HIV Protective Efficacy and Correlates of Tenofovir Blood Concentrations in a Clinical Trial of PrEP for HIV Prevention

Background: Antiretroviral pre-exposure prophylaxis (PrEP) is a novel HIV prevention strategy for which adherence is a known determinant of efficacy. Blood concentrations of PrEP medications are one objective marker of adherence. Methods: In a placebo-controlled PrEP efficacy trial of tenofovir disoproxil fumarate (TDF) and TDF with emtricitabine (FTC/TDF) among 4747 African women and men with an HIV-infected partner, we measured plasma tenofovir concentrations from participants in the active PrEP arms: 29 HIV seroconverters (cases) and 196 randomly selected controls who remained uninfected. Results: Among controls, 71% of visits had tenofovir concentrations >40 ng/mL, consistent with steady-state daily dosing, compared with 21% of cases at the visit HIV was first detected. Pill count data indicated that 96% of controls and 66% of cases had >80% adherence for these same visits. The estimated protective effect of PrEP against HIV, based on concentrations >40 ng/mL, was 88% (95% confidence interval: 60 to 96, P 40 ng/mL at month 1, 75% maintained this concentration at month 12. Only 5 of 29 seroconverters seemed to be consistently adherent to PrEP. Tenofovir concentrations >40 ng/mL were associated with older age and shorter time on study; concentrations ≤40 ng/mL occurred more commonly when participants reported no sex with their HIV-infected partner. Conclusions: Plasma concentrations of tenofovir consistent with daily dosing were highly predictive of protection from HIV acquisition. Most of those who took PrEP seemed to have high and consistent adherence

Comparing Papanicolau smear, visual inspection with acetic acid and human papillomavirus cervical cancer screening methods among HIV-positive women by immune status and antiretroviral therapy

Background: A rigorous comparison of cervical cancer screening methods utilizing data on immune status, antiretroviral therapy (ART) and colposcopy-directed biopsy has not been performed among HIV-positive women. Methods: Between June and November 2009, 500 HIV-positive women were enrolled at an HIV treatment clinic in Nairobi, Kenya, and underwent Papanicolau (Pap) smear, visual inspection with acetic acid (VIA), human papillomavirus (HPV) and colposcopydirected biopsy (gold standard). Positive Pap smear (ASCUS, LSIL, HSIL), VIA, HPV and their combinations were compared with CIN2/3+. Sensitivity, specificity and AUC (sensitivity and 1-specificity) were compared using pairwise tests and multivariate logistic regression models that included age, CD4+ cell count and ART duration. Results:Of 500 enrolled, 498 samples were collected. On histology, there were 172 (35%) normal, 186 (37%) CIN1, 66 (13%) CIN2, 47 (9%) CIN3 and 27 (5%) indeterminate. Pap (ASCUS+) was the most sensitive screening method (92.7%), combination of both Pap (HSIL+) and VIA positive was the most specific (99.1%) and Pap (HSIL+) had the highest AUC (0.85). In multivariate analyses, CD4+ cell count of 350 cells/ml or less was associated with decreased HPV specificity (P=0.002); ART duration of less than 2 years was associated with decreased HPV (P=0.01) and VIA (P=0.03) specificity; and age less than 40 years was associated with increased VIA sensitivity (P Conclusion: Pap smear is a robust test among HIV-positive women regardless of immune status or ART duration. Results should be cautiously interpreted when using HPV among those younger, immunosuppressed or on ART less than 2 years, and when using VIA among those aged 40 years or more

Prevalence and determinants of human papillomavirus infection and cervical lesions in HIV-positive women in Kenya

Background: We assessed the association of human papillomavirus (HPV) infection and cervical intraepithelial neoplasia (CIN) with various characteristics, CD4 count and use of combination antiretroviral therapy (cART) among HIV-positive women. Methods: Cross-sectional study of 498 HIV-positive women who underwent HPV PCR-based testing, cytology, and systematic cervical biopsy. Results: In all, 68.7% of women were HPV-positive, 52.6% had high-risk (hr) HPV, and 40.2% multiple type infections. High-risk human papillomavirus-positivity did not vary significantly by age but it was negatively associated with education level. The most frequent types in 113 CIN2/3 were HPV16 (26.5%), HPV35 (19.5%), and HPV58 (12.4%). CD4 count was negatively associated with prevalence of hrHPV (Po0.001) and CIN2/3 among non-users of cART (P¼0.013). Combination antiretroviral therapies users (X2 year) had lower hrHPV prevalence (prevalence ratio (PR) vs non-users¼0.77, 95% confidence interval (CI): 0.61–0.96) and multiple infections (PR¼0.68, 95% CI: 0.53–0.88), but not fewer CIN2/3. The positive predictive value of hrHPV-positivity for CIN2/3 increased from 28.9% at age o35 years to 53.3% in X45 years. Conclusion: The burden of hrHPV and CIN2/3 was high and it was related to immunosuppression level. Combination antiretroviral therapies (X2 year) use had a favourable effect on hrHPV prevalence but cART in our population may have been started too late to prevent CIN2/3

Attitudes Toward Menstrual Suppression Among Cyclic and Continuous Contraceptive Vaginal Ring Users in Kenya

Objective: Multipurpose prevention technologies (MPTs) are developmental dual-purpose options that would provide women with a contraceptive as well as a prevention modality aimed at sexually transmitted infections. The contraceptive vaginal ring (CVR) has many properties that makes it an ideal MPT candidate. The objective of this study is to understand women’s attitudes towards menstrual suppression, a potential side effect of using a CVR, and how to address these attitudes for MPT vaginal rings in development. Materials and methods: We analyzed data derived from a subset of cohort study participants (n=45) in Thika, Kenya between January 2016- December 2018. The primary study enrolled 121 women 18-40 years with bacterial vaginosis and randomized them to cyclic or continuous CVR use for eight months. During the 6-month follow-up, a questionnaire eliciting attitudes towards menstrual suppression was administered. Responses to the menstrual suppression questionnaire between participants in the cyclic and continuous CVR use groups were compared. Likert-scale responses were summed to create a menstrual suppression attitude summary score, and a hierarchical cluster analysis was conducted to identify similarities in response patterns among all participants. Results: Totally 81.8% of continuous CVR users believed that one was less likely to get pregnant after using hormonal medication to suppress menses, compared to 47.8% of cyclic CVR users (P=0.02), and were more worried it would cause long-term health effects (86.4% vs 60.9%, p = 0.05). The menstrual suppression attitude summary score ranged from 8 to 42, with lower scores indicating negative attitudes. The summary score identified three distinct clusters. When asked if menstrual suppression effects long-term health; 100% of Cluster 3 was worried compared to 80.8% of Cluster 2 and 46.2% of Cluster 1 (p = 0.03). The average summary score among Cluster 3 (Mean = 14.8, SD = 4.6) was lower (p < 0.001) and women were more worried about discomfort during sex (p=0.05) as well as their sexual partners feeling the ring (p=0.02). Conclusion: Women are more likely to have negative attitudes if they believe menstrual suppression hinders future reproductive health. Education on cycle control and fertility could mitigate negative attitudes and improve uptake of CVRs

Testing public Bt maize events for control of stem borers in the first confined field trials in Kenya

Transgenic maize (Zea mays L), developed using modified genes from the bacterium Bacillus thuringiensis (Bt), controls stem borers without observable negative effects to humans, livestock or the environment, and is now sown on 134 million hectares globally. Bt maize could contribute to increasing maize production in Kenya. Nine public Bt maize events of cry1Ab and cry1Ba genes were tested in confined field trials site (CFTs) to assess the control of four major Kenyan stem borer species. Leaf damage rating, number of exit holes and tunnel length were scored in the field evaluations. Leaf area consumed and mortality rates among stem borers were scored in the leaf bioassays in a Biosafety Level II laboratory, located at the Kenya Agricultural Research Institute (KARI), National Agricultural Research Laboratories (NARL). Field evaluations showed that Bt maize controlled Chilo partellus with mean damage scores of 1.2 against 2.7 for the non-Bt CML216 control. Laboratory bioassays showed high control for Eldana saccharina and Sesamia calamistis, with mean larval mortality of 64 and 92%, respectively. However, substantial control was not observed for Busseola fusca. These results showed that Bt maize could control three of the four major stem borers in Kenya with mortality records of 52.7% for B. fusca, 62.3% for E. saccharina and 85.8% for S. calamistis. Additional Bt genes need to be sought and tested for effective stem borer control in all maize growing ecologies in Kenya

Regional Differences in Prevalence of HIV-1 Discordance in Africa and Enrollment of HIV-1 Discordant Couples into an HIV-1 Prevention Trial

Background: Most HIV-1 transmission in Africa occurs among HIV-1-discordant couples (one partner HIV-1 infected and one uninfected) who are unaware of their discordant HIV-1 serostatus. Given the high HIV-1 incidence among HIV-1 discordant couples and to assess efficacy of interventions for reducing HIV-1 transmission, HIV-1 discordant couples represent a critical target population for HIV-1 prevention interventions and prevention trials. Substantial regional differences exist in HIV-1 prevalence in Africa, but regional differences in HIV-1 discordance among African couples, has not previously been reported. Methodology/Principal Findings: The Partners in Prevention HSV-2/HIV-1 Transmission Trial (“Partners HSV-2 Study”), the first large HIV-1 prevention trial in Africa involving HIV-1 discordant couples, completed enrollment in May 2007. Partners HSV-2 Study recruitment data from 12 sites from East and Southern Africa were used to assess HIV-1 discordance among couples accessing couples HIV-1 counseling and testing, and to correlate with enrollment of HIV-1 discordant couples. HIV-1 discordance at Partners HSV-2 Study sites ranged from 8–31% of couples tested from the community. Across all study sites and, among all couples with one HIV-1 infected partner, almost half (49%) of couples were HIV-1 discordant. Site-specific monthly enrollment of HIV-1 discordant couples into the clinical trial was not directly associated with prevalence of HIV-1 discordance, but was modestly correlated with national HIV-1 counseling and testing rates and access to palliative care/basic health care (r = 0.74, p = 0.09). Conclusions/Significance: HIV-1 discordant couples are a critical target for HIV-1 prevention in Africa. In addition to community prevalence of HIV-1 discordance, national infrastructure for HIV-1 testing and healthcare delivery and effective community outreach strategies impact recruitment of HIV-1 discordant couples into HIV-1 prevention trials

Antiretroviral Drugs Protect Against HIV-1 Infection in Heterosexuals

BackgroundAntiretroviral preexposure prophylaxis is a promising approach for preventing human immunodeficiency virus type 1 (HIV-1) infection in heterosexual populations.MethodsWe conducted a randomized trial of oral antiretroviral therapy for use as preexposure prophylaxis among HIV-1-serodiscordant heterosexual couples from Kenya and Uganda. The HIV-1-seronegative partner in each couple was randomly assigned to one of three study regimens--once-daily tenofovir (TDF), combination tenofovir-emtricitabine (TDF-FTC), or matching placebo--and followed monthly for up to 36 months. At enrollment, the HIV-1-seropositive partners were not eligible for antiretroviral therapy, according to national guidelines. All couples received standard HIV-1 treatment and prevention services.ResultsWe enrolled 4758 couples, of whom 4747 were followed: 1584 randomly assigned to TDF, 1579 to TDF-FTC, and 1584 to placebo. For 62% of the couples followed, the HIV-1-seronegative partner was male. Among HIV-1-seropositive participants, the median CD4 count was 495 cells per cubic millimeter (interquartile range, 375 to 662). A total of 82 HIV-1 infections occurred in seronegative participants during the study, 17 in the TDF group (incidence, 0.65 per 100 person-years), 13 in the TDF-FTC group (incidence, 0.50 per 100 person-years), and 52 in the placebo group (incidence, 1.99 per 100 person-years), indicating a relative reduction of 67% in the incidence of HIV-1 with TDF (95% confidence interval [CI], 44 to 81; P&lt;0.001) and of 75% with TDF-FTC (95% CI, 55 to 87; P&lt;0.001). Protective effects of TDF-FTC and TDF alone against HIV-1 were not significantly different (P=0.23), and both study medications significantly reduced the HIV-1 incidence among both men and women. The rate of serious adverse events was similar across the study groups. Eight participants receiving active treatment were found to have been infected with HIV-1 at baseline, and among these eight, antiretroviral resistance developed in two during the study.ConclusionsOral TDF and TDF-FTC both protect against HIV-1 infection in heterosexual men and women. (Funded by the Bill and Melinda Gates Foundation; Partners PrEP ClinicalTrials.gov number, NCT00557245.)

Polysomal mRNA Association and Gene Expression in <i>Trypanosoma brucei</i>

Background: The contrasting physiological environments of Trypanosoma brucei procyclic (insect vector) and bloodstream (mammalian host) forms necessitates deployment of different molecular processes and, therefore, changes in protein expression. Transcriptional regulation is unusual in T. brucei because the arrangement of genes is polycistronic; however, genes which are transcribed together are subsequently cleaved into separate mRNAs by trans-splicing. Following pre-mRNA processing, the regulation of mature mRNA stability is a tightly controlled cellular process. While many stage-specific transcripts have been identified, previous studies using RNA-seq suggest that changes in overall transcript level do not necessarily reflect the abundance of the corresponding protein. Methods: To better understand the regulation of gene expression in T. brucei, we performed a bioinformatic analysis of RNA-seq on total, sub-polysomal, and polysomal mRNA samples. We further cross-referenced our dataset with a previously published proteomics dataset to identify new protein coding sequences. Results: Our analyses showed that several long non-coding RNAs are more abundant in the sub-polysome samples, which possibly implicates them in regulating cellular differentiation in T. brucei. We also improved the annotation of the T.brucei genome by identifying new putative protein coding transcripts that were confirmed by mass spectrometry data. Conclusions: Several long non-coding RNAs are more abundant in the sub-polysome cellular fractions and might pay a role in the regulation of gene expression. We hope that these data will be of wide general interest, as well as being of specific value to researchers studying gene regulation expression and life stage transitions in T. brucei

Characteristics of HIV-1 Discordant Couples Enrolled in a Trial of HSV-2 Suppression to Reduce HIV-1 Transmission: The Partners Study

Background: The Partners HSV-2/HIV-1 Transmission Study (Partners Study) is a phase III, placebo-controlled trial of daily acyclovir for genital herpes (HSV-2) suppression among HIV-1/HSV-2 co-infected persons to reduce HIV-1 transmission to their HIV-1 susceptible partners, which requires recruitment of HIV-1 serodiscordant heterosexual couples. We describe the baseline characteristics of this cohort. Methods: HIV-1 serodiscordant heterosexual couples, in which the HIV-1 infected partner was HSV-2 seropositive, had a CD4 count ≥250 cells/mcL and was not on antiretroviral therapy, were enrolled at 14 sites in East and Southern Africa. Demographic, behavioral, clinical and laboratory characteristics were assessed. Results: Of the 3408 HIV-1 serodiscordant couples enrolled, 67% of the HIV-1 infected partners were women. Couples had cohabitated for a median of 5 years (range 2–9) with 28% reporting unprotected sex in the month prior to enrollment. Among HIV-1 susceptible participants, 86% of women and 59% of men were HSV-2 seropositive. Other laboratory-diagnosed sexually transmitted infections were uncommon (500 relative to <350, respectively, p<0.001). Conclusions: The Partners Study successfully enrolled a cohort of 3408 heterosexual HIV-1 serodiscordant couples in Africa at high risk for HIV-1 transmission. Follow-up of this cohort will evaluate the efficacy of acyclovir for HSV-2 suppression in preventing HIV-1 transmission and provide insights into biological and behavioral factors determining heterosexual HIV-1 transmission. Trial Registration ClinicalTrials.gov NCT0019451