External infections contribute minimally to HIV incidence among HIV sero-discordant couples in sub-Saharan Africa.
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ABSTRACT: Objective
Recent randomised clinical trials among stable HIV sero-discordant couples (SDCs) in sub-Saharan Africa (SSA) have reported that about 20-30% of new HIV infections are acquired from external sexual partners, rather than transmitted from the infected to the uninfected partner within the couple. The aim of this study is to examine whether, and to what extent, these findings are generalisable to SDCs in the wider population in SSA.Methods
A mathematical model was constructed to calculate the fraction of new HIV-1 infections among SDCs that are due to sources external to the couple. The model was parameterised using empirical and population-based data for 20 countries in SSA. Uncertainty and sensitivity analyses were also conducted.Results
The contribution of external infections among SDCs was generally modest, but it varied widely across SSA. In low HIV prevalence countries (? 3.0%), it ranged from 0.6-2.9%. In intermediate prevalence countries (3.0-18.0%), it ranged from 4.9-11.7%. In Swaziland and Lesotho, the world's most-intense epidemics, sizable levels of 27.9% and 27.3% were found, respectively.Conclusions
In most countries in SSA, nearly all HIV acquisitions by the uninfected partners in SDCs appear to be due to transmissions from the HIV infected partners in the SDCs. The contribution of externally acquired infections varies with HIV population prevalence, but rarely exceeds 10% in the majority of countries. Only in hyperendemic HIV epidemics the contribution of external infections is substantial and may reach the levels reported in recent randomised clinical trials involving SDCs.
SUBMITTER: Chemaitelly H
PROVIDER: S-EPMC3595149 | biostudies-literature | 2013 Mar
REPOSITORIES: biostudies-literature
Publications
External infections contribute minimally to HIV incidence among HIV sero-discordant couples in sub-Saharan Africa.
Chemaitelly Hiam H Abu-Raddad Laith J LJ
Sexually transmitted infections 20120828 2
<h4>Objective</h4>Recent randomised clinical trials among stable HIV sero-discordant couples (SDCs) in sub-Saharan Africa (SSA) have reported that about 20-30% of new HIV infections are acquired from external sexual partners, rather than transmitted from the infected to the uninfected partner within the couple. The aim of this study is to examine whether, and to what extent, these findings are generalisable to SDCs in the wider population in SSA.<h4>Methods</h4>A mathematical model was construct ...[more]
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Project description:Objective was to examine the temporal variation of HIV sero-discordancy in select representative countries (Kenya, Lesotho, Mali, Niger, Tanzania, and Zimbabwe) in sub-Saharan Africa at different HIV epidemic scales. A sero-discordant couple is defined as a stable couple (SC) in which one partner is HIV-positive while the other is HIV-negative.A deterministic compartmental mathematical model was constructed to describe HIV transmission dynamics. The model was pair-based, that is explicitly modeling formation of SCs and infection dynamics in both SCs and in single individuals. The model accommodated for different forms of infection statuses in SCs. Using population-based nationally-representative epidemiologic and demographic input data, historical (1980-2014) and future (2015-2030) trends of sero-discordancy and other demographic and epidemiologic indicators were projected throughout HIV epidemic phases.As the epidemics emerged, about 90% of SCs affected by HIV were sero-discordant. This proportion declined to 45%-88% at epidemic peak and stabilized as the epidemics started their natural decline. The largest reductions in sero-discordancy were in high HIV-prevalence countries. As the epidemics further declined with antiretroviral therapy (ART) scale-up, the proportion of sero-discordant couples among HIV-affected couples was projected to increase to 70%-92% by 2030. The proportion of sero-discordant couples among all SCs increased as the epidemics emerged and evolved, then peaked at 2%-20% as the epidemics peaked, and then declined as the epidemics declined to reach 0.3%-16% by 2030.Sero-discordancy patterns varied with the evolution of the epidemics, and were affected by both epidemic phase and scale. The largest variations were found in high HIV-prevalence countries. The fraction of stable couples that are sero-discordant, as opposed to being sero-concordant positive, was projected to increase with ART scale-up and further HIV incidence decline over the coming two decades. These findings inform strategic planning and resource allocation for interventions among sero-discordant couples.
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Project description:Sub-Saharan Africa represents 69% of the total number of individuals living with HIV infection worldwide and 72% of AIDS deaths globally. Pulmonary infection is a common and frequently fatal complication, though little is known regarding the lower airway microbiome composition of this population. Our objectives were to characterize the lower airway microbiome of Ugandan HIV-infected patients with pneumonia, to determine relationships with demographic, clinical, immunological, and microbiological variables and to compare the composition and predicted metagenome of these communities to a comparable cohort of patients in the US (San Francisco). Bronchoalveolar lavage samples from a cohort of 60 Ugandan HIV-infected patients with acute pneumonia were collected. Amplified 16S ribosomal RNA was profiled and aforementioned relationships examined. Ugandan airway microbiome composition and predicted metagenomic function were compared to US HIV-infected pneumonia patients. Among the most common bacterial pulmonary pathogens, Pseudomonas aeruginosa was most prevalent in the Ugandan cohort. Patients with a richer and more diverse airway microbiome exhibited lower bacterial burden, enrichment of members of the Lachnospiraceae and sulfur-reducing bacteria and reduced expression of TNF-alpha and matrix metalloproteinase-9. Compared to San Franciscan patients, Ugandan airway microbiome were significantly richer, and compositionally distinct with predicted metagenomes that encoded a multitude of distinct pathogenic pathways e.g secretion systems. Ugandan pneumonia-associated airway microbiome is compositionally and functionally distinct from those detected in comparable patients in developed countries, a feature which may contribute to adverse outcomes in this population. Please note that the data from the comparable cohort of patients in the USUS data was published as supplemental material of PMID: 22760045 but not submitted to GEO The 'patient_info.txt' contains 12 clinical, 7 immunological and 3 microbiological variables for each patient.
2014-02-20 | GSE52791 | GEO
Project description:INTRODUCTION:More new HIV-1 infections occur within stable HIV-1-discordant couples than in any other group in Africa, and sexually transmitted infections (STIs) may increase transmission risk among discordant couples, accounting for a large proportion of new HIV-1 infections. Understanding correlates of STIs among discordant couples will aid in optimizing interventions to prevent HIV-1 transmission in these couples. METHODS:HIV-1-discordant couples in which HIV-1-infected partners were HSV-2-seropositive were tested for syphilis, chlamydia, gonorrhea, and trichomoniasis, and HIV-1-uninfected partners were tested for HSV-2. We assessed sociodemographic, behavioral, and biological correlates of a current STI. RESULTS:Of 416 couples enrolled, 16% were affected by a treatable STI, and among these both partners were infected in 17% of couples. A treatable STI was found in 46 (11%) females and 30 (7%) males. The most prevalent infections were trichomoniasis (5.9%) and syphilis (2.6%). Participants were 5.9-fold more likely to have an STI if their partner had an STI (P<0.01), and STIs were more common among those reporting any unprotected sex (OR = 2.43; P<0.01) and those with low education (OR = 3.00; P<0.01). Among HIV-1-uninfected participants with an HSV-2-seropositive partner, females were significantly more likely to be HSV-2-seropositive than males (78% versus 50%, P<0.01). CONCLUSIONS:Treatable STIs were common among HIV-1-discordant couples and the majority of couples affected by an STI were discordant for the STI, with relatively high HSV-2 discordance. Awareness of STI correlates and treatment of both partners may reduce HIV-1 transmission. TRIAL REGISTRATION:ClinicalTrials.gov NCT00194519.
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Project description:IntroductionCouple HIV testing and counselling (CHTC) is associated with measurable benefits for HIV prevention and treatment. However, the uptake remains limited in much of sub-Saharan Africa, despite an expanded range of strategies designed to promote access.MethodsFollowing PRIMSA guidelines, we conducted a systematic review to characterize CHTC uptake strategies. Five databases were searched. Full-text articles were included if they were: conducted in sub-Saharan Africa during the study period (1980-2019), targeted heterosexual couples, reported at least one strategy to promote CHTC and provided a quantifiable measure of CHTC uptake. After the initial and full-text screening, key features of the studies were abstracted and synthesized.ResultsOf the 6188 unique records found in our search, 365 underwent full-text review with 29 distinct studies included and synthesized. Most studies recruited couples through antenatal care (n = 11) or community venues (n = 8) and used provider-based HIV testing (n = 25). The primary demand creation strategies included home-based CHTC (n = 7); integration of CHTC into clinical settings (n = 4); distribution of HIV self-testing kits (n = 4); verbal or written invitations (n = 4); community recruiters (n = 3); partner tracing (n = 2); relationship counselling (n = 2); financial incentives (n = 1); group education with CHTC coupons (n = 1); and HIV testing at other community venues (n = 1). CHTC uptake ranged from negligible to nearly universal.DiscussionWe thematically categorized a diverse range of strategies with varying levels of intensity and resources used across sub-Saharan Africa to promote CHTC. Offering CHTC within couples' homes was the most common approach, followed by the integration of CHTC into clinical settings. Due to heterogeneity in study characteristics, we were unable to compare the effectiveness across studies, but several trends were observed, including the high prevalence of CHTC promotion strategies in antenatal settings and the promising effects of home-based CHTC, distribution of HIV self-tests and integration of CHTC into routine health services. Since 2019, an updated literature search found that combining partner notification and secondary distribution of HIV self-test kits may be an additionally effective CHTC strategy.ConclusionsThere are many effective, feasible and scalable approaches to promote CHTC that should be considered by national programmes according to local needs, cultural context and available resources.
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2014-02-20 | E-GEOD-52791 | biostudies-arrayexpress
Project description:BACKGROUND:Antiretroviral drugs have been shown to reduce risk of mother-to-child transmission of human immunodeficiency virus (HIV) and are also widely used for post-exposure prophylaxis for parenteral and sexual exposures. Sexual transmission may be lower in couples in which one partner is infected with HIV and the other is not and the infected partner is on antiretroviral therapy (ART). OBJECTIVES:To determine if ART use in an HIV-infected member of an HIV-discordant couple is associated with lower risk of HIV transmission to the uninfected partner compared to untreated discordant couples. SEARCH METHODS:We used standard Cochrane methods to search electronic databases and conference proceedings with relevant search terms without limits to language. SELECTION CRITERIA:Randomised controlled trials (RCT), cohort studies and case-control studies of HIV-discordant couples in which the HIV-infected member of the couple was being treated or not treated with ART DATA COLLECTION AND ANALYSIS: Abstracts of all trials identified by electronic or bibliographic scanning were examined independently by two authors. We initially identified 3,833 references and examined 87 in detail for study eligibility. Data were abstracted independently using a standardised abstraction form. MAIN RESULTS:One RCT and nine observational studies were included in the review. These ten studies identified 2,112 episodes of HIV transmission, 1,016 among treated couples and 1,096 among untreated couples. The rate ratio for the single randomised controlled trial was 0.04 [95% CI 0.00, 0.27]. All index partners in this study had CD4 cell counts at baseline of 350-550 cells/µL. Similarly, the summary rate ratio for the nine observational studies was 0.58 [95% CI 0.35, 0.96], with substantial heterogeneity (I(2)=64%). After excluding two studies with inadequate person-time data, we estimated a summary rate ratio of 0.36 [95% CI 0.17, 0.75] with substantial heterogeneity (I(2)=62%). We also performed subgroup analyses among the observational studies to see if the effect of ART on prevention of HIV differed by the index partner's CD4 cell count. Among couples in which the infected partner had ?350 CD4 cells/µL, we estimated a rate ratio of 0.12 [95% CI 0.01, 1.99]. In this subgroup, there were 247 transmissions in untreated couples and 30 in treated couples. AUTHORS' CONCLUSIONS:ART is a potent intervention for prevention of HIV in discordant couples in which the index partner has ?550 CD4 cells/µL. A recent multicentre RCT confirms the suspected benefit seen in earlier observational studies and reported in more recent ones. Questions remain about durability of protection, the balance of benefits and adverse events associated with earlier therapy, long-term adherence and transmission of ART-resistant strains to partners. Resource limitations and implementation challenges must also be addressed.Counselling, support, and follow up, as well as mutual disclosure, may have a role in supporting adherence, so programmes should be designed with these components. In addition to ART provision, the operational aspects of delivering such programmes must be considered.
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Project description:BACKGROUND:In Kenya and much of sub-Saharan Africa, nearly half of all couples affected by HIV are discordant. Antiretroviral therapy (ART) slows disease progression in HIV-1-infected individuals and reduces transmission to uninfected partners. We examined time to ART initiation and factors associated with delayed initiation in HIV-1-discordant couples in Nairobi. METHODS:HIV-1-discordant couples were enrolled and followed quarterly for up to 2 years. Clinical staff administered questionnaires and conducted viral loads and CD4 counts. Participants with a CD4 count meeting ART criteria were referred to a nearby US President's Emergency Plan for AIDS Relief-funded treatment center. Barriers to ART initiation among participants with a CD4 count eligible for ART were assessed by Cox regression. RESULTS:Of 439 HIV-1-infected participants (63.6% females and 36.4% males), 146 met CD4 count criteria for ART during follow-up. Median time from meeting CD4 criteria until ART initiation was 8.9 months, with 42.0% of eligible participants on ART by 6 months and 63.4% on ART by 1 year. The CD4 count at the time of eligibility was inversely associated with time to ART initiation (hazard ratio = 0.49, P < 0.001). Compared with homeowners, those paying higher rents started ART 48% more slowly (P = 0.062) and those paying lower rents started 71% more slowly (P = 0.002). CONCLUSIONS:Despite access to regular health care, referrals to treatment centers, and free access to ART, over one-third of participants with an eligible CD4 count had not started ART within 1 year. Factors of lower socioeconomic status may slow ART initiation, and targeted approaches are needed to avoid delays in treatment initiation.
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Project description:BACKGROUND:An estimated one- to-two-thirds of new human immunodeficiency virus (HIV) infections among US men who have sex with men (MSM) occur within the context of primary partnerships. Despite this fact, there remains a lack of prevention interventions that focus on male sero-discordant dyads. Interventions that provide male couples with skills to manage HIV risk, and to support each other towards active engagement in HIV prevention and care, are urgently needed. OBJECTIVE:The objective of this paper is to describe the protocol for an innovative dyadic intervention (Stronger Together) that combines couples' HIV testing and dyadic adherence counseling to improve treatment adherence and engagement in care among HIV sero-discordant male couples in the United States. METHODS:The research activities involve a prospective randomized controlled trial (RCT) of approximately 165 venue- and clinic-recruited sero-discordant male couples (330 individuals: 165 HIV sero-negative and 165 HIV sero-positive). Couples randomized into the intervention arm receive couples' HIV counseling and testing plus dyadic adherence counseling, while those randomized to the control arm receive individual HIV counseling and testing. The study takes place in three cities: Atlanta, GA (study site Emory University); Boston, MA (study site The Fenway Institute); and Chicago, IL (study site Ann & Robert H. Lurie Children's Hospital of Chicago). Cohort recruitment began in 2015. Couples are followed prospectively for 24 months, with study assessments at baseline, 6, 12, 18, and 24 months. RESULTS:Stronger Together was launched in August 2014. To date, 160 couples (97% of the target enrollment) have been enrolled and randomized. The average retention rate across the three sites is 95%. Relationship dissolution has been relatively low, with only 13 couples breaking up during the RCT. Of the 13 couples who have broken up, 10 of the 13 HIV-positive partners have been retained in the cohort; none of these HIV-positive partners have enrolled new partners into the RCT. CONCLUSIONS:The intervention offers a unique opportunity for sero-discordant couples to support each other towards common HIV management goals by facilitating their development of tailored prevention plans via couples-based HIV testing and counseling, as well as problem-solving skills in Partner Strategies to Enhance Problem-solving Skills (STEPS). TRIAL REGISTRATION:ClinicalTrials.gov NCT01772992; https://clinicaltrials.gov/ct2/show/NCT01772992 (Archived by WebCite at http://www.webcitation.org/6szFBVk1R).
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Project description: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.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).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.
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