Randomized clinical trials of oral antiretroviral pre-exposure prophylaxis (PrEP) for HIV prevention have widely divergent efficacy estimates, ranging from 0% to 75%. These discrepancies are likely ...due to differences in adherence. To our knowledge, no studies to date have examined the impact of improving adherence through monitoring and/or intervention, which may increase PrEP efficacy, or reported on objective behavioral measures of adherence, which can inform PrEP effectiveness and implementation.
Within the Partners PrEP Study (a randomized placebo-controlled trial of oral tenofovir and emtricitabine/tenofovir among HIV-uninfected members of serodiscordant couples in Kenya and Uganda), we collected objective measures of PrEP adherence using unannounced home-based pill counts and electronic pill bottle monitoring. Participants received individual and couples-based adherence counseling at PrEP initiation and throughout the study; counseling was intensified if unannounced pill count adherence fell to <80%. Participants were followed monthly to provide study medication, adherence counseling, and HIV testing. A total of 1,147 HIV-uninfected participants were enrolled: 53% were male, median age was 34 years, and median partnership duration was 8.5 years. Fourteen HIV infections occurred among adherence study participants--all of whom were assigned to placebo (PrEP efficacy = 100%, 95% confidence interval 83.7%-100%, p<0.001). Median adherence was 99.1% (interquartile range IQR 96.9%-100%) by unannounced pill counts and 97.2% (90.6%-100%) by electronic monitoring over 807 person-years. Report of no sex or sex with another person besides the study partner, younger age, and heavy alcohol use were associated with <80% adherence; the first 6 months of PrEP use and polygamous marriage were associated with >80% adherence. Study limitations include potential shortcomings of the adherence measures and use of a convenience sample within the substudy cohort.
The high PrEP adherence achieved in the setting of active adherence monitoring and counseling support was associated with a high degree of protection from HIV acquisition by the HIV-uninfected partner in heterosexual serodiscordant couples. Low PrEP adherence was associated with sexual behavior, alcohol use, younger age, and length of PrEP use. Please see later in the article for the Editors' Summary.
Summary Background Antiretroviral pre-exposure prophylaxis (PrEP), with daily oral tenofovir disoproxil fumarate or tenofovir disoproxil fumarate in combination with emtricitabine, has been shown to ...be efficacious for HIV-1 prevention. Although the use of more than one antiretroviral agent is essential for effective HIV-1 treatment, more than one agent might not be required for effective prophylaxis. We assessed the efficacy of single-agent tenofovir disoproxil fumarate relative to combination emtricitabine plus tenofovir disoproxil fumarate as PrEP. Methods We did a randomised, double-blind, placebo-controlled three-group phase 3 trial of daily oral tenofovir disoproxil fumarate and emtricitabine plus tenofovir disoproxil fumarate PrEP in HIV-1 uninfected individuals in heterosexual HIV-1 serodiscordant couples from Kenya and Uganda. After an interim review, the trial's placebo group was discontinued and thereafter the active groups were continued, and participants initially randomly assigned to placebo were offered rerandomisation in a 1:1 ratio to tenofovir disoproxil fumarate or emtricitabine plus tenofovir disoproxil fumarate as PrEP. The primary endpoints were HIV-1 seroconversion and safety. This trial is registered with ClinicalTrials.gov , number NCT00557245. Findings 4410 (99·6%) of 4427 couples received tenofovir disoproxil fumarate or emtricitabine plus tenofovir disoproxil fumarate and were followed up for HIV-1 acquisition. Of 52 incident HIV-1 infections, 31 occurred in individuals assigned tenofovir disoproxil fumarate (incidence 0·71 cases per 100 person-years) and 21 were in those assigned emtricitabine plus tenofovir disoproxil fumarate (0·48 cases per 100 person-years); HIV-1 incidence in the placebo group until discontinuation was two cases per 100 person-years. HIV-1 prevention efficacy with emtricitabine plus tenofovir disoproxil fumarate was not significantly different from that of tenofovir disoproxil fumarate alone (hazard ratio HR 0·67, 95% CI 0·39–1·17; p=0·16). Detection of tenofovir in plasma samples, compared with no detection and as measured in seroconverters and a subset of non-seroconverters, was associated with an 85% relative risk reduction in HIV-1 acquisition for the tenofovir disoproxil fumarate group (HR 0·15, 95% CI 0·06–0·37; p<0·0001) and 93% for the emtricitabine plus tenofovir disoproxil fumarate group (0·07, 0·02–0·23; p<0·0001). No significant differences were noted in the frequency of deaths, serious adverse events, or serum creatinine and phosphorus abnormalities between the two groups. Interpretation These results do not rule out the potential for a slight difference in HIV-1 protection with tenofovir disoproxil fumarate compared with emtricitabine plus tenofovir disoproxil fumarate, but show that once-daily oral tenofovir disoproxil fumarate or emtricitabine plus tenofovir disoproxil fumarate regimens both provide high protection against HIV-1 acquisition in heterosexual men and women. Funding Bill & Melinda Gates Foundation and US National Institutes of Health.
Stable heterosexual HIV-1 serodiscordant couples in Africa have high HIV-1 transmission rates and are a critical population for evaluation of new HIV-1 prevention strategies. The Partners PrEP Study ...is a randomized, double-blind, placebo-controlled trial of tenofovir and emtricitabine-tenofovir pre-exposure prophylaxis to decrease HIV-1 acquisition within heterosexual HIV-1 serodiscordant couples. We describe the trial design and characteristics of the study cohort.
HIV-1 serodiscordant couples, in which the HIV-1 infected partner did not meet national guidelines for initiation of antiretroviral therapy, were enrolled at 9 research sites in Kenya and Uganda. The HIV-1 susceptible partner was randomized to daily oral tenofovir, emtricitabine-tenofovir, or matching placebo with monthly follow-up for 24-36 months.
From July 2008 to November 2010, 7920 HIV-1 serodiscordant couples were screened and 4758 enrolled. For 62% (2966/4758) of enrolled couples, the HIV-1 susceptible partner was male. Median age was 33 years for HIV-1 susceptible and HIV-1 infected partners IQR (28-40) and (26-39) respectively. Most couples (98%) were married, with a median duration of partnership of 7.0 years (IQR 3.0-14.0) and recent knowledge of their serodiscordant status median 0.4 years (IQR 0.1-2.0). During the month prior to enrollment, couples reported a median of 4 sex acts (IQR 2-8); 27% reported unprotected sex and 14% of male and 1% of female HIV-1 susceptible partners reported sex with outside partners. Among HIV-1 infected partners, the median plasma HIV-1 level was 3.94 log(10) copies/mL (IQR 3.31-4.53) and median CD4 count was 496 cells/µL (IQR 375-662); the majority (64%) had WHO stage 1 HIV-1 disease.
Couples at high risk of HIV-1 transmission were rapidly recruited into the Partners PrEP Study, the largest efficacy trial of oral PrEP. (ClinicalTrials.gov NCT00557245).
We examined the real-world effectiveness of ART as an HIV prevention tool among HIV serodiscordant couples in a programmatic setting in a low-income country.
We enrolled individuals from HIV ...serodiscordant couples aged ≥18 years of age in Jinja, Uganda from June 2009 - June 2011. In one group of couples the HIV positive partner was receiving ART as they met clinical eligibility criteria (a CD4 cell count ≤250 cells/ μL or WHO Stage III/IV disease). In the second group the infected partner was not yet ART-eligible. We measured HIV incidence by testing the uninfected partner every three months. We conducted genetic linkage studies to determine the source of new infections in seroconverting participants.
A total of 586 couples were enrolled of which 249 (42%) of the HIV positive participants were receiving ART at enrollment, and an additional 99 (17%) initiated ART during the study. The median duration of follow-up was 1.5 years. We found 9 new infections among partners of participants who had been receiving ART for at least three months and 8 new infections in partners of participants who had not received ART or received it for less than three months, for incidence rates of 2.09 per 100 person-years (PYRs) and 2.30 per 100 PYRs, respectively. The incidence rate ratio for ART-use was 0.91 (95% confidence interval 0.31-2.70; p=0.999). The hazard ratio for HIV seroconversion associated with ART-use by the positive partner was 1.07 (95% CI 0.41-2.80). A total of 5/7 (71%) of the transmissions on ART and 6/7 (86%) of those not on ART were genetically linked.
Overall HIV incidence was low in comparison to previous studies of serodiscordant couples. However, ART-use was not associated with a reduced risk of HIV transmission in this study.
During an HIV-1 prevention clinical trial in East Africa, we observed 16 cases of primary HIV-1 infection in women coincident with pregnancy or breastfeeding. Nine of eleven pregnant women initiated ...rapid combination antiretroviral therapy (ART), despite having CD4 counts exceeding national criteria for ART initiation; breastfeeding women initiated ART or replacement feeding. Rapid ART initiation during primary HIV-1 infection during pregnancy and breastfeeding is feasible in this setting.
The choice of infant feeding method is important for HIV-positive mothers in order to optimise the chance of survival of their infants and to minimise the risk of HIV transmission. The aim of this ...study was to investigate feeding practices, including breastfeeding, in the context of PMTCT for infants and children under two years of age born to HIV-positive mothers in Uganda.
In collaboration with The Aids Support Organisation Mbale, we conducted a cross-sectional survey involving 235 HIV-positive mothers in Uganda. Infant feeding practices, reasons for stopping breastfeeding, and breast health problems were studied. Breastfeeding duration was analysed using the Kaplan-Meier method based on retrospective recall.
Breastfeeding was initiated by most of the mothers, but 20 of them (8.5%) opted exclusively for replacement feeding. Pre-lacteal feeding was given to 150 (64%) infants and 65 (28%) practised exclusive breastfeeding during the first three days. One-fifth of the infants less than 6 months old were exclusively breastfed, the majority being complementary fed including breast milk. The median duration of breastfeeding was 12 months (95% confidence interval CI 11.5 to 12.5). Adjusted Cox regression analysis indicated that a mother's education, socio-economic status, participation in the PMTCT-program and her positive attitude to breastfeeding exclusively, were all associated with a reduction in breastfeeding duration. Median duration was 3 months (95% CI 0-10.2) among the most educated mothers, and 18 months (95% CI 15.0-21.0) among uneducated mothers. Participation in the PMTCT program and being socio-economically better-off were also associated with earlier cessation of breastfeeding (9 months 95% CI 7.2-10.8 vs. 14 months 95% CI 10.8-17.2 and 8 months 95% CI 5.9-10.1 vs. 17 months 95% CI 15.2-18.8, respectively). The main reasons for stopping breastfeeding were reported as: advice from health workers, maternal illness, and the HIV-positive status of the mother.
Exclusive breastfeeding was uncommon. Exclusive replacement feeding was practised by few HIV-positive mothers. Well-educated mothers, mothers who were socio-economically better-off and PMTCT-attendees had the shortest durations of breastfeeding. Further efforts are needed to optimise infant feeding counselling and to increase the feasibility of the recommendations.
IMPORTANCE: Antiretroviral preexposure prophylaxis (PrEP), using tenofovir disoproxil fumarate (TDF) and combination emtricitabine/tenofovir disoproxil fumarate (FTC+TDF), is efficacious for ...prevention of human immunodeficiency virus (HIV) acquisition. PrEP could reduce periconception HIV risk, but the effect on pregnancy outcomes is not well defined. OBJECTIVE: To assess pregnancy incidence and outcomes among women using PrEP during the periconception period. DESIGN, SETTING, AND PARTICIPANTS: Randomized trial among 1785 HIV-serodiscordant heterosexual couples (the Partners PrEP Study) in which the female partner was HIV uninfected that demonstrated that PrEP was efficacious for HIV prevention, conducted between July 2008 and June 2013 at 9 sites in Kenya and Uganda. INTERVENTIONS: Daily oral TDF (n = 598), combination FTC+TDF (n = 566), or placebo (n = 621) through July 2011, when PrEP demonstrated efficacy for HIV prevention. Thereafter, participants continued receiving active PrEP without placebo. Pregnancy testing occurred monthly and study medication was discontinued when pregnancy was detected. MAIN OUTCOMES AND MEASURES: Pregnancy incidence, birth outcomes (live births, pregnancy loss, preterm birth, congenital anomalies), and infant growth. RESULTS: A total of 431 pregnancies occurred. Pregnancy incidence was 10.0 per 100 person-years among women assigned placebo, 11.9 among those assigned TDF (incidence difference, 1.9; 95% CI, −1.1 to 4.9 P = .22 vs placebo), and 8.8 among those assigned FTC+TDF (incidence difference, −1.3; 95% CI, −4.1 to 1.5 P = .39 vs placebo). Before discontinuation of the placebo treatment group in July 2011, the occurrence of pregnancy loss (96 of 288 pregnancies) was 42.5% for women receiving FTC+TDF compared with 32.3% for those receiving placebo (difference for FTC+TDF vs placebo, 10.2%; 95% CI, −5.3% to 25.7%; P = .16) and was 27.7% for those receiving TDF alone (difference vs placebo, −4.6%; 95% CI, −18.1% to 8.9%; P = .46). After July 2011, the frequency of pregnancy loss (52 of 143 pregnancies) was 37.5% for FTC+TDF and 36.7% for TDF alone (difference, 0.8%; 95% CI, −16.8% to 18.5%; P = .92). Occurrence of preterm birth, congenital anomalies, and growth throughout the first year of life did not differ significantly for infants born to women who received PrEP vs placebo. CONCLUSIONS AND RELEVANCE: Among HIV-serodiscordant heterosexual African couples, differences in pregnancy incidence, birth outcomes, and infant growth were not statistically different for women receiving PrEP with TDF alone or combination FTC+TDF compared with placebo at conception. Given that PrEP was discontinued when pregnancy was detected and that CIs for the birth outcomes were wide, definitive statements about the safety of PrEP in the periconception period cannot be made. These results should be discussed with HIV-uninfected women receiving PrEP who are considering becoming pregnant. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00557245
Background. Preexposure prophylaxis (PrEP) with emtricitabine plus tenofovir disoproxil fumarate (FTC/TDF) or TDF alone reduces the risk of human immunodeficiency virus (HIV) acquisition. ...Understanding the risk of antiretroviral resistance selected by PrEP during breakthrough infections is important because of the risk of treatment failure during subsequent antiretroviral use. Methods. Within the largest randomized trial of FTC/TDF versus TDF as PrEP, plasma samples were tested for HIV with resistance mutations associated with FTC (K65R and M184IV) and TDF (K65R and K70E), using 454 sequencing. Results. Of 121 HIV seroconverters, 25 received FTC/TDF, 38 received TDF, and 58 received placebo. Plasma drug levels in 26 individuals indicated PrEP use during or after HIV acquisition, of which 5 had virus with resistance mutations associated with their PrEP regimen. Among those with PrEP drug detected during infection, resistance was more frequent in the FTC/TDF arm (4 of 7 57%), compared with the TDF arm (1 of 19 5.3%; P = .01), owing to the FTC-associated mutation M184IV. Of these cases, 3 had unrecognized acute infection at PrEP randomization, and 2 were HIV negative at enrollment. Conclusions. These results suggest that resistance selected by PrEP is rare but can occur both with PrEP initiation during acute seronegative HIV infection and in PrEP breakthrough infections and that FTC is associated with a greater frequency of resistance mutations than TDF.
Abstract
New tools are needed to support pre-exposure prophylaxis (PrEP) adherence for human immunodeficiency virus (HIV) prevention, including those that enable real-time feedback. In a large, ...completed PrEP trial, adequate urine tenofovir levels measured using a novel immunoassay predicted HIV protection and showed good sensitivity and specificity for detectable plasma tenofovir.
Community-drug distribution point is a care model for stable patients in the community designed to make ART delivery more efficient for the health system and provide appropriate support to encourage ...long-term retention of patients. We examined program retention among ART program participants in rural Uganda, which has used a community-based distribution model of ART delivery since 2004.
We analyzed data of all patients >18 years who initiated ART in Jinja, Ugandan site of The AIDS Support Organization between January 1, 2004 and July 31, 2009. Participants attended clinic or outreach visits every 2-3 months and had CD4 cell counts measured every 6 months. Retention to care was defined as any patient with at least one visit in the 6 months before June 1, 2013. We then identified participants with at least one visit in the 6 months before June 1, 2013 and examined associations with mortality and lost-to-follow-up (LTFU). Participants with >4 years of follow up during August, 2012 to May, 2013 had viral load conducted, since no routine viral load testing was available.
A total of 3345 participants began ART during 2004-2009. The median time on ART in June 2013 was 5.69 years. A total of 1335 (40 %) were residents of Jinja district and 2005 (60 %) resided in outlying districts. Of these, 2322 (69 %) were retained in care, 577 (17 %) died, 161 (5 %) transferred out and 285 (9 %) were LTFU. Factors associated with mortality or LTFU included male gender, Adjusted Hazard Ratio (AHR) = 1.56; 95 % CI 1.28-1.9, CD4 cell count <50 cells/μL (AHR = 4.09; 95 % CI 3.13-5.36) or 50-199 cells/μL (AHR = 1.86; 95 % CI 1.46-2.37); ART initiation and WHO stages 3 (AHR = 1.35; 95 % CI 1.1-1.66) or 4 (AHR = 1.74; 95 % CI 1.23-2.45). Residence outside of Jinja district was not associated with mortality/LTFU (p value = 0.562). Of 870 participants who had VL tests, 756 (87 %) had VLs <50 copies/mL.
Community-based ART distribution systems can effectively mitigate the barriers to program retention and result in good rates of virologic suppression.
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