnant women especially in countries with a high burden of HIV infection will reduce HIV-related and un-related maternal mortality rates. High-quality and complete data on maternal deaths is a critical foundation for reliably monitoring temporal trends in maternal deaths, and causes thereof, but needs substantial strengthening in many resource-constrained settings. HIV/AIDS is an increasing contributor to direct and indirect causes of maternal deaths in sub-Saharan Africa. A review of published data on maternal deaths and its association with HIV shows that reliable data come from the Confidential Enquiries into Maternal Deaths from South Africa, population-based surveys in sentinel populations, and facility-based data. Despite an increase in knowledge of the HIV status of pregnant women and the initiation of antiretroviral treatment, reversals in trends towards increased maternal deaths are not being observed. The strengthening of HIV services provides an opportunity to alter HIV epidemic trajectories and reduce maternal deaths.
Women with pregnancies had lower adherence to 1% Tenofovir vaginal gel as HIV preexposure prophylaxis in CAPRISA 004, a phase IIB randomized-controlled trial.
(Plos., 2013-03) Matthews, Lynn T.; Sibeko, Sengeziwe.; Mansoor, Leila Essop.; Yende Zuma, Nonhlanhla.; Bangsberg, David R.; Abdool Karim, Quarraisha.
Background: Antiretroviral prophylaxis may be a critical strategy to reduce periconception HIV transmission. Maximizing the benefit of periconception pharmacologic HIV risk-reduction requires an understanding of the links between pregnancy and adherence to this prevention strategy. Methods: We assessed study gel adherence among women with pregnancies compared to women without pregnancies enrolled in the CAPRISA 004 phase IIB trial of 1% vaginal tenofovir gel. Pregnancy was assessed with monthly urine tests. Adherence was measured monthly and defined as proportion of sex acts covered by two returned, used applicators based on pre- and post-coital dosing. High adherence was defined as a median adherence score of >80%, that is, more than 80% of sex acts were covered by two applications of study gel. A multivariate generalized estimating equations (GEE) model with a binomial distribution was used to assess covariates associated with high adherence (>80%) over time. Median adherence before and after pregnancy was compared using Wilcoxon signed rank test. Results: Among 868 women, 53 had at least 1 pregnancy (4.06 per 100 woman years, 95% CI: 3.04, 5.31). Women with pregnancies had lower median adherence compared to women without pregnancies (50% [IQR: 45–83] vs. 60% [IQR: 50–100], p = 0.02). Women with pregnancies also had a 48% lower odds of high adherence compared to women without pregnancies when adjusting for confounders (aOR 0.52, 95%CI: 0.41–0.66, p<0.0001). Among women with pregnancies, adherence before and after pregnancy was not different (50% [IQR: 46–83] vs. 55% [IQR: 20–100], p = 0.68). Conclusions: Women with pregnancies were less likely to have high adherence to study gel compared to women without pregnancies. Understanding these differences may inform findings from HIV prevention trials and future implementation of antiretroviral prophylaxis for at-risk women who choose to conceive. The protocol for the parent trial is registered on ClinicalTrials.gov, NCT00441298, http://www.clinicaltrials.gov/ct2/show/NCT00441298.