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Joanne Luoto

Bio: Joanne Luoto is an academic researcher from National Institutes of Health. The author has contributed to research in topics: Spermicide & Population. The author has an hindex of 4, co-authored 5 publications receiving 305 citations.

Papers
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Journal ArticleDOI
01 Jan 2007-AIDS
TL;DR: No association was found between hormonal contraceptive use and HIV acquisition overall, which is reassuring for women needing effective contraception in settings of high HIV prevalence, however, hormonal contraceptive users who were HSV-2 seronegative had an increased risk of HIV acquisition.
Abstract: Combined oral contraceptives (COC) and depot-medroxyprogesterone acetate (DMPA) are among the most widely used family planning methods; their effect on HIV acquisition is not known. The objective was to evaluate the effect of COC and DMPA on HIV acquisition and any modifying effects of other sexually transmitted infections. Methods: This multicenter prospective cohort study enrolled 6109 HIV-uninfected women aged 18-35 years from family planning clinics in Uganda Zimbabwe and Thailand. Participants received HIV testing quarterly for 15-24 months. The risk of HIV acquisition with different contraceptive methods was assessed (excluding Thailand where there were few HIV cases). HIV infection occurred in 213 African participants (2.8/100 woman-years). Use of neither COC [hazard ratio (HR) 0.99; 95% confidence interval (CI) 0.69-1.42] nor DMPA (HR 1.25; 95% CI 0.89-1.78) was associated with risk of HIV acquisition overall including among participants with cervical or vaginal infections. While absolute risk of HIV acquisition was higher among participants who were seropositive for herpes simplex virus 2 (HSV-2) than in those seronegative at enrolment among the HSV-2-seronegative participants both COC (HR 2.85; 95% CI 1.39-5.82) and DMPA (HR 3.97; 95% CI 1.98-8.00) users had an increased risk of HIV acquisition compared with the non-hormonal group. No association was found between hormonal contraceptive use and HIV acquisition overall. This is reassuring for women needing effective contraception in settings of high HIV prevalence. However hormonal contraceptive users who were HSV-2 seronegative had an increased risk of HIV acquisition. Additional research is needed to confirm and explain this finding. (authors)

228 citations

Journal ArticleDOI
TL;DR: The gel with the lowest amount of nonoxynol-9 was less effective than the 2 higher-dose gels and formulation did not significantly affect pregnancy risk.

51 citations

Journal ArticleDOI
TL;DR: All five nonoxynol-9 (N-9) spermicides were considered acceptable by most users and did not appear to influence spermicide use or pregnancy risk.

29 citations

Journal ArticleDOI
TL;DR: Characteristics of participants who failed to complete seven months of planned participation in a trial of spermicide efficacy were explored, finding that failure to complete is a major problem in barrier method trials that seriously compromises the interpretation of results.
Abstract: Background: In most recent large efficacy trials of barrier contraceptive methods, a high proportion of participants withdrew before the intended end of follow-up. The objective of this analysis was to explore characteristics of participants who failed to complete seven months of planned participation in a trial of spermicide efficacy. Methods: Trial participants were expected to use the assigned spermicide for contraception for 7 months or until pregnancy occurred. In bivariable and multivariable analyses, we assessed the associations between failure to complete the trial and 17 pre-specified baseline characteristics. In addition, among women who participated for at least 6 weeks, we evaluated the relationships between failure to complete, various features of their first 6 weeks of experience with the spermicide, and characteristics of the study centers and population. Results: Of the 1514 participants in this analysis, 635 (42%) failed to complete the study for reasons other than pregnancy. Women were significantly less likely to complete if they were younger or unmarried, had intercourse at least 8 times per month, or were enrolled at a university center or at a center that enrolled fewer than 4 participants per month. Noncompliance with study procedures in the first 6 weeks was also associated with subsequent early withdrawal, but

11 citations

Journal Article
01 Jan 2007-AIDS
TL;DR: No association was found between hormonal contraceptive use and HIV acquisition overall, which is reassuring for women needing effective contraception in settings of high HIV prevalence, however, hormonal contraceptive users who were HSV-2 seronegative had an increased risk of HIV acquisition.
Abstract: Background: Combined oral contraceptives (COC) and depot-medroxyprogesterone acetate (DMPA) are among the most widely used family planning methods; their effect on HIV acquisition is not known. Objective: To evaluate the effect of COC and DMPA on HIV acquisition and any modifying effects of other sexually transmitted infections. Methods: This multicenter prospective cohort study enroled 6109 HIV-uninfected women, aged 18-35 years, from family planning clinics in Uganda, Zimbabwe and Thailand. Participants received HIV testing quarterly for 15-24 months. The risk of HIV acquisition with different contraceptive methods was assessed (excluding Thailand, where there were few HIV cases). Results: HIV infection occurred in 213 African participants (2.8/100 woman-years). Use of neither COC [hazard ratio (HR), 0.99; 95% confidence interval (Cl), 0.69-1.42] nor DMPA (HR, 1.25; 95% Cl, 0.89-1.78) was associated with risk of HIV acquisition overall, including among participants with cervical or vaginal infections. While absolute risk of HIV acquisition was higher among participants who were seropositive for herpes simplex virus 2 (HSV-2) than in those seronegative at enrolment, among the HSV-2-seronegative participants, both COC (HR, 2.85; 95% Cl, 1.39-5.82) and DMPA (HR, 3.97; 95% Cl, 1.98-8.00) users had an increased risk of HIV acquisition compared with the non-hormonal group. Conclusions: No association was found between hormonal contraceptive use and HIV acquisition overall. This is reassuring for women needing effective contraception in settings of high HIV prevalence. However, hormonal contraceptive users who were HSV-2 seronegative had an increased risk of HIV acquisition. Additional research is needed to confirm and explain this finding.

1 citations


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Journal ArticleDOI
TL;DR: This review provides an update of previous estimates of first-year probabilities of contraceptive failure for all methods of contraception available in the United States and reflects new research on contraceptive failure both during perfect use and during typical use.

1,441 citations

Journal ArticleDOI
TL;DR: In this article, the authors used Cox proportional hazards regression and marginal structural modeling to assess the effect of contraceptive use on HIV-1 risk and found that women who used hormonal contraception had higher risk of acquiring HIV than those who did not.
Abstract: Summary Background Hormonal contraceptives are used widely but their effects on HIV-1 risk are unclear. We aimed to assess the association between hormonal contraceptive use and risk of HIV-1 acquisition by women and HIV-1 transmission from HIV-1-infected women to their male partners. Methods In this prospective study, we followed up 3790 heterosexual HIV-1-serodiscordant couples participating in two longitudinal studies of HIV-1 incidence in seven African countries. Among injectable and oral hormonal contraceptive users and non-users, we compared rates of HIV-1 acquisition by women and HIV-1 transmission from women to men. The primary outcome measure was HIV-1 seroconversion. We used Cox proportional hazards regression and marginal structural modelling to assess the effect of contraceptive use on HIV-1 risk. Findings Among 1314 couples in which the HIV-1-seronegative partner was female (median follow-up 18·0 [IQR 12·6–24·2] months), rates of HIV-1 acquisition were 6·61 per 100 person-years in women who used hormonal contraception and 3·78 per 100 person-years in those who did not (adjusted hazard ratio 1·98, 95% CI 1·06–3·68, p=0·03). Among 2476 couples in which the HIV-1-seronegative partner was male (median follow-up 18·7 [IQR 12·8–24·2] months), rates of HIV-1 transmission from women to men were 2·61 per 100 person-years in couples in which women used hormonal contraception and 1·51 per 100 person-years in couples in which women did not use hormonal contraception (adjusted hazard ratio 1·97, 95% CI 1·12–3·45, p=0·02). Marginal structural model analyses generated much the same results to the Cox proportional hazards regression. Interpretation Women should be counselled about potentially increased risk of HIV-1 acquisition and transmission with hormonal contraception, especially injectable methods, and about the importance of dual protection with condoms to decrease HIV-1 risk. Non-hormonal or low-dose hormonal contraceptive methods should be considered for women with or at-risk for HIV-1. Funding US National Institutes of Health and the Bill & Melinda Gates Foundation.

446 citations

Journal ArticleDOI
TL;DR: In a meta-analysis of individual participant data, Charles Morrison and colleagues explore the association between hormonal contraception use and risk of HIV infection in sub-Saharan Africa.
Abstract: BACKGROUND: Observational studies of a putative association between hormonal contraception (HC) and HIV acquisition have produced conflicting results. We conducted an individual participant data (IPD) meta-analysis of studies from sub-Saharan Africa to compare the incidence of HIV infection in women using combined oral contraceptives (COCs) or the injectable progestins depot-medroxyprogesterone acetate (DMPA) or norethisterone enanthate (NET-EN) with women not using HC. METHODS AND FINDINGS: Eligible studies measured HC exposure and incident HIV infection prospectively using standardized measures, enrolled women aged 15-49 y, recorded ≥15 incident HIV infections, and measured prespecified covariates. Our primary analysis estimated the adjusted hazard ratio (aHR) using two-stage random effects meta-analysis, controlling for region, marital status, age, number of sex partners, and condom use. We included 18 studies, including 37,124 women (43,613 woman-years) and 1,830 incident HIV infections. Relative to no HC use, the aHR for HIV acquisition was 1.50 (95% CI 1.24-1.83) for DMPA use, 1.24 (95% CI 0.84-1.82) for NET-EN use, and 1.03 (95% CI 0.88-1.20) for COC use. Between-study heterogeneity was mild (I(2) < 50%). DMPA use was associated with increased HIV acquisition compared with COC use (aHR 1.43, 95% CI 1.23-1.67) and NET-EN use (aHR 1.32, 95% CI 1.08-1.61). Effect estimates were attenuated for studies at lower risk of methodological bias (compared with no HC use, aHR for DMPA use 1.22, 95% CI 0.99-1.50; for NET-EN use 0.67, 95% CI 0.47-0.96; and for COC use 0.91, 95% CI 0.73-1.41) compared to those at higher risk of bias (p(interaction) = 0.003). Neither age nor herpes simplex virus type 2 infection status modified the HC-HIV relationship. CONCLUSIONS: This IPD meta-analysis found no evidence that COC or NET-EN use increases women's risk of HIV but adds to the evidence that DMPA may increase HIV risk, underscoring the need for additional safe and effective contraceptive options for women at high HIV risk. A randomized controlled trial would provide more definitive evidence about the effects of hormonal contraception, particularly DMPA, on HIV risk.

360 citations

Journal ArticleDOI
TL;DR: The MRKAd5 HIV- 1 vaccine did not prevent HIV-1 infection or lower viral-load setpoint; however, stopping the trial early probably compromised the ability to draw conclusions.
Abstract: Summary Background The MRKAd5 HIV-1 gag/pol/nef subtype B vaccine was designed to elicit T-cell-mediated immune responses capable of providing complete or partial protection from HIV-1 infection or a decrease in viral load after acquisition. We aim to assess the safety and efficacy of the vaccine in South Africa, where the major circulating clade is subtype C. Methods We did a phase 2b double-blind, randomised test-of-concept study in sexually active HIV-1 seronegative participants at five sites in South Africa. Randomisation was by a computer-generated random number sequence. The vaccine and placebo were given by intramuscular injection on a 0, 1, 6 month schedule. Our coprimary endpoints were a vaccine-induced reduction in HIV-1 acquisition and viral-load setpoint. These endpoints were assessed independently in the modified intention-to-treat (MITT) cohort with two-tailed significance tests stratified by sex. We assessed immunogenicity by interferon-γ ELISPOT in peripheral-blood mononuclear cells. After the lack of efficacy of the MRKAd5 HIV-1 vaccine in the Step study, enrolment and vaccination in our study was halted, treatment allocations were unmasked, and follow-up continued. This study is registered with the South Africa National Health Research Database, number DOH-27-0207-1539, and ClinicalTrials.gov, number NCT00413725. Findings 801 of a scheduled 3000 participants, of whom 360 (45%) were women, were randomly assigned to receive either vaccine or placebo. 445 participants (56%) had adenovirus serotype 5 (Ad5) titres greater than 200, and 129 men (29%) were circumcised. 34 MITT participants in the vaccine group were diagnosed with HIV-1 (incidence rate 4·54 per 100 person-years) and 28 in the placebo group (3·70 per 100 person-years). There was no evidence of vaccine efficacy; the hazard ratio adjusted for sex was 1·25 (95% CI 0·76–2·05). Vaccine efficacy did not differ by Ad5 titre, sex, age, herpes simplex virus type 2 status, or circumcision. The geometric mean viral-load setpoint was 20 483 copies per mL (n=33) in the vaccine group and 34 032 copies per mL (n=28) in the placebo group (p=0·39). The vaccine elicited interferon-γ-secreting T cells that recognised both clade B (89%) and C (77%) antigens. Interpretation The MRKAd5 HIV-1 vaccine did not prevent HIV-1 infection or lower viral-load setpoint; however, stopping our trial early probably compromised our ability to draw conclusions. The high incidence rates noted in South Africa highlight the crucial need for intensified efforts to develop an efficacious vaccine. Funding The US National Institute of Allergy and Infectious Disease and Merck and Co Inc.

355 citations

Journal ArticleDOI
TL;DR: T. vaginalis infection is strongly associated with an increased risk for HIV infection in this general population of African women and may have a substantial impact on preventing HIV acquisition among women.
Abstract: Trichomoniasis vaginalis is the most common nonviral sexually transmitted infection (STI) worldwide with a particularly high prevalence in regions of human immunodeficiency virus (HIV) endemicity. However its impact as a cofactor for HIV acquisition is poorly understood. Samples from 213 women who experienced HIV seroconversion (cases) during a longitudinal study involving 4450 women in Uganda and Zimbabwe were matched with samples from HIV-uninfected women (controls). All samples underwent polymerase chain reaction (PCR) analysis for Trichomonas vaginalis DNA. For cases analyzed samples were from the visit in which HIV seroconversion was detected and the visit preceding detection of seroconversion; for controls one analyzed sample was from the visit matched by follow-up duration to the cases seroconversion visit and the other sample was from the visit immediately preceding the matched visit. The prevalence of T. vaginalis infection before HIV infection was 11.3% in cases and 4.5% in controls (P = .002). In multivariable analysis controlling for hormonal contraception other STIs behavioral and demographic factors the adjusted odds ratio for HIV acquisition was 2.74 (95% confidence interval 1.25-6.00) for T. vaginalis-positive cases. The presence of behavioral risk factors for HIV infection study recruitment from a referral population at high-risk for HIV primary sex partner-associated risk for HIV infection and herpes simplex virus type 2 seropositivity were also predictive of incident HIV infection. T. vaginalis infection is strongly associated with an increased risk for HIV infection in this general population of African women. Given the high prevalence of T. vaginalis infection in HIV-endemic areas T. vaginalis control may have a substantial impact on preventing HIV acquisition among women. (authors)

283 citations