30 research outputs found

    Towards standardized definitions for monitoring the continuum of HIV care in Europe

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    International audienceThe continuum of HIV care is a simple conceptual framework for monitoring HIV programmes, comprising a series of stages that people living with HIV (PLHIV) pass through to access antiretroviral treatment (ART) and achieve viral suppression [1,2]. Individual benefits of suppression include reduced risk of morbidity and mortality. At the population level, viral suppression reduces the risk of onward transmission and enables epidemic containment [3]. Transmission risk may be further reduced by lowering the number of undiagnosed PLHIV [4,5]. Complete continua are, therefore, constructed beginning with the total number of PLHIV in a given population and ending with the number virally suppressed. Intervening stages have included the numbers diagnosed, linked to HIV care, retained in care, eligible for ART, on ART and adhering to ART. Although people can move between stages, the continuum is typically conceptualized as a ‘snapshot’ at one time-point

    Impact of DREAMS interventions on experiences of violence among adolescent girls and young women: Findings from population-based cohort studies in Kenya and South Africa

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    DREAMS aims to reduce HIV incidence among adolescent girls and young women (AGYW) by tackling drivers of HIV risk including gender-based violence. We evaluate the impact of DREAMS on recent experiences of violence perpetuated by men against AGYW. AGYW cohorts were randomly selected from demographic platforms in South Africa (rural KwaZulu-Natal) and Kenya (Nairobi informal settlements and rural Gem sub-county). AGYW aged 13-22 years were enrolled in 2017 (Nairobi, KwaZulu-Natal) or 2018 (Gem), with annual follow-up to 2019. We described proportions of AGYW who self-reported experiences of violence perpetrated by males in the 12 months preceding the interview, overall and by form (physical, sexual, emotional). We investigated associations with DREAMS (invitation to participate during 2017-2018) through multivariable propensity score-adjusted logistic regression and estimated the causal effect of DREAMS on experiences of violence, under counter-factual scenarios in which all versus no AGYW were DREAMS beneficiaries. Among 852, 1018 and 1712 AGYW followed-up in 2019 in Nairobi, Gem and KZN, respectively, proportions reporting any violence in 2019 were higher in Nairobi (29%) than Gem (18%) and KwaZulu-Natal (19%). By sub-type, emotional and physical violence were more frequently reported than sexual violence. We found no evidence of an impact attributable to DREAMS on overall levels of violence, in any setting. Nor was there evidence of impact on sub-types of violence, with one exception: an increase in physical violence in Nairobi if all, versus no, AGYW were DREAMS beneficiaries (16% vs 11%; +5% difference [95% CI: +0.2%, +10.0%]). Experiences of gender-based violence were common among AGYW, especially in urban settings, and DREAMS had no measurable impact on reducing violence within three years of implementation. Violence prevention programming that reaches more men and the broader community, sustained for longer periods, may yield greater gains in violence reduction than AGYW-focused programming. Additionally, more investment in implementation research is needed to bridge trial-based study findings from efficacy to population-level effectiveness

    Using Vignettes in Qualitative Research to Explore Barriers and Facilitating Factors to the Uptake of Prevention of Mother-to-Child Transmission Services in Rural Tanzania: A Critical Analysis.

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    Vignettes are short stories about a hypothetical person, traditionally used within research (quantitative or qualitative) on sensitive topics in the developed world. Studies using vignettes in the developing world are emerging, but with no critical examination of their usefulness in such settings. We describe the development and application of vignettes to a qualitative investigation of barriers to uptake of prevention of mother-to-child transmission (PMTCT) HIV services in rural Tanzania in 2012, and critique the successes and challenges of using the technique in this setting. Participatory Learning and Action (PLA) group activities (3 male; 3 female groups from Kisesa, north-west Tanzania) were used to develop a vignette representing realistic experiences of an HIV-infected pregnant woman in the community. The vignette was discussed during in-depth interviews with 16 HIV-positive women, 3 partners/relatives, and 5 HIV-negative women who had given birth recently. A critical analysis was applied to assess the development, implementation and usefulness of the vignette. The majority of in-depth interviewees understood the concept of the vignette and felt the story was realistic, although the story or questions needed repeating in some cases. In-depth interviewers generally applied the vignette as intended, though occasionally were unsure whether to steer the conversation back to the vignette character when participants segued into personal experiences. Interviewees were occasionally confused by questions and responded with what the character should do rather than would do; also confusing fieldworkers and presenting difficulties for researchers in interpretation. Use of the vignette achieved the main objectives, putting most participants at ease and generating data on barriers to PMTCT service uptake. Participants' responses to the vignette often reflected their own experience (revealed later in the interviews). Participatory group research is an effective method for developing vignettes. A vignette was incorporated into qualitative interview discussion guides and used successfully in rural Africa to draw out barriers to PMTCT service use; vignettes may also be valuable in HIV, health service use and drug adherence research in this setting. Application of this technique can prove challenging for fieldworkers, so thorough training should be provided prior to its use

    Viral genetic variation accounts for a third of variability in HIV-1 set-point viral load in Europe

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    HIV-1 set-point viral load-the approximately stable value of viraemia in the first years of chronic infection-is a strong predictor of clinical outcome and is highly variable across infected individuals. To better understand HIV-1 pathogenesis and the evolution of the viral population, we must quantify the heritability of set-point viral load, which is the fraction of variation in this phenotype attributable to viral genetic variation. However, current estimates of heritability vary widely, from 6% to 59%. Here we used a dataset of 2,028 seroconverters infected between 1985 and 2013 from 5 European countries (Belgium, Switzerland, France, the Netherlands and the United Kingdom) and estimated the heritability of set-point viral load at 31% (CI 15%-43%). Specifically, heritability was measured using models of character evolution describing how viral load evolves on the phylogeny of whole-genome viral sequences. In contrast to previous studies, (i) we measured viral loads using standardized assays on a sample collected in a strict time window of 6 to 24 months after infection, from which the viral genome was also sequenced; (ii) we compared 2 models of character evolution, the classical "Brownian motion" model and another model ("Ornstein-Uhlenbeck") that includes stabilising selection on viral load; (iii) we controlled for covariates, including age and sex, which may inflate estimates of heritability; and (iv) we developed a goodness of fit test based on the correlation of viral loads in cherries of the phylogenetic tree, showing that both models of character evolution fit the data well. An overall heritability of 31% (CI 15%-43%) is consistent with other studies based on regression of viral load in donor-recipient pairs. Thus, about a third of variation in HIV-1 virulence is attributable to viral genetic variation.Peer reviewe

    Easy and accurate reconstruction of whole HIV genomes from short-read sequence data with shiver

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    Studying the evolution of viruses and their molecular epidemiology relies on accurate viral sequence data, so that small differences between similar viruses can be meaningfully interpreted. Despite its higher throughput and more detailed minority variant data, next-generation sequencing has yet to be widely adopted for HIV. The difficulty of accurately reconstructing the consensus sequence of a quasispecies from reads (short fragments of DNA) in the presence of large between-and within-host diversity, including frequent indels, may have presented a barrier. In particular, mapping (aligning) reads to a reference sequence leads to biased loss of information; this bias can distort epidemiological and evolutionary conclusions. De novo assembly avoids this bias by aligning the reads to themselves, producing a set of sequences called contigs. However contigs provide only a partial summary of the reads, misassembly may result in their having an incorrect structure, and no information is available at parts of the genome where contigs could not be assembled. To address these problems we developed the tool shiver to pre-process reads for quality and contamination, then map them to a reference tailored to the sample using corrected contigs supplemented with the user's choice of existing reference sequences. Run with two commands per sample, it can easily be used for large heterogeneous data sets. We used shiver to reconstruct the consensus sequence and minority variant information from paired-end short-read whole-genome data produced with the Illumina platform, for sixty-five existing publicly available samples and fifty new samples. We show the systematic superiority of mapping to shiver's constructed reference compared with mapping the same reads to the closest of 3,249 real references: median values of 13 bases called differently and more accurately, 0 bases called differently and less accurately, and 205 bases of missing sequence recovered. We also successfully applied shiver to whole-genome samples of Hepatitis C Virus and Respiratory Syncytial Virus. shiver is publicly available from https://github.com/ChrisHIV/shiver.Peer reviewe

    Association between invitation to DREAMS and emotional violence among AGYW in uMkhanyakude using conventional logistic regression, 13–22 year-olds

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    Table showing the association between invitation to DREAMS and emotional violence among adolescent girls and young women in uMkhanyakude using conventional logistic regression, 13–22 year-olds

    Association between invitation to DREAMS and any experience of violence among AGYW in Gem using conventional logistic regression

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    Table showing the association between invitation to DREAMS and any experience of violence among adolescent girls and young women in Gem using conventional logistic regression

    Proportions of AGYW retained in the study vs lost to follow up by 2019, by AGYW characteristics in Nairobi

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    Table showing the proportions of adolescent girls and young women retained in the study vs lost to follow up by 2019, by adolescent girls and young women characteristics in Nairobi

    Association between invitation to DREAMS and sexual violence among AGYW in Gem using conventional logistic regression, 13–22 year-olds

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    Table showing the association between invitation to DREAMS and sexual violence among adolescent girls and young women in Gem using conventional logistic regression, 13–22 year-olds

    Characteristics of DREAMS beneficiaries and non-beneficiaries at time of cohort enrolment by invitation to DREAMS in Nairobi, Gem and uMkhanyakude

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    Table showing the characteristics of DREAMS beneficiaries and non-beneficiaries at time of cohort enrolment by invitation to DREAMS in Nairobi and Gem in Kenya, and uMkhanyakude in South Africa
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