BACKGROUND: Respondent-driven sampling (RDS) is the current standard for sampling key populations at risk for HIV infections but is usually limited to local implementation in single towns or cities. Web-based sampling eliminates this spatial constraint but often relies on self-selected convenience samples. We piloted a web-based RDS survey with biomarker collection among men who have sex with men (MSM) in Thailand. OBJECTIVE: This study aimed to evaluate and demonstrate the feasibility of implementing a web-based RDS survey as a routine surveillance system in Thailand. The goal was to enhance surveillance efforts targeting hard-to-reach populations in the country. METHODS: We developed a website to fully function like a conventional RDS survey office, including coupon verification, eligibility screening, consenting, interviewing (self-administered), peer recruitment training, coupon issuance, compensation, and recruitment tracking. All functions were automated; data managers monitored recruitment, data collection, and payment and could be contacted by recruits as needed. Eligible participants were male, older than 15 years, resided in Thailand, and had anal sex with a man in the past 6 months. Recruits who resided in Bangkok were additionally invited to physically attend a participating health clinic of their choice for an HIV-related blood draw. Data were weighted to account for the complex sampling design. RESULTS: The survey was implemented from February to June 2022; seeds (21 at start, 14 added later) were identified mostly through targeted web-based banner ads; coupon uptake was 45.1%. Of 2578 candidate recruits screened for eligibility, 2151 (83.4%) were eligible and 2142 (83.1%) enrolled. Almost all (2067/2578, 80.2%) completed the questionnaire; however, 318 survey records were removed from analysis as fraudulent enrollments. The final sample size was 1749, the maximum number of waves achieved was 191, and sampling covered all 6 geographic regions and 75 of 77 (97.4%) provinces; convergence was reached for several salient variables. The mean age was 20.5 (SD 4.0) years, and most (69.8%) had never tested for HIV before, with fear of stigma as the biggest reason (97.1%) for not having tested. Most (76.9%) had visited gay-focused physical venues several times a week. A condom was used in 97.6% of the last sex acts, 11.0% had purchased sex from other men (past 12 mo), 4.5% had sold sex to men (past 12 mo), and 95.3% had 3+ male sex partners (last 3 mo). No participant in Bangkok presented for a blood draw. CONCLUSIONS: We successfully conducted a web-based RDS survey among MSM in Thailand, covering nearly the entire country, although, as in physical RDS surveys, sampling was dominated by younger MSM. The survey also failed to collect biomarkers in Bangkok. Public health interventions should aim at increasing testing and addressing (the perception of) stigma.

BACKGROUND: Thailand's HIV epidemic is heavily concentrated among men who have sex with men (MSM), and surveillance efforts are mostly based on case surveillance and local biobehavioral surveys. OBJECTIVE: We piloted Kai Noi, a web-based respondent-driven sampling (RDS) survey among MSM. METHODS: We developed an application coded in PHP that facilitated all procedures and events typically used in an RDS office for use on the web, including e-coupon validation, eligibility screening, consent, interview, peer recruitment, e-coupon issuance, and compensation. All procedures were automated and e-coupon ID numbers were randomly generated. Participants' phone numbers were the principal means to detect and prevent duplicate enrollment. Sampling took place across Thailand; residents of Bangkok were also invited to attend 1 of 10 clinics for an HIV-related blood draw with additional compensation. RESULTS: Sampling took place from February to June 2022; seeds (21 at the start, 14 added later) were identified through banner ads, micromessaging, and in online chat rooms. Sampling reached all 6 regions and almost all provinces. Fraudulent (duplicate) enrollment using "borrowed" phone numbers was identified and led to the detection and invalidation of 318 survey records. A further 106 participants did not pass an attention filter question (asking recruits to select a specific categorical response) and were excluded from data analysis, leading to a final data set of 1643 valid participants. Only one record showed signs of straightlining (identical adjacent responses). None of the Bangkok respondents presented for a blood draw. CONCLUSIONS: We successfully developed an application to implement web-based RDS among MSM across Thailand. Measures to minimize, detect, and eliminate fraudulent survey enrollment are imperative in web-based surveys offering compensation. Efforts to improve biomarker uptake are needed to fully tap the potential of web-based sampling and data collection.

We conducted a population-based survey in 2013 in Kampala, Uganda, to examine violence and mental health outcomes among self-settled male refugees from the Eastern Democratic Republic of Congo (DRC). Male DRC refugees aged 18+ years were sampled through respondent-driven sampling. Key interview domains included demographics, experiences of sexual and nonsexual violence, social support, PTSD, depression and suicide ideation. Data analysis was weighted to generate population-level estimates. We sampled 718 men (mean age: 33 years), most of whom had lived in North or South Kivu. Nonsexual violence, such as beatings (79.4%) and torture (63.8%), was frequent. A quarter (26.2%) had been raped; 49.9% of rape victims had been raped on multiple occasions, and 75.7% of rape victims had been gang raped. We estimated 52.8% had post-traumatic stress disorder (PTSD); 44.4% reported suicidal ideation. Numerous traumas were significantly (p < 0.05) associated with PTSD such as rape (adjusted odds ratio [aOR] = 1.82), war-related injuries (aOR = 2.90) or having been exposed to >15 traumas (compared to ≤10; aOR = 6.89). Traumata are frequent experiences in this self-settled male refugee population and are often accompanied by adverse mental health outcomes. Screening for trauma and adverse mental health outcomes and providing targeted services are paramount to improve these refugees' lives.

BACKGROUND: Key population HIV programmes in sub-Saharan Africa require epidemiological information to ensure equitable and universal access to effective services. We aimed to consolidate and harmonise survey data among female sex workers, men who have sex with men, people who inject drugs, and transgender people to estimate key population size, HIV prevalence, and antiretroviral therapy (ART) coverage for countries in mainland sub-Saharan Africa. METHODS: Key population size estimates, HIV prevalence, and ART coverage data from 39 sub-Saharan Africa countries between 2010 and 2023 were collated from existing databases and verified against source documents. We used Bayesian mixed-effects spatial regression to model urban key population size estimates as a proportion of the gender-matched, year-matched, and area-matched population aged 15-49 years. We modelled subnational key population HIV prevalence and ART coverage with age-matched, gender-matched, year-matched, and province-matched total population estimates as predictors. FINDINGS: We extracted 2065 key population size data points, 1183 HIV prevalence data points, and 259 ART coverage data points. Across national urban populations, a median of 1·65% (IQR 1·35-1·91) of adult cisgender women were female sex workers, 0·89% (0·77-0·95) were men who have sex with men, 0·32% (0·31-0·34) were men who injected drugs, and 0·10% (0·06-0·12) were women who were transgender. HIV prevalence among key populations was, on average, four to six times higher than matched total population prevalence, and ART coverage was correlated with, but lower than, the total population ART coverage with wide heterogeneity in relative ART coverage across studies. Across sub-Saharan Africa, key populations were estimated as comprising 1·2% (95% credible interval 0·9-1·6) of the total population aged 15-49 years but 6·1% (4·5-8·2) of people living with HIV. INTERPRETATION: Key populations in sub-Saharan Africa experience higher HIV prevalence and lower ART coverage, underscoring the need for focused prevention and treatment services. In 2024, limited data availability and heterogeneity constrain precise estimates for programming and monitoring trends. Strengthening key population surveys and routine data within national HIV strategic information systems would support more precise estimates. FUNDING: UNAIDS, Bill & Melinda Gates Foundation, and US National Institutes of Health.

Tenofovir disoproxil fumarate and emtricitabine are used for HIV treatment and pre-exposure prophylaxis. Previously, we found that topical rectal application of tenofovir 1% gel caused many gene expression changes. Here, we measured RNA and protein expression in several clinical trials of oral administration in HIV-uninfected individuals (using microarrays, RNAseq, droplet digital PCR, mass spectrometry, and microscopy). We found tens to hundreds of differentially expressed genes in the gastrointestinal tract, but none in the blood or female reproductive tract. In rectal samples from one trial, most of the 13 upregulated genes were related to type I/III interferon signaling. Similar changes were seen at the protein level in the same trial and in the duodenum and rectum in another trial. We conclude that tenofovir disoproxil fumarate and emtricitabine have little effect on gene expression in the blood or female reproductive tract but increase type I/III interferon signaling in the gut. This effect may enhance their anti-viral efficacy when used as pre-exposure prophylaxis, in particular to prevent rectal HIV transmission. However, it may also contribute to chronic immune activation and HIV reservoir maintenance in chronically treated people living with HIV.

Background: HIV programmes in sub-Saharan Africa (SSA) require information about HIV among key populations to ensure equitable and equal access to HIV prevention and treatment. Surveillance has been conducted among female sex workers (FSW), men who have sex with men (MSM), people who inject drugs (PWID), and transgender populations, but is not systematically included in national HIV estimates. We consolidated existing KP surveys to create national-level estimates of key population size, HIV prevalence, and ART coverage for mainland SSA. Method(s): Key population size estimates (KPSE), HIV prevalence, and ART coverage data from 38 countries from 2010-2021 were collated from existing databases, deduplicated, and verified against primary sources. We used Bayesian mixed-effects regression to spatially smooth KPSE, and regressed subnational key population HIV prevalence and ART coverage against age/sex/year/province-matched total population estimates. Finding(s): We extracted 1449 unique KPSE datapoints, 1181 HIV prevalence datapoints, and 242 ART coverage datapoints. Countries had data for a median of five of the twelve population/outcome stratifications. Across countries, a median of 1.44% of urban women were FSW (interquartile range [IQR] 0.83-1.89%); 0.60% of urban men were MSM; and 0.16% of urban adults injected drugs (IQR 0.14-0.24%). HIV prevalence in all key populations was higher than matched total population prevalence. ART coverage was correlated with, but lower than, total population ART coverage. Across SSA, key populations were estimated as 1.1% (95%CI 0.7-1.9%) of the population but 5.1% (95%CI 3.2-10.3%) of all PLHIV aged 15-49 years. Interpretation(s): Key populations in sub-Saharan experience disproportionate HIV burden and somewhat lower ART coverage, underscoring need for focused prevention and treatment services. However, large heterogeneity and incomplete data availability limit precise estimates for programming and monitoring trends. Future efforts should focus on integrating and strengthening key population surveys and routine data within national HIV strategic information systems. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license.

BACKGROUND: We examined the epidemiology and transmission potential of HIV population viral load (VL) in 12 sub-Saharan African countries. METHODS: We analyzed data from Population-based HIV Impact Assessments (PHIAs), large national household-based surveys conducted between 2015 and 2019 in Cameroon, Cote d'Ivoire, Eswatini, Kenya, Lesotho, Malawi, Namibia, Rwanda, Tanzania, Uganda, Zambia, and Zimbabwe. Blood-based biomarkers included HIV serology, recency of HIV infection, and VL. We estimated the number of people living with HIV (PLHIV) with suppressed viral load (<1,000 HIV-1 RNA copies/mL) and with unsuppressed viral load (viremic), the prevalence of unsuppressed HIV (population viremia), sex-specific HIV transmission ratios (number female incident HIV-1 infections/number unsuppressed male PLHIV per 100 persons-years [PY] and vice versa) and examined correlations between a variety of VL metrics and incident HIV. Country sample sizes ranged from 10,016 (Eswatini) to 30,637 (Rwanda); estimates were weighted and restricted to participants 15 years and older. RESULTS: The proportion of female PLHIV with viral suppression was higher than that among males in all countries, however, the number of unsuppressed females outnumbered that of unsuppressed males in all countries due to higher overall female HIV prevalence, with ratios ranging from 1.08 to 2.10 (median: 1.43). The spatial distribution of HIV seroprevalence, viremia prevalence, and number of unsuppressed adults often differed substantially within the same countries. The 1% and 5% of PLHIV with the highest VL on average accounted for 34% and 66%, respectively, of countries' total VL. HIV transmission ratios varied widely across countries and were higher for male-to-female (range: 2.3-28.3/100 PY) than for female-to-male transmission (range: 1.5-10.6/100 PY). In all countries mean log10 VL among unsuppressed males was higher than that among females. Correlations between VL measures and incident HIV varied, were weaker for VL metrics among females compared to males and were strongest for the number of unsuppressed PLHIV per 100 HIV-negative adults (R2 = 0.92). CONCLUSIONS: Despite higher proportions of viral suppression, female unsuppressed PLHIV outnumbered males in all countries examined. Unsuppressed male PLHIV have consistently higher VL and a higher risk of transmitting HIV than females. Just 5% of PLHIV account for almost two-thirds of countries' total VL. Population-level VL metrics help monitor the epidemic and highlight key programmatic gaps in these African countries.

BACKGROUND: Estimating HIV-1 incidence using biomarker assays in cross-sectional surveys is important for understanding the HIV pandemic. However, the utility of these estimates has been limited by uncertainty about what input parameters to use for false recency rate (FRR) and mean duration of recent infection (MDRI) after applying a recent infection testing algorithm (RITA). METHODS: This article shows how testing and diagnosis reduce both FRR and mean duration of recent infection compared to a treatment-naive population. A new method is proposed for calculating appropriate context-specific estimates of FRR and mean duration of recent infection. The result of this is a new formula for incidence that depends only on reference FRR and mean duration of recent infection parameters derived in an undiagnosed, treatment-naive, nonelite controller, non-AIDS-progressed population. RESULTS: Applying the methodology to eleven cross-sectional surveys in Africa results in good agreement with previous incidence estimates, except in 2 countries with very high reported testing rates. CONCLUSIONS: Incidence estimation equations can be adapted to account for the dynamics of treatment and recent infection testing algorithms. This provides a rigorous mathematical foundation for the application of HIV recency assays in cross-sectional surveys.

BACKGROUND: Female sex workers are vulnerable to HIV, sexually transmitted diseases, and unintended pregnancies; however, the literature on female sex workers (FSW) focuses primarily on HIV and is limited regarding these other health issues. METHODS: We conducted a respondent-driven sampling (RDS) survey during April-December 2012 to characterize the reproductive health of and access to contraceptives FSW in Kampala, Uganda. Eligibility criteria included age15years, residence in greater Kampala, and having sold sex to men in6months. Data were analyzed using RDS-Analyst. Survey logistic regression was used in SAS. RESULTS: We enrolled 1,497 FSW with a median age of 27years. Almost all FSW had been pregnant at least once. An estimated 33.8% of FSW were currently not using any form of family planning (FP) to prevent pregnancy; 52.7% used at least moderately effective FP. Among those using FP methods, injectable contraception was the most common form of FP used (55.4%), followed by condoms (19.7%), oral contraception (18.1%), and implants (3.7%). HIV prevalence was 31.4%, syphilis prevalence was 6.2%, and 89.8% had at least one symptom of a sexually transmitted disease in the last six months. Using at least a moderately effective method of FP was associated with accessing sexually transmitted disease treatment in a stigma-free environment in the last six months (aOR: 1.6, 95% CI: 1.1-2.4), giving birth to 2-3 children (aOR: 2.5, 95% CI: 1.4-4.8) or 4-5 children (aOR: 2.9, 95% CI: 1.4-5.9). It is plausible that those living with HIV are also less likely than those without it to be using a moderately effective method of FP (aOR: 0.7, 95% CI: 0.5-1.0). CONCLUSIONS: The provision of integrated HIV and sexual and reproductive health services in a non-stigmatizing environment has the potential to facilitate increased health service uptake by FSW and decrease missed opportunities for service provision.

Upon request from tribal nations, and as part of the Centers for Disease Control and Prevention's (CDC's) emergency response, CDC staff provided both remote and on-site assistance to tribes to plan, prepare, and respond to the COVID-19 pandemic. From April 2, 2020, through June 11, 2021, CDC deployed a total of 275 staff to assist 29 tribal nations. CDC staff typically collaborated in multiple work areas including epidemiology and surveillance (86%), contact tracing (76%), infection prevention control (72%), community mitigation (72%), health communication (66%), incident command structure (55%), emergency preparedness (38%), and worker safety (31%). We describe the activities of CDC staff in collaboration with 4 tribal nations, Northern Cheyenne, Hoopa Valley, Shoshone-Bannock, and Oglala Sioux Tribe, to combat COVID-19 and lessons learned from the engagement.

BACKGROUND: Population size estimates (PSE) provide critical information in determining resource allocation for HIV services geared toward those at high risk of HIV, including female sex workers, men who have sex with men, and people who inject drugs. Capture-recapture (CRC) is often used to estimate the size of these often-hidden populations. Compared with the commonly used 2-source CRC, CRC relying on 3 (or more) samples (3S-CRC) can provide more robust PSE but involve far more complex statistical analysis. OBJECTIVE: This study aims to design and describe the Shiny application (shinyrecap), a user-friendly interface that can be used by field epidemiologists to produce PSE. METHODS: shinyrecap is built on the Shiny web application framework for R. This allows it to seamlessly integrate with the sophisticated CRC statistical packages (eg, Rcapture, dga, LCMCR). Additionally, the application may be accessed online or run locally on the user's machine. RESULTS: The application enables users to engage in sample size calculation based on a simulation framework. It assists in the proper formatting of collected data by providing a tool to convert commonly used formats to that used by the analysis software. A wide variety of methodologies are supported by the analysis tool, including log-linear, Bayesian model averaging, and Bayesian latent class models. For each methodology, diagnostics and model checking interfaces are provided. CONCLUSIONS: Through a use case, we demonstrated the broad utility of this powerful tool with 3S-CRC data to produce PSE for female sex workers in a subnational unit of a country in sub-Saharan Africa.

BACKGROUND: Epidemiologic research among migrant populations is limited by logistical, methodological, and ethical challenges, but it is necessary for informing public health and humanitarian programming. OBJECTIVE: We describe a methodology to estimate HIV prevalence among Venezuelan migrants in Colombia. METHODS: Respondent-driven sampling, a nonprobability sampling method, was selected for attributes of reaching highly networked populations without sampling frames and analytic methods that permit estimation of population parameters. Respondent-driven sampling was modified to permit electronic referral of peers via SMS text messaging and WhatsApp. Participants complete sociobehavioral surveys and rapid HIV and syphilis screening tests with confirmatory testing. HIV treatment is not available for migrants who have entered Colombia through irregular pathways; thus, medicolegal services integrated into posttest counseling provide staff lawyers and legal assistance to participants diagnosed with HIV or syphilis for sustained access to treatment through the national health system. Case finding is integrated into respondent-driven sampling to allow partner referral. This study is implemented by a local community-based organization providing HIV support services and related legal services for Venezuelans in Colombia. RESULTS: Data collection was launched in 4 cities in July and August 2021. As of November 2021, 3105 of the target 6100 participants were enrolled, with enrollment expected to end by February/March 2022. CONCLUSIONS: Tailored methods that combine community-led efforts with innovations in sampling and linkage to care can aid in advancing health research for migrant and displaced populations. Worldwide trends in displacement and migration underscore the value of improved methods for translation to humanitarian and public health programming. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/36026.

Although sub-Saharan Africa has the highest HIV burden globally, few studies have investigated disabilities and HIV in this region. We conducted a secondary analysis of text data from in-depth interviews (2014-2015) to describe HIV perceptions among a subsample of 73 deaf individuals participating in the Crane survey, Kampala, Uganda. Being deaf was defined as being profoundly or functionally deaf, having deafness onset 5 + years ago, and preferring sign language to communicate. Among participants ever tested for HIV (47%), most (88%) had a negative test. Thematic analysis revealed overcoming challenges/barriers followed by socioeconomic status, support systems, HIV, stigma, abuse, and health conditions as major themes. An unanticipated finding was the role of sex work to support basic living needs. The data showed related themes among participants, suggesting a complex context in which deaf participants experience HIV prevention and treatment. It is important to tailor HIV interventions for deaf and disabled persons.

BACKGROUND: The population-based HIV impact assessment (population-based HIV impact assessments) surveys are among the first to estimate national adult HIV incidence, subnational prevalence of viral load suppression, and pediatric HIV prevalence. We summarize the survey methods implemented in Zimbabwe, Malawi, and Zambia, as well as response rates and quality metrics. METHODS: Each cross-sectional, household-based survey used a 2-stage cluster design. Survey preparations included sample design, questionnaire development, tablet programming for informed consent and data collection, community mobilization, establishing a network of satellite laboratories, and fieldworker training. Interviewers collected demographic, behavioral, and clinical information using tablets. Blood was collected for home-based HIV testing and counseling (HBTC) and point-of-care CD4+ T-cell enumeration with results immediately returned. HIV-positive blood samples underwent laboratory-based confirmatory testing, HIV incidence testing, RNA polymerase chain reaction (viral load), DNA polymerase chain reaction (early infant diagnosis), and serum antiretroviral drug detection. Data were weighted for survey design, and chi square automatic interaction detection-based methods were used to adjust for nonresponse. RESULTS: Each survey recruited a nationally representative, household-based sample of children and adults over a 6-10-month period in 2015 and 2016. Most (84%-90%) of the 12,000-14,000 eligible households in each country participated in the survey, with 77%-81% of eligible adults completing an interview and providing blood for HIV testing. Among eligible children, 59%-73% completed HIV testing. Across the 3 surveys, 97.8% of interview data were complete and had no errors. CONCLUSION: Conducting a national population-based HIV impact assessment with immediate return of HIV and other point-of-care test results was feasible, and data quality was high.

BACKGROUND: Violence and traumatic events are highly prevalent among refugees, but less is known about the impact of these experiences among self-settled refugees in the country of asylum. We evaluated the association between traumatic experiences and PTSD and depression symptoms among female Democratic Republic of Congo (DRC) refugees living in Kampala, Uganda. METHODS: Participants were recruited using respondent driven sampling in one refugee service center in Kampala, Uganda. Eligibility criteria included: Congolese nationality, age 18+ years, self-settled in Kampala for at least 6 months, refugee status or documentation of application for refugee status. Only data from female participants were included in this analysis. Depression symptoms were screened with the Patient Health Questionnaire-2, and symptom criteria for PTSD and traumatic experiences were evaluated with the Harvard Trauma Questionnaire. Logistic regression models were performed to separately assess associations between mental health outcomes (PTSD and depression), rape and non-sexual violence. RESULTS: Five hundred eighty women with a mean age of 33 years were interviewed. Among participants, 73% (95% CI:67-78%) met symptom criteria for PTSD, 57% (95% CI: 51-63%) for depression, and 65% reported thoughts of ending one's life. 79% of women reported experience of rape, for over half (54%) it occurred more than once, and 82% were gang raped. Crude and adjusted odds ratios (ORs) show that PTSD was most strongly associated with being raped (OR = 2.43, p < 0.01), lacking shelter (OR = 2.86, p < 0.01), lacking food or water (OR = 2.53, p = 0.02), lacking access to health care (OR = 2.84, p < 0.01), forced labor (OR = 2.6, p < 0.01), extortion and/or robbery (OR = 3.08, p < 0.01), experiencing the disappearance/kidnapping of a family member or friend (OR = 2.72, p < 0.01), and witnessing the killing or murder of other people (OR = 3.28, p < 0.01). Depression was significantly associated with several traumatic experiences including rape (OR = 2.3, p = 0.01), and experiencing the disappearance/kidnapping of a child or spouse (OR = 1.99, p = 0.01). CONCLUSIONS: Refugee women self-settled in Kampala reported high lifetime experiences of violence and traumatic events including rape, as well as high rates of PTSD and depression. Future programming addressing self-settled refugees and their settlement in host countries may benefit from including local and national integration strategies.

Large public-health training events may result in SARS-CoV-2 transmission. Universal SARS-CoV-2 testing during trainings for the Uganda Population-based HIV Impact Assessment identified 28/475 (5.9%) individuals with COVID-19 among attendees; most (89.3%) were asymptomatic. Effective COVID-19 mitigation measures, along with SARS-CoV-2 testing, are recommended for in-person trainings, particularly when trainees will have subsequent contact with survey participants.

BACKGROUND: HIV population viral load (PVL) can reflect antiretroviral therapy (ART) program effectiveness and transmission potential in a community. Using nationally representative data from household surveys conducted in Zimbabwe, Malawi, and Zambia in 2015-16, we examined the association between various VL measures and the probability of at least one recent HIV-1 infection in the community. METHODS: We used Limiting-antigen (LAg) Avidity enzyme immunoassay (EIA), VLS (HIV RNA <1000 copies/mL), and ARVs in the blood to identify recent HIV-1 cases. RESULTS: Among 1,510 EAs across the three surveys, 52,036 adults aged 15-59 years resided in 1,363 (90.3%) EAs with at least one HIV-positive adult consenting to interview and blood draw and whose VL was tested. Mean HIV prevalence across these EAs was 13.1% (95% confidence intervals [CI] 12.7-13.5). Mean VLS prevalence across these EAs was 58.7% (95% CI 57.3-60.0).In multivariable analysis, PVL was associated with a recent HIV-1 case in that EA (adjusted odds ratio [AOR]: 1.4, 95% CI 1.2-1.6, p=0.001). VLS prevalence was inversely correlated with recent infections (AOR: 0.3, 95% CI 0.1-0.6, p=0.004). The 90-90-90 indicators, namely, the prevalence of HIV diagnosis, ART coverage, and VLS at the EA level, were inversely correlated with HIV recency at the EA level. CONCLUSION: We found a strong association between PVL and VLS prevalence and recent HIV-1 infection at the EA level across three southern African countries with generalized HIV epidemics. These results suggest that population-based measures of VLS in communities may serve as a proxy for epidemic control.

Accurate size estimates of key populations (eg, sex workers, people who inject drugs, transgender people, and men who have sex with men) can help to ensure adequate availability of services to prevent or treat HIV infection; inform HIV response planning, target setting, and resource allocation; and provide data for monitoring and evaluating program outcomes and impact. A gold standard method for population size estimation does not exist, but quality of estimates could be improved by using empirical methods, multiple data sources, and sound statistical concepts. To highlight such methods, a special collection of papers in JMIR Public Health and Surveillance has been released under the title "Key Population Size Estimations." We provide a summary of these papers to highlight advances in the use of empirical methods and call attention to persistent gaps in information.

Tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) are used for HIV treatment and prevention. Previously, we found that topical rectal tenofovir gel caused immunological changes in the mucosa. Here, we assess the effect of oral TDF/FTC in three HIV pre-exposure prophylaxis trials, two with gastrointestinal and one with cervicovaginal biopsies. TDF/FTC induces type I/III interferon-related (IFN I/III) genes in the gastrointestinal tract, but not blood, with strong correlations between the two independent rectal biopsy groups (Spearman r = 0.91) and between the rectum and duodenum (r = 0.81). Gene set testing also indicates stimulation of the type I/III pathways in the ectocervix and of cellular proliferation in the duodenum. mRNA sequencing, digital droplet PCR, proteomics, and immunofluorescence confirm IFN I/III pathway stimulation in the gastrointestinal tract. Thus, oral TDF/FTC stimulates an IFN I/III signature throughout the gut, which could increase antiviral efficacy but also cause chronic immune activation in HIV prevention and treatment settings.

Respondent-driven sampling (RDS) is commonly used to sample from key populations without a sampling frame since traditional methods are unable to efficiently survey them. Surveying these populations is often desirable to inform service delivery, assess effectiveness of programs, and determine prevalence of diseases. However, there are concerns about how RDS works in practice due to its many assumptions. To assess some of these assumptions, we develop diagnostics using geographical data and demonstrate their utility by identifying lack of convergence and characterizing RDS reach in surveys conducted among female sex workers and men who have sex with men in Kampala, Uganda.

In sub-Saharan Africa, men who have sex with men (MSM) are socially, largely hidden and face disproportionate risk for HIV infection. Attention to HIV epidemics among MSM in Uganda and elsewhere in sub-Saharan Africa has been obscured by repressive governmental policies, criminalisation, stigma and the lack of basic epidemiological data describing these epidemics. In this paper, we aim to explore healthcare access, experiences with HIV prevention services and structural barriers to using healthcare services in order to inform the acceptability of a combination HIV prevention package of services for men who have sex with men in Uganda. We held focus group discussions (FGDs) with both MSM and healthcare providers in Kampala, Uganda, to explore access to services and to inform prevention and care. Participants were recruited through theoretical sampling with criteria based on ability to answer the research questions. Descriptive thematic coding was used to analyse the FGD data. We described MSM experiences, both negative and positive, as they engaged with health services. Our findings showed that socio-structural factors, mediated by psychological and relational factors impacted MSM engagement in care. The socio-structural factors such as stigma, homophobia and policy issues emerged strongly as did the mediating factors such as relations with specific health staff and a social support structure. A combination intervention addressing structural, social and psychological barriers could have an impact even in the precarious policy environment where this study was conducted.

BACKGROUND: Key populations, including people who inject drugs (PWID), men who have sex with men (MSM), and female sex workers (FSW), are disproportionately affected by the HIV epidemic. Understanding the magnitude of, and informing the public health response to, the HIV epidemic among these populations requires accurate size estimates. However, low social visibility poses challenges to these efforts. OBJECTIVE: The objective of this study was to derive population size estimates of PWID, MSM, and FSW in Kampala using capture-recapture. METHODS: Between June and October 2017, unique objects were distributed to the PWID, MSM, and FSW populations in Kampala. PWID, MSM, and FSW were each sampled during 3 independent captures; unique objects were offered in captures 1 and 2. PWID, MSM, and FSW sampled during captures 2 and 3 were asked if they had received either or both of the distributed objects. All captures were completed 1 week apart. The numbers of PWID, MSM, and FSW receiving one or both objects were determined. Population size estimates were derived using the Lincoln-Petersen method for 2-source capture-recapture (PWID) and Bayesian nonparametric latent-class model for 3-source capture-recapture (MSM and FSW). RESULTS: We sampled 467 PWID in capture 1 and 450 in capture 2; a total of 54 PWID were captured in both. We sampled 542, 574, and 598 MSM in captures 1, 2, and 3, respectively. There were 70 recaptures between captures 1 and 2, 103 recaptures between captures 2 and 3, and 155 recaptures between captures 1 and 3. There were 57 MSM captured in all 3 captures. We sampled 962, 965, and 1417 FSW in captures 1, 2, and 3, respectively. There were 316 recaptures between captures 1 and 2, 214 recaptures between captures 2 and 3, and 235 recaptures between captures 1 and 3. There were 109 FSW captured in all 3 rounds. The estimated number of PWID was 3892 (3090-5126), the estimated number of MSM was 14,019 (95% credible interval (CI) 4995-40,949), and the estimated number of FSW was 8848 (95% CI 6337-17,470). CONCLUSIONS: Our population size estimates for PWID, MSM, and FSW in Kampala provide critical population denominator data to inform HIV prevention and treatment programs. The 3-source capture-recapture is a feasible method to advance key population size estimation.

OBJECTIVES: Achieving the Sustainable Development Goals will require data-driven public health action. There are limited publications on national health information systems that continuously generate health data. Given the need to develop these systems, we summarised their current status in low-income and middle-income countries. SETTING: The survey team jointly developed a questionnaire covering policy, planning, legislation and organisation of case reporting, patient monitoring and civil registration and vital statistics (CRVS) systems. From January until May 2017, we administered the questionnaire to key informants in 51 Centers for Disease Control country offices. Countries were aggregated for descriptive analyses in Microsoft Excel. RESULTS: Key informants in 15 countries responded to the questionnaire. Several key informants did not answer all questions, leading to different denominators across questions. The Ministry of Health coordinated case reporting, patient monitoring and CRVS systems in 93% (14/15), 93% (13/14) and 53% (8/15) of responding countries, respectively. Domestic financing supported case reporting, patient monitoring and CRVS systems in 86% (12/14), 75% (9/12) and 92% (11/12) of responding countries, respectively. The most common uses for system-generated data were to guide programme response in 100% (15/15) of countries for case reporting, to calculate service coverage in 92% (12/13) of countries for patient monitoring and to estimate the national burden of disease in 83% (10/12) of countries for CRVS. Systems with an electronic component were being used for case reporting, patient monitoring, birth registration and death registration in 87% (13/15), 92% (11/12), 77% (10/13) and 64% (7/11) of responding countries, respectively. CONCLUSIONS: Most responding countries have a solid foundation for policy, planning, legislation and organisation of health information systems. Further evaluation is needed to assess the quality of data generated from systems. Periodic evaluations may be useful in monitoring progress in strengthening and harmonising these systems over time.

BACKGROUND: Key populations at higher risk for HIV infection, including people who inject drugs, men who have sex with men (MSM), and female sex workers (FSWs), are disproportionately affected by the HIV/AIDS epidemic. Empirical estimates of their population sizes are necessary for HIV program planning and monitoring. Such estimates, however, are lacking for most of Uganda's urban centers. OBJECTIVE: The aim of this study was to estimate the number of FSWs and MSM in select locations in Uganda. METHODS: We utilized conventional 2-source capture-recapture (CRC) to estimate the population of FSWs in Mbale, Jinja, Wakiso, Mbarara, Gulu, Kabarole, Busia, Tororo, Masaka, and Kabale and the population of MSM in Mbale, Jinja, Wakiso, Mbarara, Gulu, Kabarole, and Mukono from June to August 2017. Hand mirrors and key chains were distributed to FSWs and MSM, respectively, by peers during capture 1. A week later, different FSWs and MSM distributors went to the same towns to collect data for the second capture. Population size estimates and 95% CIs were calculated using the CRC Simple Interactive Statistical Analysis. RESULTS: We estimated the population of FSWs and MSM using 2 different recapture definitions: those who could present the object or identify the object from a set of photos. The most credible (closer to global estimates of MSM; 3%-5%) estimates came from those who presented the objects only. The FSW population in Mbale was estimated to be 693 (95% CI 474-912). For Jinja, Mukono, Busia, and Tororo, we estimated the number of FSWs to be 802 (95% CI 534-1069), 322 (95% CI 300-343), 961 (95% CI 592-1330), and 2872 (95% CI 0-6005), respectively. For Masaka, Mbarara, Kabale, and Wakiso, we estimated the FSWs population to be 512 (95% CI 384-639), 1904 (95% CI 1058-2749), 377 (95% CI 247-506), and 828 (95% CI 502-1152), respectively. For Kabarole and Gulu, we estimated the FSWs population to be 397 (95% CI 325-469) and 1425 (95% CI 893-1958), respectively. MSM estimates were 381 (95% CI 299-462) for Mbale, 1100 (95% CI 351-1849) for Jinja, 368 (95% CI 281-455) for Wakiso, 322 (95% CI 253-390) for Mbarara, 180 (95% CI 170-189) for Gulu, 335 (95% CI 258-412) for Kabarole, and 264 (95% CI 228-301) for Mukono. CONCLUSIONS: The CRC activity was one of the first to be carried out in Uganda to obtain small town-level population sizes for FSWs and MSM. We found that it is feasible to use FSW and MSM peers for this activity, but proper training and standardized data collection tools are essential to minimize bias.

BACKGROUND: Some observational studies have found increased HIV risk associated with self-reported use of injectable depot medroxyprogesterone acetate (DMPA). Testing blood samples for MPA, the progestin in DMPA, permits validation of self-reported data and exploration of whether potential HIV risk is correlated with MPA levels, which are highest soon after injection. METHODS: We conducted a case-control study testing archived serum from women who participated in three longitudinal studies of HIV prevention in East and southern Africa. Case samples, from women who acquired HIV, were from visits that occurred at or immediately prior to the first evidence of HIV infection. Secondary analyses restricted to case samples collected within 15 and 30 days of the estimated date of HIV infection. Matched control samples were from women who remained HIV-uninfected. We used multivariable conditional logistic regression to compare exogenous hormone levels, quantified through mass spectrometry, among cases and controls. RESULTS: When restricted to cases with samples collected within </=15 days of estimated date of HIV infection, MPA detection was more frequent among women who acquired HIV (adjusted odds ratio [AOR] = 2.75, 95% confidence interval [CI] 1.22-6.19). In this subset, the increase in HIV risk was only among samples with MPA detected at a low level of 0.02-0.50ng/ml: 36.7% of cases and 9.4% of controls, AOR = 6.03, 95% CI 2.50-14.54. CONCLUSIONS: Detection of MPA at low levels close to the estimated time of HIV acquisition was significantly more frequent among women who acquired HIV. Studies are needed that explore biological mechanisms elicited by any MPA level and HIV risk.

Transgender women in Kampala face stigma, high HIV acquisition or transmission risk and poor access to health services. We explored the HIV and gender-related contexts of their lives. Snowball sampling was used to enrol 45 participants between July-October 2013. Data collection included audio-computer-assisted self-interviews, qualitative face-to-face interviews and blood tests for HIV and CD4. One in five respondents tested HIV positive. Emergent themes revealed highly varied forms of gender identity and gender expression. Almost all respondents asserted that they frequently engaged in sex work, mainly due to lack of employment. HIV-related themes included limited access to non-stigmatising health services, inconsistent condom use, inaccurate perceptions of self and partners' risk, alcohol use, receptive anal sex with men, multiple sex partners, frequent self and enacted stigma, and violence. Findings highlight the urgency of providing members of this marginalised population with tailored, innovative, comprehensive and effective HIV prevention programmes that address structural issues such as access to HIV services and limited employment as well as behavioural issues such as inconsistent condom use, multiple sexual partners, self and enacted stigma, violence and alcohol use.

HIV incidence information is essential for epidemic monitoring and evaluating preventive interventions. However, reliable HIV incidence data is difficult to obtain, especially among marginalized populations, such as young men who have sex with men (YMSM). Here we evaluate the reliability of an alternative HIV incidence assessment method, behavioral imputation, as compared to serologically estimated HIV incidence. Recent HIV incidence among YMSM (aged 18 to 21 and 18 to 24 years) enrolled in a cohort study in Bangkok from 2006 to 2014 was estimated using two mid-point methods for seroconversion: 1) between age of first anal intercourse and first HIV-positive test (without previous HIV-negative test) (behavioral imputation) and 2) between the date of last negative and first positive HIV test (serological estimation). Serologically estimated HIV incidence was taken as the "gold standard" to evaluate between-method agreement. At baseline, 314 YMSM age 18 to 21 years accumulated 674 person-years (PY) of follow-up since first anal intercourse. Considering that 50 men had prevalent HIV infection, the behaviorally imputed HIV incidence was 7.4 per 100 PY. Of the remaining 264 HIV-negative men, 54 seroconverted for HIV infection during the study, accumulating 724 PY of follow-up and a serologically estimated HIV incidence of 7.5 per 100 PY. At baseline, 712 YMSM age 18 to 24 years (including 18 to 21-year-old men analyzed above) accumulated 2143 PY of follow-up since first anal intercourse. Considering that 151 men had prevalent HIV infection, the behaviorally imputed HIV incidence was 7.0 per 100 PY. Of the remaining 561 HIV-negative men, 125 seroconverted for HIV infection during the study, accumulating 1700 PY of follow-up and a serologically estimated HIV incidence of 7.4 per 100 PY. Behavioral imputation and serological estimation are in good agreement when estimating recent HIV incidence in YMSM.

Increasing HIV diagnosis is important for combatting HIV. We invited individuals aged >/= 13 years seeking voluntary HIV testing at Mildmay Clinic in Uganda to undertake a computer or audio-computer-assisted self-interview to facilitate post-test counseling. We evaluated first-visit data from 12,233 consenting individuals between January 2011 and October 2013. HIV prevalence was 39.0%. Of those with HIV, 37.2% already knew they were infected. Undiagnosed infection was associated with not being single, screening positive for depression (aOR 1.16, 95% CI 1.04-1.28), and screening for harmful drinking behavior (aOR 1.23, 95% CI 1.10-1.39). The odds of retesting subsequent to HIV diagnosis were lower for males (aOR 0.80, 95% CI 0.70-0.92) and those screening positive for harmful drinking behavior (aOR 0.77, 95% CI 0.66-0.88). Retesting was also associated with higher education and perceived social status below 'better off'. Our findings reiterate the value of population-based HIV surveys to provide estimates of testing coverage.

BACKGROUND: We investigated progress towards UNAIDS 90-90-90 targets among female sex workers in Kampala, Uganda, who bear a disproportionate burden of HIV. METHODS: Between April and December 2012, 1,487 female sex workers, defined as women, 15-49 years, residing in greater Kampala, and selling sex for money in the last 6 months, were recruited using respondent-driven sampling. Venous blood was collected for HIV and viral load testing [viral load suppression (VLS) defined as <1,000 copies/mL]. We collected data using audio computer-assisted self-interviews and calculated weighted population-level estimates. RESULTS: The median age was 27 years (interquartile range: 23 to 32). HIV seroprevalence was 31.4% (95% confidence interval [CI]: 29.0, 33.7%). Among all female sex workers who tested HIV-positive in the survey (population-level targets), 45.5% (95% CI: 40.1, 51.0) had knowledge of their serostatus (population-level target: 90%), 37.8% (95% CI: 32.2, 42.8) self-reported to be on ART (population-level target: 81%), and 35.2% (95% CI: 20.7, 30.4) were virally suppressed (population-level target: 73%). CONCLUSIONS: HIV prevalence among Kampala female sex workers is high, whereas serostatus knowledge and VLS are far below UNAIDS targets. Kampala female sex workers are in need of intensified and targeted HIV prevention and control efforts.

INTRODUCTION: The UNAIDS 90-90-90 targets to diagnose 90% of people living with HIV, put 90% of them on treatment, and for 90% of them to have suppressed viral load have focused the international HIV response on the goal of eliminating HIV by 2030. They are also a constructive tool for measuring progress toward reaching this goal but their utility is dependent upon data availability. Though more than 25% of new infections are among key populations (KP)- sex workers, men who have sex with men, transgender people, people who inject drugs, and prisoners- and their sex partners, there is a dearth of treatment cascade data for KP. We assess the availability of cascade data and review the opportunities offered by biobehavioral and programme data to inform the HIV response. DISCUSSION: The emphasis on the collection of treatment cascade data among the general population in higher prevalence countries has not led to a similar increase in the availability of cascade data for KP. The limited data available for KP highlight large gaps in service uptake across the cascade, particularly in the first 90, awareness of HIV status. Biobehavioral surveys (BBS), with linked population size estimation, provide population-based data on the treatment cascade and should be conducted every two to three years in locations with services for KP. With the inclusion of viral load testing, these surveys are able to monitor the entire treatment cascade among KP regardless of whether these populations access HIV services targeting the general population or KP. BBS also reach people accessing services and those who do not, thereby providing a unique opportunity to learn about barriers to service uptake including stigma and discrimination. At the same time high-quality programme data can play a complementary role in identifying missed opportunities that can be addressed in real-time. CONCLUSIONS: Data are more important than ever for guiding the HIV response toward reaching 90-90-90 targets and eliminating HIV, particularly in the face of decreased funding for HIV and specifically for KP. Timely high-quality BBS data can be triangulated with high-quality programme data to provide a comprehensive picture of the epidemic response for KP.