Intra- and inter-subtype HIV diversity between 1994 and 2018 in southern Uganda: a longitudinal population-based study.

There is limited data on human immunodeficiency virus (HIV) evolutionary trends in African populations. We evaluated changes in HIV viral diversity and genetic divergence in southern Uganda over a 24-year period spanning the introduction and scale-up of HIV prevention and treatment programs using HIV sequence and survey data from the Rakai Community Cohort Study, an open longitudinal population-based HIV surveillance cohort. Gag (p24) and env (gp41) HIV data were generated from people living with HIV (PLHIV) in 31 inland semi-urban trading and agrarian communities (1994-2018) and four hyperendemic Lake Victoria fishing communities (2011-2018) under continuous surveillance. HIV subtype was assigned using the Recombination Identification Program with phylogenetic confirmation. Inter-subtype diversity was evaluated using the Shannon diversity index, and intra-subtype diversity with the nucleotide diversity and pairwise TN93 genetic distance. Genetic divergence was measured using root-to-tip distance and pairwise TN93 genetic distance analyses. Demographic history of HIV was inferred using a coalescent-based Bayesian Skygrid model. Evolutionary dynamics were assessed among demographic and behavioral population subgroups, including by migration status. 9931 HIV sequences were available from 4999 PLHIV, including 3060 and 1939 persons residing in inland and fishing communities, respectively. In inland communities, subtype A1 viruses proportionately increased from 14.3% in 1995 to 25.9% in 2017 (P < .001), while those of subtype D declined from 73.2% in 1995 to 28.2% in 2017 (P < .001). The proportion of viruses classified as recombinants significantly increased by nearly four-fold from 12.2% in 1995 to 44.8% in 2017. Inter-subtype HIV diversity has generally increased. While intra-subtype p24 genetic diversity and divergence leveled off after 2014, intra-subtype gp41 diversity, effective population size, and divergence increased through 2017. Intra- and inter-subtype viral diversity increased across all demographic and behavioral population subgroups, including among individuals with no recent migration history or extra-community sexual partners. This study provides insights into population-level HIV evolutionary dynamics following the scale-up of HIV prevention and treatment programs. Continued molecular surveillance may provide a better understanding of the dynamics driving population HIV evolution and yield important insights for epidemic control and vaccine development.

The potential promise and pitfalls of point-of-care viral load monitoring to expedite HIV treatment decision-making in rural Uganda: a qualitative study.

BACKGROUND: HIV treatment programs in Africa have implemented centralized testing for routine viral load monitoring (VLM), which may result in specimen processing delays inhibiting timely return of viral load results. Decentralized, point-of-care (PoC) VLM is a promising tool for expediting HIV clinical decision-making but remains unavailable in most African settings. We qualitatively explored the perceived feasibility and appropriateness of PoC VLM to address gaps along the viral load monitoring continuum in rural Uganda. METHODS: Between May and September 2022, we conducted 15 in-depth interviews with HIV clinicians (facility in-charges, clinical officers, nurses, counselors) and six focus group discussions with 47 peer health workers from three south-central Ugandan districts. Topics explored centralized VLM implementation and opportunities/challenges to optimizing routine VLM implementation with PoC testing platforms. We explored perspectives on PoC VLM suitability and feasibility using iterative thematic analysis. Applying the Framework Method, we then mapped salient constraints and enablers of PoC VLM to constructs from the Consolidated Framework for Implementation Research. RESULTS: Clinicians and peers alike emphasized centralized viral load monitoring's resource-intensiveness and susceptibility to procedural/infrastructural bottlenecks (e.g., supply stockouts, testing backlogs, community tracing of clients with delayed VLM results), inhibiting timely clinical decision-making. Participants reacted enthusiastically to the prospect of PoC VLM, anticipating accelerated turnarounds in specimen processing, shorter and/or fewer client encounters with treatment services, and streamlined efficiencies in HIV care provision (including expedited VLM-driven clinical decision-making). Anticipated constraints to PoC VLM implementation included human resource requirements for processing large quantities of specimens (especially when machinery require repair), procurement and maintenance costs, training needs in the existing health workforce for operating point-of-care technology, and insufficient space in lower-tier health facilities to accommodate installation of new laboratory equipment. CONCLUSIONS: Anticipated implementation challenges, primarily clustering around resource requirements, did not diminish enthusiasm for PoC VLM monitoring among rural Ugandan clinicians and peer health workers, who perceived PoC platforms as potential solutions to existing inefficiencies within the centralized VLM ecosystem. Prioritizing PoC VLM rollout in facilities with available resources for optimal implementation (e.g., adequate physical and fiscal infrastructure, capacity to manage high specimen volumes) could help overcome anticipated barriers to decentralizing viral load monitoring.

Impact of antimicrobials on penile HIV susceptibility and immunology in uncircumcised men: A randomized phase 1/2 clinical trial.

Within the penile microbiome, bacteria associated with seroconversion, immunology, and cells (BASIC species) enhance HIV susceptibility in heterosexual uncircumcised men by inducing foreskin inflammation and HIV target cell recruitment. This phase 1/2 clinical trial randomizes HIV-uninfected Ugandan men (n = 125) to either oral tinidazole, topical metronidazole, topical clindamycin, or topical hydrogen peroxide to define impact on ex vivo foreskin HIV susceptibility, penile immunology, and BASIC species density. Antimicrobials are well tolerated, and 116 (93%) participants complete the protocol. Topical metronidazole and oral tinidazole reduce the inner foreskin tissue density of HIV-susceptible CD4+ T cells (predefined primary endpoint). Antimicrobials also have varying but substantial effects on reducing prepuce inflammation and BASIC species density, reducing density of foreskin T cell subsets, and increasing foreskin epithelial integrity. Immune alterations correlate strongly with changes in the abundance of BASIC species. Clinical interventions targeting the penile microbiota, particularly topical metronidazole, may reduce HIV susceptibility in uncircumcised men.

Sexually transmitted infections and migration in Uganda: a population-based study.

OBJECTIVES: Migration is associated with increased risk of HIV infection in Africa, but evidence about non-HIV sexually transmitted infection (STI) burden among African migrants is limited. METHODS: We used data from the Sexually Transmitted Infection Prevalence Study, a cross-sectional population-based study of chlamydia, gonorrhoea, trichomoniasis, syphilis and herpes simplex virus type 2 prevalence in southern Uganda, to compare STI prevalence between adults aged 18 and 49 years with and without a recent history of migration. Migration status was determined using household census data, with a recent migration history defined as having moved into one's community of current residence within the last ~18 months. Unadjusted and adjusted modified Poisson regression models were used to compare individual STI prevalence risk by recent migration status with associations reported as adjusted prevalence risk ratios (adjPRRs) with 95% CIs. Adjusted models included participants' sex, age, community type, education, occupation and marital status. RESULTS: Among 1825 participants, 358 (19.6%) had a recent migration history. Overall, migrants exhibited a significantly higher combined prevalence of curable STIs (gonorrhoea, chlamydia, high-titre syphilis (rapid plasma regain ≥1:8) and trichomoniasis) as compared with long-term residents (34.4% vs 24.2%; adjPRR=1.23; 95% CI 1.03 to 1.47). Significant differences in curable STI prevalence by migration status were concentrated among persons living with HIV (49.4% prevalence in migrants vs 32.6% in long-term residents; adjPRR=1.42; 95% CI 1.10 to 1.85) and among women (38.8% in migrants vs 27.8% in long-term residents; adjPRR=1.26; 95% CI 1.01 to 1.58). High-titre syphilis prevalence was especially elevated among male migrants (11.2% in migrants vs 4.9% in long-term residents; adjPRR=1.82; 95% CI 1.06 to 3.13). CONCLUSIONS: The prevalence of non-HIV STIs is higher among migrants. Tailored outreach and service delivery approaches that address the needs of mobile populations are crucial for integrated HIV and STI epidemic control in Uganda to optimise resources and reduce transmission risks.

HIV-1 subtype A1, D, and recombinant proviral genome landscapes during long-term suppressive therapy.

The primary obstacle to curing HIV-1 is a reservoir of CD4+ cells that contain stably integrated provirus. Previous studies characterizing the proviral landscape, which have been predominantly conducted in males in the United States and Europe living with HIV-1 subtype B, have revealed that most proviruses that persist during antiretroviral therapy (ART) are defective. In contrast, less is known about proviral landscapes in females with non-B subtypes, which represents the largest group of individuals living with HIV-1. Here, we analyze genomic DNA from resting CD4+ T-cells from 16 female and seven male Ugandans with HIV-1 receiving suppressive ART (n = 23). We perform near-full-length proviral sequencing at limiting dilution to examine the proviral genetic landscape, yielding 607 HIV-1 subtype A1, D, and recombinant proviral sequences (mean 26/person). We observe that intact genomes are relatively rare and clonal expansion occurs in both intact and defective genomes. Our modification of the primers and probes of the Intact Proviral DNA Assay (IPDA), developed for subtype B, rescues intact provirus detection in Ugandan samples for which the original IPDA fails. This work will facilitate research on HIV-1 persistence and cure strategies in Africa, where the burden of HIV-1 is heaviest.

Age and gender profiles of HIV infection burden and viraemia: novel metrics for HIV epidemic control in African populations with high antiretroviral therapy coverage.

Introduction: To prioritize and tailor interventions for ending AIDS by 2030 in Africa, it is important to characterize the population groups in which HIV viraemia is concentrating. Methods: We analysed HIV testing and viral load data collected between 2013-2019 from the open, population-based Rakai Community Cohort Study (RCCS) in Uganda, to estimate HIV seroprevalence and population viral suppression over time by gender, one-year age bands and residence in inland and fishing communities. All estimates were standardized to the underlying source population using census data. We then assessed 95-95-95 targets in their ability to identify the populations in which viraemia concentrates. Results: Following the implementation of Universal Test and Treat, the proportion of individuals with viraemia decreased from 4.9% (4.6%-5.3%) in 2013 to 1.9% (1.7%-2.2%) in 2019 in inland communities and from 19.1% (18.0%-20.4%) in 2013 to 4.7% (4.0%-5.5%) in 2019 in fishing communities. Viraemia did not concentrate in the age and gender groups furthest from achieving 95-95-95 targets. Instead, in both inland and fishing communities, women aged 25-29 and men aged 30-34 were the 5-year age groups that contributed most to population-level viraemia in 2019, despite these groups being close to or had already achieved 95-95-95 targets. Conclusions: The 95-95-95 targets provide a useful benchmark for monitoring progress towards HIV epidemic control, but do not contextualize underlying population structures and so may direct interventions towards groups that represent a marginal fraction of the population with viraemia.

Household transport ownership and HIV viral suppression in rural Uganda: a cross- sectional, population-based study.

Background: Empirical data on transportation access and HIV treatment outcomes in sub-Saharan Africa are rare. We assessed the association between household transport ownership and HIV viral suppression in rural Uganda. Methods: The study was conducted among people living with HIV aged 15-49 years using cross-sectional data from the Rakai Community Cohort Study (RCCS), collected from June 14, 2018, to November 6, 2020. Transport ownership was defined as household possession of a car, motorcycle, or bicycle. HIV viral suppression was defined as < 1000 HIV RNA copies/ml. Poisson regression with robust variance estimation identified unadjusted and adjusted prevalence ratios and 95% confidence intervals (CI) of HIV viral suppression by transport ownership. Results: The study included 3,060 persons aged 15-49 living with HIV. Overall HIV viral suppression was 86.5% and was higher among women compared to men (89.3% versus 81.6%; adjusted prevalence ratio: 1.14, 95% CI: 1.10, 1.18). A total of 874 participants (28.6%) resided in households that owned at least one means of transport. HIV viral suppression was 79.8% among men and 88.2% among women from households without any means of transport, compared to 85.4% among men and 92.4% among women from households with at least one means of transport. Adjusted prevalence ratios of HIV viral suppression were 1.11 (95% CI: 1.04, 1.18) for males and 1.06 (95% CI: 1.03, 1.10) for females from households owning at least one means of transport compared with those from households with none. Conclusion: There was increased HIV viral suppression among people living with HIV from households with transport means compared to those from households without transport means, suggesting transport may facilitate access to, and continued engagement with, HIV treatment services.

Increasing intra- and inter-subtype HIV diversity despite declining HIV incidence in Uganda.

HIV incidence has been declining in Africa with scale-up of HIV interventions. However, there is limited data on HIV evolutionary trends in African populations with waning epidemics. We evaluated changes in HIV viral diversity and genetic divergence in southern Uganda over a twenty-five-year period spanning the introduction and scale-up of HIV prevention and treatment programs using HIV sequence and survey data from the Rakai Community Cohort Study, an open longitudinal population-based HIV surveillance cohort. Gag (p24) and env (gp41) HIV data were generated from persons living with HIV (PLHIV) in 31 inland semi-urban trading and agrarian communities (1994 to 2018) and four hyperendemic Lake Victoria fishing communities (2011 to 2018) under continuous surveillance. HIV subtype was assigned using the Recombination Identification Program with phylogenetic confirmation. Inter-subtype diversity was estimated using the Shannon diversity index and intra-subtype diversity with the nucleotide diversity and pairwise TN93 genetic distance. Genetic divergence was measured using root-to-tip distance and pairwise TN93 genetic distance analyses. Evolutionary dynamics were assessed among demographic and behavioral sub-groups, including by migration status. 9,931 HIV sequences were available from 4,999 PLHIV, including 3,060 and 1,939 persons residing in inland and fishing communities, respectively. In inland communities, subtype A1 viruses proportionately increased from 14.3% in 1995 to 25.9% in 2017 (p<0.001), while those of subtype D declined from 73.2% in 1995 to 28.2% in 2017 (p<0.001). The proportion of viruses classified as recombinants significantly increased by more than four-fold. Inter-subtype HIV diversity has generally increased. While p24 intra-subtype genetic diversity and divergence leveled off after 2014, diversity and divergence of gp41 increased through 2017. Inter- and intra-subtype viral diversity increased across all population sub-groups, including among individuals with no recent migration history or extra-community sexual partners. This study provides insights into population-level HIV evolutionary dynamics in declining African HIV epidemics following the scale-up of HIV prevention and treatment programs. Continued molecular surveillance may provide a better understanding of the dynamics driving population HIV evolution and yield important insights for epidemic control and vaccine development.

Effective and targeted latency reversal in CD4+ T cells from individuals on long term combined antiretroviral therapy initiated during chronic HIV-1 infection.

To date, an affordable, effective treatment for an HIV-1 cure remains only a concept with most "latency reversal" agents (LRAs) lacking specificity for the latent HIV-1 reservoir and failing in early clinical trials. We assessed HIV-1 latency reversal using a multivalent HIV-1-derived virus-like particle (HLP) to treat samples from 32 people living with HIV-1 (PLWH) in Uganda, US and Canada who initiated combined antiretroviral therapy (cART) during chronic infection. Even after 5-20 years on stable cART, HLP could target CD4+ T cells harbouring latent HIV-1 reservoir resulting in 100-fold more HIV-1 release into culture supernatant than by common recall antigens, and 1000-fold more than by chemotherapeutic LRAs. HLP induced release of a divergent and replication-competent HIV-1 population from PLWH on cART. These findings suggest HLP provides a targeted approach to reactivate the majority of latent HIV-1 proviruses among individuals infected with HIV-1.

Effect of cryopreservation on CD4+ T cell subsets in foreskin tissue.

Voluntary medical male circumcision (VMMC) reduces HIV acquisition by at least 60%, but the determinants of HIV susceptibility in foreskin tissues are incompletely understood. Flow cytometry is a powerful tool that helps us understand tissue immune defenses in mucosal tissue like the inner foreskin, but foreskin flow cytometry has only been validated using fresh tissue samples. This restricts immune analyses to timepoints immediately after surgical acquisition and hinders research in this area. We compared fresh analysis with whole tissue cryopreservation and later thawing and digestion to analyze CD4+ T cell populations relevant to HIV susceptibility (CCR5, CD25, CD127, CCR4, CXCR3, CCR6, CCR10, HLA-DR, and CD38). Eight foreskin samples from HIV-negative males aged >18 years were collected after VMMC. For each sample, half the foreskin was immediately cryopreserved for later digestion and flow cytometry analysis, while the remaining tissues were analyzed fresh. We demonstrate no significant impact of cryopreservation on CD4+ T cell expression of CD25, CCR4, CCR6, HLA-DR, CCR10, or CD127. Although expression levels of CCR5, CD38, and CXCR3 were increased after cryopreservation, the relative ranking of participants was retained. In conclusion, cryopreserved foreskin tissues may be suitable for subsequent digestion and flow cytometry phenotyping of HIV-susceptible T cell populations.

Temporary increase in circulating replication-competent latent HIV-infected resting CD4+ T cells after switch to an integrase inhibitor based antiretroviral regimen.

BACKGROUND: The principal barrier to an HIV cure is the presence of the latent viral reservoir (LVR), which has been understudied in African populations. From 2018 to 2019, Uganda instituted a nationwide rollout of ART consisting of Dolutegravir (DTG) with two NRTI, which replaced the previous regimen of one NNRTI and the same two NRTI. METHODS: Changes in the inducible replication-competent LVR (RC-LVR) of ART-suppressed Ugandans with HIV (n = 88) from 2015 to 2020 were examined using the quantitative viral outgrowth assay. Outgrowth viruses were examined for viral evolution. Changes in the RC-LVR were analyzed using three versions of a Bayesian model that estimated the decay rate over time as a single, linear rate (model A), or allowing for a change at time of DTG initiation (model B&C). FINDINGS: Model A estimated the slope of RC-LVR change as a non-significant positive increase, which was due to a temporary spike in the RC-LVR that occurred 0-12 months post-DTG initiation (p < 0.005). This was confirmed with models B and C; for instance, model B estimated a significant decay pre-DTG initiation with a half-life of 6.9 years, and an ∼1.7-fold increase in the size of the RC-LVR post-DTG initiation. There was no evidence of viral failure or consistent evolution in the cohort. INTERPRETATION: These data suggest that the change from NNRTI- to DTG-based ART is associated with a significant temporary increase in the circulating RC-LVR. FUNDING: Supported by the NIH (grant 1-UM1AI164565); Gilead HIV Cure Grants Program (90072171); Canadian Institutes of Health Research (PJT-155990); and Ontario Genomics-Canadian Statistical Sciences Institute.

Temporal dynamics and drivers of durable HIV viral load suppression and persistent high- and low-level viraemia during Universal Test and Treat scale-up in Uganda: a population-based study.

INTRODUCTION: Population-level data on durable HIV viral load suppression (VLS) following the implementation of Universal Test and Treat (UTT) in Africa are limited. We assessed trends in durable VLS and viraemia among persons living with HIV in 40 Ugandan communities during the UTT scale-up. METHODS: In 2015-2020, we measured VLS (<200 RNA copies/ml) among participants in the Rakai Community Cohort Study, a longitudinal population-based HIV surveillance cohort in southern Uganda. Persons with unsuppressed viral loads were characterized as having low-level (200-999 copies/ml) or high-level (≥1000 copies/ml) viraemia. Individual virologic outcomes were assessed over two consecutive RCCS survey visits (i.e. visit-pairs; ∼18-month visit intervals) and classified as durable VLS (<200 copies/ml at both visits), new/renewed VLS (<200 copies/ml at follow-up only), viral rebound (<200 copies/ml at initial visit only) or persistent viraemia (≥200 copies/ml at both visits). Population prevalence of each outcome was assessed over calendar time. Community-level prevalence and individual-level predictors of persistent high-level viraemia were also assessed using multivariable Poisson regression with generalized estimating equations. RESULTS: Overall, 3080 participants contributed 4604 visit-pairs over three survey rounds. Most visit-pairs (72.4%) exhibited durable VLS, with few (2.5%) experiencing viral rebound. Among those with any viraemia at the initial visit (23.5%, n = 1083), 46.9% remained viraemic through follow-up, 91.3% of which was high-level viraemia. One-fifth (20.8%) of visit-pairs exhibiting persistent high-level viraemia self-reported antiretroviral therapy (ART) use for ≥12 months. Prevalence of persistent high-level viraemia varied substantially across communities and was significantly elevated among young persons aged 15-29 years (vs. 40- to 49-year-olds; adjusted risk ratio [adjRR] = 2.96; 95% confidence interval [95% CI]: 2.21-3.96), males (vs. females; adjRR = 2.40, 95% CI: 1.87-3.07), persons reporting inconsistent condom use with non-marital/casual partners (vs. persons with marital/permanent partners only; adjRR = 1.38, 95% CI: 1.10-1.74) and persons reporting hazardous alcohol use (adjRR = 1.09, 95% CI: 1.03-1.16). The prevalence of persistent high-level viraemia was highest among males <30 years (32.0%). CONCLUSIONS: Following universal ART provision, most persons living with HIV in south-central Uganda are durably suppressed. Among persons exhibiting any viraemia, nearly half exhibited high-level viraemia for ≥12 months and reported higher-risk behaviours associated with onward HIV transmission. Intensified efforts linking individuals to HIV treatment services could accelerate momentum towards HIV epidemic control.

Longitudinal patterns in indeterminate HIV rapid antibody test results: a population-based, prospective cohort study.

Rapid HIV tests are critical to HIV surveillance and universal testing and treatment programs. We assessed longitudinal patterns in indeterminate HIV rapid test results in an African population-based cohort. Prospective HIV rapid antibody test results, defined by two parallel rapid tests, among participants aged 15-49 years from three survey rounds of the Rakai Community Cohort Study, Uganda, from 2013 to 2018, were assessed. An indeterminate result was defined as any weak positive result or when one test was negative and the other was positive. A total of 31,405 participants contributed 54,459 person-visits, with 15,713 participants contributing multiple visits and 7,351 participants contributing 3 visits. The prevalence of indeterminate results was 2.7% (1,490/54,469). Of the participants with multiple visits who initially tested indeterminate (n = 591), 40.4% were negative, 18.6% were positive, and 41.0% were indeterminate at the subsequent visit. Of the participants with two consecutive indeterminate results who had a third visit (n = 67), 20.9% were negative, 9.0% were positive, and 70.2% remained indeterminate. Compared to a prior negative result, a prior indeterminate result was strongly associated with a subsequent indeterminate result [adjusted prevalence ratio, 23.0 (95% CI = 20.0-26.5)]. Compared to men, women were more likely to test indeterminate than negative [adjusted odds ratio, 2.3 (95% CI = 2.0-2.6)]. Indeterminate rapid HIV test results are highly correlated within an individual and 0.6% of the population persistently tested indeterminate over the study period. A substantial fraction of people with an indeterminate result subsequently tested HIV positive at the next visit, underscoring the importance of follow-up HIV testing protocols.IMPORTANCERapid HIV tests are a critical tool for expanding HIV testing and treatment to end the HIV epidemic. The interpretation and management of indeterminate rapid HIV test results pose a unique challenge for connecting all people living with HIV to the necessary care and treatment. Indeterminate rapid HIV test results are characterized by any weak positive result or discordant results (when one test is negative and the other is positive). We systematically tested all participants of a Ugandan population-based, longitudinal cohort study regardless of prior test results or HIV status to quantify longitudinal patterns in rapid HIV test results. We found that a substantial fraction (>15%) of participants with indeterminate rapid test results subsequently tested positive upon follow-up testing at the next visit. Our findings demonstrate the importance of follow-up HIV testing protocols for indeterminate rapid HIV test results.

Insertive vaginal sex is associated with altered penile immunology and enrichment of Gardnerella vaginalis in uncircumcised Ugandan men.

PROBLEM: HIV susceptibility is linked to the penile immune milieu (particularly IL-8 levels) and microbiome. The effects of insertive vaginal sex itself on penile immunology and microbiota are not well described. METHOD OF STUDY: We compared the immune milieu and microbiology of the coronal sulcus (CS) and distal urethra in 47 uncircumcised Ugandan men reporting ever (n = 42) or never (n = 5) having had vaginal intercourse. Soluble immune factors were assayed by multiplex ELISA, and penile bacteria abundance by 16S rRNA qPCR and sequencing. Co-primary endpoints were penile levels of IL-8 and soluble E-cadherin. RESULTS: Independent of classical STIs, men reporting prior vaginal sex demonstrated elevated IL-8 levels in both the coronal sulcus (1.78 vs. 0.81 log10 pg/mL, p = .021) and urethra (2.93 vs. 2.30 log10 pg/mL; p = .003), with a strong inverse relationship between urethral IL-8 levels and the time from last vaginal sex (r = -0.436; p = .004). Vaginal sex was also associated with elevated penile IL-1α/ß and soluble E-cadherin (sEcad), a marker of epithelial disruption. Gardnerella vaginalis (Gv) was only present in the penile microbiome of men reporting prior vaginal sex, and urethral Gv absolute abundance was strongly associated with urethral inflammation (r = 0.556; p < .001); corynebacteria were enriched in the CS of men reporting no prior vaginal sex and were associated with reduced CS inflammation. CONCLUSIONS: Sexual intercourse was associated with sustained changes in penile immunology, potentially mediated through microbial alterations, in particular the urethral abundance of G. vaginalis. Future studies should further characterize the effects of sexual debut on penile bacteria and immunology.

Longitudinal population-level HIV epidemiologic and genomic surveillance highlights growing gender disparity of HIV transmission in Uganda.

HIV incidence in eastern and southern Africa has historically been concentrated among girls and women aged 15-24 years. As new cases decline with HIV interventions, population-level infection dynamics may shift by age and gender. Here, we integrated population-based surveillance of 38,749 participants in the Rakai Community Cohort Study and longitudinal deep-sequence viral phylogenetics to assess how HIV incidence and population groups driving transmission have changed from 2003 to 2018 in Uganda. We observed 1,117 individuals in the incidence cohort and 1,978 individuals in the transmission cohort. HIV viral suppression increased more rapidly in women than men, however incidence declined more slowly in women than men. We found that age-specific transmission flows shifted: whereas HIV transmission to girls and women (aged 15-24 years) from older men declined by about one-third, transmission to women (aged 25-34 years) from men that were 0-6 years older increased by half in 2003 to 2018. Based on changes in transmission flows, we estimated that closing the gender gap in viral suppression could have reduced HIV incidence in women by half in 2018. This study suggests that HIV programmes to increase HIV suppression in men are critical to reduce incidence in women, close gender gaps in infection burden and improve men's health in Africa.

Incidence of Health Facility Switching and Associations With HIV Viral Rebound Among Persons on Antiretroviral Therapy in Uganda: A Population-based Study.

BACKGROUND: A substantial proportion of persons on antiretroviral therapy (ART) considered lost to follow-up have actually transferred their human immunodeficiency virus (HIV) care to other facilities. However, the relationship between facility switching and virologic outcomes, including viral rebound, is poorly understood. METHODS: We used data from 40 communities (2015-2020) in the Rakai Community Cohort Study to estimate incidence of facility switching and viral rebound. Persons aged 15-49 years with serologically confirmed HIV who self-reported ART use and contributed ≥1 follow-up visit were included. Facility switching and virologic outcomes were assessed between 2 consecutive study visits (ie, index and follow-up visits, interval of approximately 18 months). Those who reported different HIV treatment facilities between index and follow-up study visits were classified as having switched facilities. Virologic outcomes included viral rebound among individuals initially suppressed (<200 copies/mL). Multivariable Poisson regression was used to estimate associations between facility switching and viral rebound. RESULTS: Overall, 2257 persons who self-reported ART use (median age, 35 years; 65% female, 92% initially suppressed) contributed 3335 visit-pairs and 5959 person-years to the analysis. Facility switching was common (4.8 per 100 person-years; 95% confidence interval [CI], 4.2-5.5) and most pronounced in persons aged <30 years and fishing community residents. Among persons suppressed at their index visit (n = 2076), incidence of viral rebound was more than twice as high in persons who switched facilities (adjusted incidence rate ratio = 2.27; 95% CI, 1.16-4.45). CONCLUSIONS: Facility switching was common and associated with viral rebound among persons initially suppressed. Investments in more agile, person-centered models for mobile clients are needed to address system inefficiencies and bottlenecks that can disrupt HIV care continuity.

Proportion of Ugandans with pre-pandemic SARS-CoV-2 cross-reactive CD4+ and CD8+ T-cell responses: A pilot study.

The estimated mortality rate of the SARS-CoV-2 pandemic varied greatly around the world. In particular, multiple countries in East, Central, and West Africa had significantly lower rates of COVID-19 related fatalities than many resource-rich nations with significantly earlier wide-spread access to life-saving vaccines. One possible reason for this lower mortality could be the presence of pre-existing cross-reactive immunological responses in these areas of the world. To explore this hypothesis, an exploratory study of stored peripheral blood mononuclear cells (PBMC) from Ugandans collected from 2015-2017 prior to the COVID-19 pandemic (n = 29) and from hospitalized Ugandan COVID-19 patients (n = 3) were examined using flow-cytometry for the presence of pre-existing SARS-CoV-2 cross-reactive CD4+ and CD8+ T-cell populations using four T-cell epitope mega pools. Of pre-pandemic participants, 89.7% (26/29) had either CD4+ or CD8+, or both, SARS-CoV-2 specific T-cell responses. Specifically, CD4+ T-cell reactivity (72.4%) and CD8+ T-cell reactivity (65.5%) were relatively similar, and 13 participants (44.8%) had both types of cross-reactive types of T-cells present. There were no significant differences in response by sex in the population, however this may be in part due to the limited sample size examined. The rates of cross-reactive T-cell populations in this exploratory Ugandan population appears higher than previous estimates from resource-rich countries like the United States (20-50% reactivity). It is unclear what role, if any, this cross-reactivity played in decreasing COVID-19 related mortality in Uganda and other African countries, but does suggest that a better understanding of global pre-existing immunological cross-reactivity could be an informative data of epidemiological intelligence moving forward.

A moving target: impacts of lowering viral load suppression cutpoints on progress towards HIV epidemic control goals.

Redefining viral load suppression (VLS) using lower cutpoints could impact progress towards the United Nations Programme on HIV/AIDS 95-95-95 targets. We assessed impacts of lowering the VLS cutpoint on achieving the 'third 95' in the Rakai Community Cohort Study. Population VLS would fall from 86% to 84% and 76%, respectively, after lowering VLS cutpoints from <1000 to <200 and <50 copies/ml. The fraction of viremic persons increased by 17% after lowering the VLS cutpoint from <1000 to <200 copies/ml.

Temporal dynamics and drivers of durable HIV viral load suppression and persistent high- and low-level viremia during Universal Test and Treat scale-up in Uganda: a population-based study.

Introduction: Population-level data on durable HIV viral load suppression (VLS) following implementation of Universal Test and Treat (UTT) in Africa are limited. We assessed trends in durable VLS and viremia among persons living with HIV in 40 Ugandan communities during UTT scale-up. Methods: In 2015-2020, we measured VLS (defined as <200 RNA copies/mL) among participants in the Rakai Community Cohort Study, a longitudinal population-based HIV surveillance cohort in southern Uganda. Persons with unsuppressed viral loads were characterized as having low-level (200-999 copies/mL) or high-level (≥1,000 copies/mL) viremia. Individual virologic outcomes were assessed over two consecutive RCCS survey visits (i.e., visit-pairs; ∼18 month visit intervals) and classified as durable VLS (<200 copies/mL at both visits), new/renewed VLS (<200 copies/mL at follow-up only), viral rebound (<200 copies/mL at initial visit only), or persistent viremia (<200 copies/mL at neither visit). Population prevalence of each outcome was assessed over calendar time. Community-level prevalence and individual-level predictors of persistent high-level viremia were also assessed using multivariable Poisson regression with generalized estimating equations. Results: Overall, 3,080 participants contributed 4,604 visit-pairs over three survey rounds. Most visit-pairs (72.4%) exhibited durable VLS, with few (2.5%) experiencing viral rebound. Among those with viremia at the initial visit ( n =1,083), 46.9% maintained viremia through follow-up, 91.3% of which was high-level viremia. One-fifth (20.8%) of visit-pairs exhibiting persistent high-level viremia self-reported antiretroviral therapy (ART) use for ≥12 months. Prevalence of persistent high-level viremia varied substantially across communities and was significantly elevated among young persons aged 15-29 years (versus 40-49-year-olds; adjusted risk ratio [adjRR]=2.96; 95% confidence interval [95%CI]:2.21-3.96), men (versus women; adjRR=2.40, 95%CI:1.87-3.07), persons reporting inconsistent condom use with non-marital/casual partners (versus persons with marital/permanent partners only; adjRR=1.38, 95%CI:1.10-1.74), and persons exhibiting hazardous alcohol use (adjRR=1.09, 95%CI:1.03-1.16). The prevalence of persistent high-level viremia was highest among men <30 years (32.0%). Conclusions: Following universal ART provision, most persons living with HIV in south-central Uganda are durably suppressed. Among persons exhibiting viremia, nearly half maintain high-level viremia for ≥12 months and report higher-risk behaviors associated with onward HIV transmission. Enhanced linkage to HIV care and optimized treatment retention could accelerate momentum towards HIV epidemic control.

Temporary increase in circulating replication-competent latent HIV-infected resting CD4+ T cells after switch to an integrase inhibitor based antiretroviral regimen.

The principal barrier to an HIV cure is the presence of a latent viral reservoir (LVR) made up primarily of latently infected resting CD4+ (rCD4) T-cells. Studies in the United States have shown that the LVR decays slowly (half-life=3.8 years), but this rate in African populations has been understudied. This study examined longitudinal changes in the inducible replication competent LVR (RC-LVR) of ART-suppressed Ugandans living with HIV (n=88) from 2015-2020 using the quantitative viral outgrowth assay, which measures infectious units per million (IUPM) rCD4 T-cells. In addition, outgrowth viruses were examined with site-directed next-generation sequencing to assess for possible ongoing viral evolution. During the study period (2018-19), Uganda instituted a nationwide rollout of first-line ART consisting of Dolutegravir (DTG) with two NRTI, which replaced the previous regimen that consisted of one NNRTI and the same two NRTI. Changes in the RC-LVR were analyzed using two versions of a novel Bayesian model that estimated the decay rate over time on ART as a single, linear rate (model A) or allowing for an inflection at time of DTG initiation (model B). Model A estimated the population-level slope of RC-LVR change as a non-significant positive increase. This positive slope was due to a temporary increase in the RC-LVR that occurred 0-12 months post-DTG initiation (p<0.0001). This was confirmed with model B, which estimated a significant decay pre-DTG initiation with a half-life of 7.7 years, but a significant positive slope post-DTG initiation leading to a transient estimated doubling-time of 8.1 years. There was no evidence of viral failure in the cohort, or consistent evolution in the outgrowth sequences associated with DTG initiation. These data suggest that either the initiation of DTG, or cessation of NNRTI use, is associated with a significant temporary increase in the circulating RC-LVR.