The HIV epidemic in Southern Africa - Is an AIDS-free generation possible?

Assessing the uncertainty around age-mixing patterns in HIV transmission inferred from phylogenetic trees

Understanding age-mixing patterns in Human Immunodeficiency Virus (HIV) transmission networks can enhance the design and implementation of HIV prevention strategies in sub-Saharan Africa. Due to ethical consideration, it is less likely possible to conduct a benchmark study to assess which sampling strategy, and sub-optimal sampling coverage which can yield best estimates for these patterns. We conducted a simulation study, using phylogenetic trees to infer estimates of age-mixing patterns in HIV transmission, through the computation of proportions of pairings between men and women, who were phylogenetically linked across different age groups (15-24 years, 25-39 years, and 40-49 years); and the means, and standard deviations of their age difference. We investigated also the uncertainty around these estimates as a function of the sampling coverage in four sampling strategies: when missing sequence data were missing completely at random (MCAR), and missing at random (MAR) with at most 30%-50%-70% of women in different age groups being in the sample. The results suggested that age-mixing patterns in HIV transmission can be unveiled from proportions of phylogenetic pairings between men and women across age groups; and the mean, and standard deviation of their age difference. A 55% sampling coverage was sufficient to provide the best values of estimates of age-mixing patterns in HIV transmission with MCAR scenario. But we should be cautious in interpreting proportions of men phylogenetically linked to women because they may be overestimated or underestimated, even at higher sampling coverage. The findings showed that, MCAR was the best sampling strategy. This means, it is advisable not to use sequence data collected in settings where we can find a systematic imbalance of age and gender to investigate age-mixing in HIV transmission. If not possible, ensure to take into consideration the imbalance in interpreting the results.

Echinococcosis in humans and animals in Southern Africa Development Community countries: A systematic review

The taeniid Echinococcus is the causative agent of the zoonotic disease echinococcosis/hydatidosis and is associated with economic losses in livestock production. This review summarizes available scientific literature on circulating species of Echinococcus in humans, wild and domestic animals in countries of Southern Africa Development Community, and identifies knowledge gaps and recommend research priorities. Data were systematically accessed from Google Scholar, MEDLINE/PubMed and from library resources from December 2017 to June 2019. Meta-analysis was conducted in STATA program and heterogeneity and prevalence values were pooled by host species with 95% confidence interval. In intermediate hosts, the overall prevalence of Echinococcus by meat inspection was 10% (CI: 9-11%) in small ruminants, 7% (CI: 5-8%) in cattle, 1% (CI: 0-1%) in pigs and 9% (CI: 0-29%) in wild herbivores. In canids by CoproAg-ELISA and necropsy the prevalence was of 10% (CI: 8-10%) and 6% (CI: 3-10%) respectively. A high level of heterogeneity (I2 > 65%) was observed for all study groups. Echinococcus equinus, E. canadensis, E ortleppi and E. felidis were reported from wildlife and E. ortleppi, E. granulosus s. s. and E. canadensis from humans. There is paucity of research in echinococcosis and gaps in prevalence reports over time in both humans and animals in the SADC region and we recommend an increase in future studies on the epidemiology of disease, risk factors for transmission in animals and humans and its relation with human health specially in the advent of HIV pandemic following a "One Health" approach.

Targeting the HIV Epidemic in South Africa: The Need for Testing and Linkage to Care in Emergency Departments

BACKGROUND

The Eastern Cape province of South Africa has one of the highest burdens of HIV in the world. Emergency Departments (EDs) can serve as optimal clinical sites for the identification of new HIV infections and entry into care. We sought to determine the current burden of HIV disease among ED patients in the Eastern Cape.

METHODS

We conducted a prospective cross-sectional observational study in the EDs of three Hospitals in the Eastern Cape province of South Africa from June 2017 to July 2018. All adult, non-critical patients presenting to the ED were systematically approached and offered a Point-Of-Care (POC) HIV test in accordance with South African guidelines. All HIV-positive individuals had their blood tested for the presence of antiretroviral therapy (ART) and the presence of viral suppression (≤ 1000 copies/ml). HIV incidence was estimated using a multi-assay algorithm, validated for a subtype C epidemic.

FINDINGS

Of the 2901 patients for whom HIV status was determined (either known HIV-positive or underwent POC HIV testing), 811 (28.0%) were HIV positive, of which 234 (28.9%) were newly diagnosed. HIV prevalence was higher in Mthatha [34% (388/1134) at Mthatha Regional Hospital and 28% (142/512) at Nelson Mandela Academic Hospital], compared to Port Elizabeth [22% (281/1255) at Livingstone Hospital]. HIV incidence was estimated at 4.5/100 person-years (95% CI: 2.4, 6.50) for women and 1.5 (CI 0.5, 2.5) for men. Of all HIV positive individuals tested for ART (585), 54% (316/585) tested positive for the presence of ARTs, and for all HIV positive participants with viral load data (609), 49% (299/609) were found to be virally suppressed.

INTERPRETATION

Our study not only observed a high prevalence and incidence of HIV among ED patients but also highlights significant attrition along the HIV care cascade for HIV positive individuals. Furthermore, despite developing an optimal testing environment, we were only able to enrol a small sub-set of the ED population. Given the high HIV prevalence and high attrition in the ED population, HIV services in the ED should also develop strategies that can accommodate large testing volumes and ART initiation.

Microbicides for topical immunoprevention of HIV infection

Microbicides are antiseptic topical drugs that help directly or indirectly inhibit the penetration of an infectious agent into the human body, thereby preventing the sexual transmission of HIV-infection and other sexually transmitted diseases. Microbicides have an antiviral mechanism of action in the sexual transmission of HIV and affect the components of mucosal immunity in the vagina. In this article, the pharmaceutical and biomedical aspects of microbicide application are examined and diverse classifications of microbicides are presented. For each group of chemicals, the most important representatives and their mechanisms of action are described. This article also presents the structure and function of mucosal immunity, and shows the importance of the mucosal immune response in the sexual transmission of HIV. This work also exhibits the experimental models for testing of candidate microbicides. For each compound described, a review of preclinical research and clinical trials is provided, covering its development as a microbicide. This paper gives an overview of microbicides, a new class of chemically diverse immunobiological medications reducing the risk of sexual transmission of HIV. The use of microbicides is believed to curb the HIV/AIDS epidemic in the nearest future.

Feasibility and yield of HIV screening among adult trauma patients presenting to an urban emergency department of a tertiary referral hospital in Tanzania

BACKGROUND

The World Health Organization and Tanzanian National Guidelines for HIV and AIDS management, recommends provider initiated testing and counseling for HIV at any point of health care contact. In Tanzania, over 45% of people living with HIV are unaware of their HIV positive status. We determine the feasibility and yield of HIV screening among otherwise healthy adult trauma patients presenting to the first full-capacity Emergency Department in Tanzania.

METHODS

This was a prospective cohort study of consecutive adult trauma patients presenting to Emergency Medicine Department at Muhimbili National Hospital (EMD-MNH) in Dar es Salaam, from March 2017 to September 2017. Eligible patients provided informed consent, pre and post-test counseling was done. Structured case report forms were completed, documenting demographics, acceptance of testing, results and readiness to receive results. Outcomes were the proportion of patients accepting testing, proportion of positive tests, readiness of the patient to receive the results, and proportion of patients who had an HIV test ordered as part of care.

RESULTS

We screened 2848 trauma patients, and enrolled 326 (11.5%) eligible patients. Median age was 33 (IQR 25-42 years), and 248 (76.0%) of participants were male. Of those enrolled, 250 (76.7%) patients accepted testing for HIV, and among them 247 (98.8%) were ready to receive their test results. Of those tested, 14 (5.6%) were found to be HIV positive and 12 were ready to receive results. Two months post hospital discharge 6 (50%), of those who were informed of positive results had visited Care and Treatment Clinics (CTC) for HIV treatment. Three additional patients had not yet attended and three could not be reached. The treating ED physician tested none of the enrolled patients for HIV as part of their regular treatment.

CONCLUSIONS

In our cohort of adult trauma patients presenting to ED, routine HIV screening for unrelated reason, was feasible and acceptable. The yield is sufficient to warrant an on-going program and superior to having physicians choose which patients to test. Future studies should focus on factors affecting the linkage to CTC among HIV positive patients identified at the ED.

Differing psychological vulnerabilities among behaviourally and perinatally HIV infected adolescents in South Africa - implications for targeted health service provision

HIV infections are growing the fastest amongst adolescents, especially in sub Saharan Africa. On reaching adolescence, perinatally-infected youth may have different needs to those who acquired infection behaviourally. Yet both have sub-optimal adherence with implications for their own health as well as onward transmission. This study uses the world's largest community-based study of HIV-positive adolescents from the Eastern Cape, South Africa. Clinic records at N = 53 district health facilities generated a log of all ART-initiated adolescents who were then interviewed in the community: N = 1058 (90%) were tracked and participated. Ethical approval, informed consent and data collector training preceded data gathering. Inventories comprised validated measures of mental health (depression, anxiety, suicidality and internalised stigma), substance use, ART adherence, and clinic attendance. Analyses were conducted using SPSS25 and STATA15. Perinatally-infected adolescents (n = 792, 77.3%) were significantly more likely to be ART adherent (OR = 1.54 95%CI: 1.14-2.07 p = 0.005), retained in healthcare (OR = 1.59 95%CI1.18-2.14 p = 0.002), and treated well by clinic staff (OR = 2.12 95%CI1.59-3.07 p ≤ 0.001). Behaviourally-infected adolescents were more likely to be depressed (B = 0.81 p ≤ 0.001), anxious (B = 1.36 p ≤ 0.001), report internalised stigma (B = 0.91 p ≤ 0.001), express suicidal ideation (OR = 3.65 95%CI: 1.96-6.82 p ≤ 0.001) and report excessive substance use in the past year (OR = 9.37 95%CI5.73-15.35 p ≤ 0.001). Being older explained most of these differences, with female adolescents living with HIV more likely to report suicidal ideation. However, behaviourally-infected adolescents were more likely to report substance use (OR = 2.69 95%CI: 1.48-4.91 p = 0.001), depression (B = 0.406, p = 0.022), anxiety (B = 1.359, p ≤ 0.001), and internalised stigma (B = 0.403, p = 0.007) in multivariate regression analyses, controlling for covariates. Moderation analyses (adjusting for multiple testing) suggest that behaviourally-infected HIV-positive adolescents who are also maternal orphans are more likely to report higher rates of depression (B = 1.075, p < 0.001). These notable differences by mode of infection suggest that studies which conflate HIV-positive adolescents may blur the clinical and psychological experiences of these two different sub-populations. Drivers of non-adherence, poor retention in care, and mental health problems may differ by mode of infection, requiring tailored interventions. Health and social service provision, if it is to be effective, needs to address these different youth profiles to ensure optimal adherence, development and wellbeing throughout the life course.

Partner age differences and associated sexual risk behaviours among adolescent girls and young women in a cash transfer programme for schooling in Malawi

Background

Age disparities in sexual relationships have been proposed as a key risk factor for HIV transmission in Sub-Saharan Africa, but evidence remains inconclusive. The SIHR study, a cluster randomised trial of a cash transfer programme in Malawi, found that young women in the intervention groups were less likely to have had a sexual partner aged 25 or older, and less likely to test positive for HIV and HSV-2 at follow-up compared to control groups. We examined the hypotheses that girls in the intervention groups had smaller age differences than control groups and that large age differences were associated with relationship-level HIV transmission risk factors: inconsistent condom use, sex frequency, and relationship duration.

Methods

We conducted an analysis of schoolgirls in the Schooling, Income, and Health Risk (SIHR) study aged 13-22 at baseline (n = 2907). We investigated the effects of study arm, trial stage and participant age on age differences in sexual relationships using a linear mixed-effects model. Cumulative-link mixed-effects models were used to estimate the effect of relationship age difference on condom use and sex frequency, and a Cox proportional hazard model was used to estimate the effect of relationship age difference on relationship duration. We controlled for the girl’s age, number of partners, study group and study round.

Results

Girls receiving cash transfers, on average, had smaller age differences in relationships compared to controls, though the estimated difference was not statistically significant (− 0.43 years; 95% CI: -1.03, 0.17). The older the participant was, the smaller her age differences (− 0.67 per 4-year increase in age; 95% CI: -0.99, − 0.35). Among controls, after the cash transfers had ended the average age difference was 0.82 years larger than during the intervention (95% CI: 0.43, 1.21), suggesting a possible indirect effect of the study on behaviour in the community as a whole. Across treatment groups, larger age differences in relationships were associated with lower levels of condom use, more frequent sex, and longer relationship durations.

Conclusions

Cash-transfer programmes may prevent HIV transmission in part by encouraging young women to form age-similar relationships, which are characterised by increased condom use and reduced sex frequency. The benefits of these programmes may extend to those who are not directly receiving the cash.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5327-7) contains supplementary material, which is available to authorized users.

HIV prevalence and behavioral and psychosocial factors among transgender women and cisgender men who have sex with men in 8 African countries: A cross-sectional analysis

INTRODUCTION

Sub-Saharan Africa bears more than two-thirds of the worldwide burden of HIV; however, data among transgender women from the region are sparse. Transgender women across the world face significant vulnerability to HIV. This analysis aimed to assess HIV prevalence as well as psychosocial and behavioral drivers of HIV infection among transgender women compared with cisgender (non-transgender) men who have sex with men (cis-MSM) in 8 sub-Saharan African countries.

METHODS AND FINDINGS

Respondent-driven sampling targeted cis-MSM for enrollment. Data collection took place at 14 sites across 8 countries: Burkina Faso (January-August 2013), Côte d'Ivoire (March 2015-February 2016), The Gambia (July-December 2011), Lesotho (February-September 2014), Malawi (July 2011-March 2012), Senegal (February-November 2015), Swaziland (August-December 2011), and Togo (January-June 2013). Surveys gathered information on sexual orientation, gender identity, stigma, mental health, sexual behavior, and HIV testing. Rapid tests for HIV were conducted. Data were merged, and mixed effects logistic regression models were used to estimate relationships between gender identity and HIV infection. Among 4,586 participants assigned male sex at birth, 937 (20%) identified as transgender or female, and 3,649 were cis-MSM. The mean age of study participants was approximately 24 years, with no difference between transgender participants and cis-MSM. Compared to cis-MSM participants, transgender women were more likely to experience family exclusion (odds ratio [OR] 1.75, 95% CI 1.42-2.16, p < 0.001), rape (OR 1.95, 95% CI 1.63-2.36, p < 0.001), and depressive symptoms (OR 1.30, 95% CI 1.12-1.52, p < 0.001). Transgender women were more likely to report condomless receptive anal sex in the prior 12 months (OR 2.44, 95% CI 2.05-2.90, p < 0.001) and to be currently living with HIV (OR 1.81, 95% CI 1.49-2.19, p < 0.001). Overall HIV prevalence was 25% (235/926) in transgender women and 14% (505/3,594) in cis-MSM. When adjusted for age, condomless receptive anal sex, depression, interpersonal stigma, law enforcement stigma, and violence, and the interaction of gender with condomless receptive anal sex, the odds of HIV infection for transgender women were 2.2 times greater than the odds for cis-MSM (95% CI 1.65-2.87, p < 0.001). Limitations of the study included sampling strategies tailored for cis-MSM and merging of datasets with non-identical survey instruments.

CONCLUSIONS

In this study in sub-Saharan Africa, we found that HIV burden and stigma differed between transgender women and cis-MSM, indicating a need to address gender diversity within HIV research and programs.

Detection and treatment of Fiebig stage I HIV-1 infection in young at-risk women in South Africa: a prospective cohort study

BACKGROUND

HIV incidence among young women in sub-Saharan Africa remains high and their inclusion in vaccine and cure efforts is crucial. We aimed to establish a cohort of young women detected during Fiebig stage I acute HIV infection in whom treatment was initiated immediately after diagnosis to advance research in this high-risk group.

METHODS

945 women aged 18-23 years in KwaZulu-Natal, South Africa, who were HIV uninfected and sexually active consented to HIV-1 RNA testing twice a week and biological sampling and risk assessment every 3 months during participation in a 48-96 week life-skills and job-readiness programme. We analysed the effect of immediate combination antiretroviral therapy (ART) on viraemia and immune responses, sexual risk behaviour, and the effect of the socioeconomic intervention.

FINDINGS

42 women were diagnosed with acute HIV infection between Dec 1, 2012, and June 30, 2016, (incidence 8·2 per 100 person-years, 95% CI 5·9-11·1), of whom 36 (86%) were diagnosed in Fiebig stage I infection with a median initial viral load of 2·97 log₁₀ copies per mL (IQR 2·42-3·85). 23 of these 36 women started ART at a median of 1 day (1-1) after detection, which limited the median peak viral load to 4·22 log₁₀ copies per mL (3·27-4·83) and the CD4 nadir to 685 cells per μL (561-802). ART also suppressed viral load (to <20 copies per mL) within a median of 16 days (12-26) and, in 20 (87%) of 23 women, prevented seroconversion, as shown with western blotting. 385 women completed the 48 week socioeconomic intervention, of whom 231 were followed up for 1 year. 202 (87%) of these 231 women were placed in jobs, returned to school, or started a business.

INTERPRETATION

Frequent HIV screening combined with a socioeconomic intervention facilitated sampling and risk assessment before and after infection. In addition to detection of acute infection and immediate treatment, we established a cohort optimised for prevention and cure research.

FUNDING

Bill & Melinda Gates Foundation, National Institute of Allergy and Infectious Diseases, International AIDS Vaccine Initiative, Wellcome Trust, Howard Hughes Medical Institute.

[Comparative study of community acute kidney injury in HIV infected versus non-infected persons: Experience of an internal medicine department in Abidjan (Côte d'Ivoire)]

BACKGROUND

Acute kidney injury (AKI) is commonly associated with HIV infection.

OBJECTIVES

To describe the profile of AKI in HIV infected versus non-infected persons.

PATIENTS AND METHODS

This is a prospective study that was carried out during the study period from January 2010 to December 2015 in the department of nephrology-internal medicine D of Treichville University Hospital (Côte d'Ivoire).

RESULTS

The prevalence of HIV infection was 35.2% in the population of AKI. The average age of patients was 42±18 years in the HIV positive group against 51±18 years in the HIV negative group (P=0.0001). Etiologies were infections in 65.1% in the HIV positive group against 38.8% in the HIV negative group (P=0.0001) and water loss in 24.7% in the HIV positive group against 7.8% in the HIV negative group (P=0.0001). Factors such as the AIDS stage (P=0.002), severe sepsis (P=0.002) and acute pyelonephritis (P=0.001) were associated with mortality in HIV positive patients against severe anemia (P=0.0001) and severe sepsis (P=0.0001) in the HIV-negative group.

CONCLUSION

HIV positive patients are younger with a female predominance. The mortality rate is identical in both groups.

Same day ART initiation versus clinic-based pre-ART assessment and counselling for individuals newly tested HIV-positive during community-based HIV testing in rural Lesotho - a randomized controlled trial (CASCADE trial)

BACKGROUND

Achievement of the UNAIDS 90-90-90 targets in Sub-Sahara Africa is challenged by a weak care-cascade with poor linkage to care and retention in care. Community-based HIV testing and counselling (HTC) is widely used in African countries. However, rates of linkage to care and initiation of antiretroviral therapy (ART) in individuals who tested HIV-positive are often very low. A frequently cited reason for non-linkage to care is the time-consuming pre-ART assessment often requiring several clinic visits before ART-initiation.

METHODS

This two-armed open-label randomized controlled trial compares in individuals tested HIV-positive during community-based HTC the proposition of same-day community-based ART-initiation to the standard of care pre-ART assessment at the clinic. Home-based HTC campaigns will be conducted in catchment areas of six clinics in rural Lesotho. Households where at least one individual tested HIV positive will be randomized. In the standard of care group individuals receive post-test counselling and referral to the nearest clinic for pre-ART assessment and counselling. Once they have started ART the follow-up schedule foresees monthly clinic visits. Individuals randomized to the intervention group receive on the spot point-of-care pre-ART assessment and adherence counselling with the proposition to start ART that same day. Once they have started ART, follow-up clinic visits will be less frequent. First primary outcome is linkage to care (individual presents at the clinic at least once within 3 months after the HIV test). The second primary outcome is viral suppression 12 months after enrolment in the study. We plan to enrol a minimum of 260 households with 1:1 allocation and parallel assignment into both arms.

DISCUSSION

This trial will show if in individuals tested HIV-positive during community-based HTC campaigns the proposition of same-day ART initiation in the community, combined with less frequent follow-up visits at the clinic could be a pragmatic approach to improve the care cascade in similar settings.

TRIAL REGISTRATION

NCT02692027 , registered February 21, 2016.

Innovative Strategies for Scale up of Effective Combination HIV Prevention Interventions in Sub-Saharan Africa

For the last three decades, sub-Saharan Africa has been the epicentre of the HIV epidemic. Some key drivers of the epidemic are specific to this region and there is an urgent need to develop context-specific strategies to reduce HIV-related burden. Implementation frameworks should endeavour to combine structural, behavioural and biomedical interventions and the future of the HIV response involves embracing different approaches for different populations; it is not 'one-size fits all approach'. Expanded use of community-based interventions will be key in expanding the role of antiretroviral treatment as prevention (TasP) in the region. For TasP to be effective, high antiretroviral therapy (ART) coverage rates need to be attained. Data from programmatic trials currently underway will provide crucial data to guide the future implementation of TasP.

Magnitude and Kinetics of CD8+ T Cell Activation during Hyperacute HIV Infection Impact Viral Set Point

CD8(+) T cells contribute to the control of HIV, but it is not clear whether initial immune responses modulate the viral set point. We screened high-risk uninfected women twice a week for plasma HIV RNA and identified 12 hyperacute infections. Onset of viremia elicited a massive HIV-specific CD8(+) T cell response, with limited bystander activation of non-HIV memory CD8(+) T cells. HIV-specific CD8(+) T cells secreted little interferon-γ, underwent rapid apoptosis, and failed to upregulate the interleukin-7 receptor, known to be important for T cell survival. The rapidity to peak CD8(+) T cell activation and the absolute magnitude of activation induced by the exponential rise in viremia were inversely correlated with set point viremia. These data indicate that rapid, high magnitude HIV-induced CD8(+) T cell responses are crucial for subsequent immune control of acute infection, which has important implications for HIV vaccine design.

Estimated age and gender profile of individuals missed by a home-based HIV testing and counselling campaign in a Botswana community

INTRODUCTION

It would be useful to understand which populations are not reached by home-based HIV-1 testing and counselling (HTC) to improve strategies aimed at linking these individuals to care and reducing rates of onward HIV transmission.

METHODS

We present the results of a baseline home-based HTC (HBHTC) campaign aimed at counselling and testing residents aged 16 to 64 for HIV in the north-eastern sector of Mochudi, a community in Botswana with about 44,000 inhabitants. Collected data were compared with population references for Botswana, the United Nations (UN) estimates based on the National Census data and the Botswana AIDS Impact Survey IV (BAIS-IV). Analyzed data and references were stratified by age and gender.

RESULTS

A total of 6238 age-eligible residents were tested for HIV-1; 1247 (20.0%; 95% CI 19.0 to 21.0%) were found to be HIV positive (23.7% of women vs. 13.4% of men). HIV-1 prevalence peaked at 44% in 35- to 39-year-old women and 32% in 40- to 44-year-old men. A lower HIV prevalence rate, 10.9% (95% CI 9.5 to 12.5%), was found among individuals tested for the first time. A significant gender gap was evident in all analyzed subsets. The existing HIV transmission network was analyzed by combining phylogenetic mapping and household structure. Between 62.4 and 71.8% of all HIV-positive individuals had detectable virus. When compared with the UN and BAIS-IV estimates, the proportion of men missed by the testing campaign (48.5%; 95% CI 47.0 to 50.0%) was significantly higher than the proportion of missed women (14.2%; 95% CI 13.2 to 15.3%; p<0.0001). The estimated proportion of missed men peaked at about 60% in the age group 30 to 39 years old. The proportions of missed women were substantially smaller, at approximately 28% within the age groups 30 to 34 and 45 to 49 years old.

CONCLUSIONS

The HBHTC campaign seems to be an efficient tool for reaching individuals who have never been tested previously in southern African communities. However, about half of men from 16 to 64 years old were not reached by the HBHTC, including about 60% of men between 30 and 40 years old. Alternative HTC strategies should be developed to bring these men to care, which will contribute to reduction of HIV incidence in communities.

Global HIV epidemiology: A guide for strategies in prevention and care

Global trends in HIV incidence are estimated typically by serial prevalence surveys in selected sentinel populations or less often in representative population samples. Incidence estimates are often modeled because cohorts are costly to maintain and are rarely representative of larger populations. From global trends, we can see reason for cautious optimism. Downward trends in generalized epidemics in Africa, concentrated epidemics in persons who inject drugs (PWID), some female sex worker cohorts, and among older men who have sex with men (MSM) have been noted. However, younger MSM and those from minority populations, as with black MSM in the United States, show continued transmission at high rates. Among the many HIV prevention strategies, current efforts to expand testing, linkage to effective care, and adherence to antiretroviral therapy are known as "treatment as prevention" (TasP). A concept first forged for the prevention of mother to child transmission, TasP generates high hopes that persons treated early will derive considerable clinical benefits and that lower infectiousness will reduce transmission in communities. With the global successes of risk reduction for PWID, we have learned that reducing marginalization of the at-risk population, implementation of nonjudgmental and pragmatic sterile needle and syringe exchange programs, and offering of opiate substitution therapy to help persons eschew needle use altogether can work to reduce the HIV epidemic. Never has the urgency of stigma reduction and guarantees of human rights been more urgent; a public health approach to at-risk populations requires that to avail themselves of prevention services and they must feel welcomed.