Mapping the number of female sex workers in countries across sub-Saharan Africa.

Female sex workers (FSW) are affected by individual, network, and structural risks, making them vulnerable to poor health and well-being. HIV prevention strategies and local community-based programs can rely on estimates of the number of FSW to plan and implement differentiated HIV prevention and treatment services. However, there are limited systematic assessments of the number of FSW in countries across sub-Saharan Africa to facilitate the identification of prevention and treatment gaps. Here we provide estimated population sizes of FSW and the corresponding uncertainties for almost all sub-national areas in sub-Saharan Africa. We first performed a literature review of FSW size estimates and then developed a Bayesian hierarchical model to synthesize these size estimates, resolving competing size estimates in the same area and producing estimates in areas without any data. We estimated that there are 2.5 million (95% uncertainty interval 1.9 to 3.1) FSW aged 15 to 49 in sub-Saharan Africa. This represents a proportion as percent of all women of childbearing age of 1.1% (95% uncertainty interval 0.8 to 1.3%). The analyses further revealed substantial differences between the proportions of FSW among adult females at the sub-national level and studied the relationship between these heterogeneities and many predictors. Ultimately, achieving the vision of no new HIV infections by 2030 necessitates dramatic improvements in our delivery of evidence-based services for sex workers across sub-Saharan Africa.

Graded FGF activity patterns distinct cell types within the apical sensory organ of the sea anemone Nematostella vectensis.

Bilaterian animals have evolved complex sensory organs comprised of distinct cell types that function coordinately to sense the environment. Each sensory unit has a defined architecture built from component cell types, including sensory cells, non-sensory support cells, and dedicated sensory neurons. Whether this characteristic cellular composition is present in the sensory organs of non-bilaterian animals is unknown. Here, we interrogate the cell type composition and gene regulatory networks controlling development of the larval apical sensory organ in the sea anemone Nematostella vectensis. Using single cell RNA sequencing and imaging approaches, we reveal two unique cell types in the Nematostella apical sensory organ, GABAergic sensory cells and a putative non-sensory support cell population. Further, we identify the paired-like (PRD) homeodomain gene prd146 as a specific sensory cell marker and show that Prd146+ sensory cells become post-mitotic after gastrulation. Genetic loss of function approaches show that Prd146 is essential for apical sensory organ development. Using a candidate gene knockdown approach, we place prd146 downstream of FGF signaling in the apical sensory organ gene regulatory network. Further, we demonstrate that an aboral FGF activity gradient coordinately regulates the specification of both sensory and support cells. Collectively, these experiments define the genetic basis for apical sensory organ development in a non-bilaterian animal and reveal an unanticipated degree of complexity in a prototypic sensory structure.

Regulation of stem cell identity by miR-200a during spinal cord regeneration.

Axolotls are an important model organism for multiple types of regeneration, including functional spinal cord regeneration. Remarkably, axolotls can repair their spinal cord after a small lesion injury and can also regenerate their entire tail following amputation. Several classical signaling pathways that are used during development are reactivated during regeneration, but how this is regulated remains a mystery. We have previously identified miR-200a as a key factor that promotes successful spinal cord regeneration. Here, using RNA-seq analysis, we discovered that the inhibition of miR-200a results in an upregulation of the classical mesodermal marker brachyury in spinal cord cells after injury. However, these cells still express the neural stem cell marker sox2. In vivo cell tracking allowed us to determine that these cells can give rise to cells of both the neural and mesoderm lineage. Additionally, we found that miR-200a can directly regulate brachyury via a seed sequence in the 3'UTR of the gene. Our data indicate that miR-200a represses mesodermal cell fate after a small lesion injury in the spinal cord when only glial cells and neurons need to be replaced.

Global assessment of existing HIV and key population stigma indicators: A data mapping exercise to inform country-level stigma measurement.

BACKGROUND: Stigma is an established barrier to the provision and uptake of HIV prevention, diagnostic, and treatment services. Despite consensus on the importance of addressing stigma, there are currently no country-level summary measures to characterize stigma and track progress in reducing stigma around the globe. This data mapping exercise aimed to assess the potential for existing data to be used to summarize and track stigma, including discrimination, related to HIV status, or key population membership at the country level. METHODS AND FINDINGS: This study assessed existing indicators of stigma related to living with HIV or belonging to 1 of 4 key populations including gay men and other men who have sex with men, sex workers, people who use drugs, and transgender persons. UNAIDS Strategic Information Department led an initial drafting of possible domains, subdomains, and indicators, and a 3-week e-consultation was held to provide feedback. From the e-consultation, 44 indicators were proposed for HIV stigma; 14 for sexual minority stigma (including sexual behavior or orientation) related to men who have sex with men; 12 for sex work stigma; 10 for drug use stigma; and 17 for gender identity stigma related to transgender persons. We conducted a global data mapping exercise to identify and describe the availability and quality of stigma data across countries with the following sources: UNAIDS National Commitments and Policies Instrument (NCPI) database; Multiple Indicator Cluster Surveys (MICS); Demographic and Health Surveys (DHS); People Living with HIV Stigma Index surveys; HIV Key Populations Data Repository; Integrated Biological and Behavioral Surveys (IBBS); and network databases. Data extraction was conducted between August and November 2020. Indicators were evaluated based on the following: if an existing data source could be identified; the number of countries for which data were available for the indicator at present and in the future; variation in the indicator across countries; and considerations of data quality or accuracy. This mapping exercise resulted in the identification of 24 HIV stigma indicators and 10 key population indicators as having potential to be used at present in the creation of valid summary measures of stigma at the country level. These indicators may allow assessment of legal, societal, and behavioral manifestations of stigma across population groups and settings. Study limitations include potential selection bias due to available data sources to the research team and other biases due to the exploratory nature of this data mapping process. CONCLUSIONS: Based on the current state of data available, several indicators have the potential to characterize the level and nature of stigma affecting people living with HIV and key populations across countries and across time. This exercise revealed challenges for an empirical process reliant on existing data to determine how to weight and best combine indicators into indices. However, results for this study can be combined with participatory processes to inform summary measure development and set data collection priorities going forward.

Wound healing across the animal kingdom: Crosstalk between the immune system and the extracellular matrix.

Tissue regeneration is widespread in the animal kingdom. To date, key roles for different molecular and cellular programs in regeneration have been described, but the ultimate blueprint for this talent remains elusive. In animals capable of tissue regeneration, one of the most crucial stages is wound healing, whose main goal is to close the wound and prevent infection. In this stage, it is necessary to avoid scar formation to facilitate the activation of the immune system and remodeling of the extracellular matrix, key factors in promoting tissue regeneration. In this review, we will discuss the current state of knowledge regarding the role of the immune system and the interplay with the extracellular matrix to trigger a regenerative response.

Prevalence and burden of HBV co-infection among people living with HIV: A global systematic review and meta-analysis.

Globally, in 2017 35 million people were living with HIV (PLHIV) and 257 million had chronic HBV infection (HBsAg positive). The extent of HIV-HBsAg co-infection is unknown. We undertook a systematic review to estimate the global burden of HBsAg co-infection in PLHIV. We searched MEDLINE, Embase and other databases for published studies (2002-2018) measuring prevalence of HBsAg among PLHIV. The review was registered with PROSPERO (#CRD42019123388). Populations were categorized by HIV-exposure category. The global burden of co-infection was estimated by applying regional co-infection prevalence estimates to UNAIDS estimates of PLHIV. We conducted a meta-analysis to estimate the odds of HBsAg among PLHIV compared to HIV-negative individuals. We identified 506 estimates (475 studies) of HIV-HBsAg co-infection prevalence from 80/195 (41.0%) countries. Globally, the prevalence of HIV-HBsAg co-infection is 7.6% (IQR 5.6%-12.1%) in PLHIV, or 2.7 million HIV-HBsAg co-infections (IQR 2.0-4.2). The greatest burden (69% of cases; 1.9 million) is in sub-Saharan Africa. Globally, there was little difference in prevalence of HIV-HBsAg co-infection by population group (approximately 6%-7%), but it was slightly higher among people who inject drugs (11.8% IQR 6.0%-16.9%). Odds of HBsAg infection were 1.4 times higher among PLHIV compared to HIV-negative individuals. There is therefore, a high global burden of HIV-HBsAg co-infection, especially in sub-Saharan Africa. Key prevention strategies include infant HBV vaccination, including a timely birth-dose. Findings also highlight the importance of targeting PLHIV, especially high-risk groups for testing, catch-up HBV vaccination and other preventative interventions. The global scale-up of antiretroviral therapy (ART) for PLHIV using a tenofovir-based ART regimen provides an opportunity to simultaneously treat those with HBV co-infection, and in pregnant women to also reduce mother-to-child transmission of HBV alongside HIV.

Global Trends of Monitoring and Data Collection on the HIV Response among Key Populations Since the 2001 UN Declaration of Commitment on HIV/AIDS.

Monitoring and evaluation indicators for HIV programs' response to the epidemic among key populations (sex workers, people who inject drugs, men who have sex with men, transgender people) are critical for reviewing the global response. From the beginning of global reporting, insufficiency of data has been a challenge for monitoring the epidemic response among key populations. However, key populations were only indirectly referenced in the 2001 Declaration of Commitment. By the 2006 Political Declaration on HIV/AIDS, data from key populations were still not required from every country, and were sparsely reported compared to other indicators. The 2011 Political Declaration on HIV/AIDS referenced key populations by name for the first time. In 2006, fewer than twenty countries (10%) reported HIV prevalence among key populations, whereas in 2012 the number of countries surpassed sixty (30%).

Dynamic membrane depolarization is an early regulator of ependymoglial cell response to spinal cord injury in axolotl.

Salamanders, such as the Mexican axolotl, are some of the few vertebrates fortunate in their ability to regenerate diverse structures after injury. Unlike mammals they are able to regenerate a fully functional spinal cord after injury. However, the molecular circuitry required to initiate a pro-regenerative response after spinal cord injury is not well understood. To address this question we developed a spinal cord injury model in axolotls and used in vivo imaging of labeled ependymoglial cells to characterize the response of these cells to injury. Using in vivo imaging of ion sensitive dyes we identified that spinal cord injury induces a rapid and dynamic change in the resting membrane potential of ependymoglial cells. Prolonged depolarization of ependymoglial cells after injury inhibits ependymoglial cell proliferation and subsequent axon regeneration. Using transcriptional profiling we identified c-Fos as a key voltage sensitive early response gene that is expressed specifically in the ependymoglial cells after injury. This data establishes that dynamic changes in the membrane potential after injury are essential for regulating the specific spatiotemporal expression of c-Fos that is critical for promoting faithful spinal cord regeneration in axolotl.

Male sex workers: practices, contexts, and vulnerabilities for HIV acquisition and transmission.

Male sex workers who sell or exchange sex for money or goods encompass a very diverse population across and within countries worldwide. Information characterising their practices, contexts where they live, and their needs is limited, because these individuals are generally included as a subset of larger studies focused on gay men and other men who have sex with men (MSM) or even female sex workers. Male sex workers, irrespective of their sexual orientation, mostly offer sex to men and rarely identify as sex workers, using local or international terms instead. Growing evidence indicates a sustained or increasing burden of HIV among some male sex workers within the context of the slowing global HIV pandemic. Several synergistic facilitators could be potentiating HIV acquisition and transmission among male sex workers, including biological, behavioural, and structural determinants. Criminalisation and intersectional stigmas of same-sex practices, commercial sex, and HIV all augment risk for HIV and sexually transmitted infections among male sex workers and reduce the likelihood of these people accessing essential services. These contexts, taken together with complex sexual networks among male sex workers, define this group as a key population underserved by current HIV prevention, treatment, and care services. Dedicated efforts are needed to make those services available for the sake of both public health and human rights. Evidence-based and human rights-affirming services dedicated specifically to male sex workers are needed to improve health outcomes for these men and the people within their sexual networks.

The importance of assessing self-reported HIV status in bio-behavioural surveys.

In bio-behavioural surveys measuring prevalence of infection with human immunodeficiency virus (HIV), respondents should be asked the results of their last HIV test. However, many government authorities, nongovernmental organizations, researchers and other civil society stakeholders have stated that respondents involved in such surveys should not be asked to self-report their HIV status. The reasons offered for not asking respondents to report their status are that responses may be inaccurate and that asking about HIV status may violate the respondents' human rights and exacerbate stigma and discrimination. Nevertheless, we contend that, in the antiretroviral therapy era, asking respondents in bio-behavioural surveys to self-report their HIV status is essential for measuring and improving access to - and coverage of - services for the care, treatment and prevention of HIV infection. It is also important for estimating the true size of the unmet needs in addressing the HIV epidemic and for interpreting the behaviours associated with the acquisition and transmission of HIV infection correctly. The data available indicate that most participants in health-related surveys are willing to respond to a question about HIV status - as one of possibly several sensitive questions about sexual and drug use behaviours. Ultimately, normalizing the self-reporting of HIV status could help the global community move from an era of so-called exceptionalism to one of destigmatization - and so improve the epidemic response worldwide.

Dans les enquêtes bio-comportementales évaluant la prévalence de l'infection par le virus de l'immunodéficience humaine (VIH), il conviendrait de demander aux répondants le résultat de leur dernier test de dépistage du VIH. Mais nombre d'autorités gouvernementales, d'organisations non gouvernementales, de chercheurs et d'acteurs de la société civile sont défavorables à ce que l'on demande aux répondants de déclarer leur statut VIH dans ce type d'enquêtes. Parmi les raisons invoquées pour ne pas demander le statut VIH figure le fait que les réponses peuvent être inexactes et qu'une telle demande pourrait transgresser les droits humains des répondants et accentuer les problèmes de stigmatisation et de discrimination. Néanmoins, nous soutenons qu'aujourd'hui, à l'ère de la thérapie antirétrovirale, le fait de demander leur statut VIH aux répondants des enquêtes bio-comportementales est essentiel à des fins d'évaluation des services de soins, traitement et prévention de l'infection à VIH et pour en optimiser l'accès et la couverture. Cela est également fondamental pour évaluer la véritable ampleur des besoins non satisfaits dans la gestion de l'épidémie de VIH et pour correctement interpréter les comportements associés à l'acquisition et à la transmission du VIH. Les données disponibles indiquent que la plupart des participants aux enquêtes liées à la santé acceptent de répondre à une question sur leur statut VIH, parmi d'autres questions sensibles concernant les comportements sexuels et l'usage de drogues. Enfin, une normalisation de l'auto-déclaration du statut VIH pourrait aider la communauté mondiale à dépasser ce que l'on appelle « l'exceptionnalisme ¼ pour ouvrir une ère de déstigmatisation, ce qui permettrait d'améliorer la réponse face à l'épidémie dans le monde entier.

Durante la realización de encuestas bioconductuales que miden la prevalencia del contagio del virus de la inmunodeficiencia humana (VIH), los encuestados deberían entregar los resultados de la última prueba de VIH a la que se hayan sometido. No obstante, muchas autoridades gubernamentales, organizaciones no gubernamentales, investigadores y otras partes interesadas de la sociedad civil han declarado que las personas encuestadas implicadas en dichas encuestas no deberían tener que realizar una autodeclaración de su estado con relación al VIH. Las razones expuestas para no pedir a los encuestados que informen de su condición son que las respuestas pueden ser inexactas y que preguntarles por su estado en relación al VIH puede violar sus derechos humanos y exacerbar la estigmatización y la discriminación. Sin embargo, se sostiene que, en la era de terapias antirretrovirales, solicitar a los encuestados en encuestas bioconductuales que declaren su estado en relación al VIH es fundamental para medir y mejorar el acceso a, y la cobertura de, servicios para la atención, el tratamiento y la prevención del contagio del VIH. También es importante para estimar el verdadero alcance de las necesidades insatisfechas a la hora de abordar la epidemia de VIH, así como para interpretar las conductas asociadas a la adquisición y transmisión del virus de forma adecuada. Los datos disponibles indican que la mayor parte de los participantes en encuestas relacionadas con la salud están dispuestos a responder una pregunta sobre su estado en relación al VIH como una de las muchas posibles preguntas delicadas sobre comportamientos sexuales y de consumo de drogas. Por último, normalizar las declaraciones sobre el estado en relación al VIH podría ayudar a la comunidad mundial a pasar de una época caracterizada por el "excepcionalismo" a una caracterizada por la "desestigmatización", y, de este modo, mejorar la respuesta frente a las epidemias a nivel mundial.

Routine feedback of test results to participants in clinic- and survey-based surveillance of HIV.

Surveillance for human immunodeficiency virus (HIV) in low- and middle-income countries started in the 1980s. However, the questions of whether the results of HIV tests should be given to participants, and if so how, has still not been resolved. In the absence of effective treatment, it was considered acceptable to withhold results from HIV-positive participants. However, when antiretroviral treatment is available, some argue for beneficence - that it is the researcher's duty to return the test results to all those who provide samples for surveillance. The corollary is that only participants who wish to receive their test results would be eligible to participate in surveys. Others argue for autonomy - that to obtain a more representative result for the general population, surveys should not exclude participants who do not wish to receive their test results. This round table discussion takes a closer look at those two arguments. We believe that the global community should work towards routine feedback of HIV surveillance while ensuring that participants receive and understand their test results.

La surveillance du virus de l'immunodéficience humaine (VIH) dans les pays à revenu faible et intermédiaire a commencé dans les années 1980. Les résultats des tests VIH doivent-ils être communiqués aux participants et si oui, comment ? En l'absence de traitement efficace, il avait été jugé acceptable de ne pas divulguer leur séropositivité aux participants infectés par le VIH. En revanche, dès lors qu'un traitement antirétroviral est disponible, certains évoquent le principe de bienfaisance et estiment qu'il est du devoir du chercheur de communiquer les résultats des tests à tous ceux qui ont fourni des échantillons à des fins de surveillance. Mais le corollaire est que seuls les participants qui acceptent d'être informés des résultats de leur test seraient alors éligibles pour participer à ce type d'enquêtes. D'autres avancent le principe d'autonomie, en disant que pour obtenir un résultat plus représentatif de la population générale, ces enquêtes ne doivent pas exclure les participants qui ne souhaitent pas recevoir leurs résultats. Cette table ronde examine en détail ces deux positions. Nous pensons que la communauté internationale devrait œuvrer pour une rétroaction systématique autour de la surveillance du VIH, en veillant à ce que les participants reçoivent et comprennent les résultats de leurs tests.

El seguimiento del virus de la inmunodeficiencia humana (VIH) en países de ingresos bajos y medios empezó en los años ochenta. ¿Deberían proporcionarse los resultados de las pruebas del VIH a los participantes? Si es así, ¿de qué modo? A falta de tratamiento efectivo, se consideró aceptable retener los resultados de los participantes VIH-positivos. Sin embargo, cuando se dispone de tratamiento antirretroviral, hay quien defiende la beneficencia, es decir, que es el deber del investigador informar de los resultados de las pruebas a todos aquellos que proporcionen muestras para el seguimiento. La consecuencia de esto es que solo los participantes que quieran recibir los resultados de sus pruebas reunirían los requisitos para participar en las encuestas. Otros defienden la autonomía, es decir, que para obtener un resultado más representativo de la población en general, las encuestas no deberían excluir a los participantes que no quieran recibir los resultados de sus pruebas. Este debate de mesa redonda analiza con más detenimiento estos dos argumentos. Creemos que la comunidad mundial debería trabajar por la información rutinaria del seguimiento del VIH, al mismo tiempo que garantiza que los participantes reciban y entiendan los resultados de sus pruebas.

Strategic information is everyone's business: perspectives from an international stakeholder meeting to enhance strategic information data along the HIV Cascade for people who inject drugs.

People who inject drugs (PWID) are at increased HIV transmission risk because of unsafe injecting practices and a host of other individual, network, and structural factors. Thus, PWID have a great need for services within the Cascade of HIV prevention, diagnosis, care, and treatment (HIV Cascade). Yet the systems that monitor their progress through the Cascade are often lacking. Subsequently, fewer reliable data are available to guide programs targeting this key population (KP). Programmatic data, which are helpful in tracking PWID through the Cascade, also are limited because not all countries have harm reduction programming from which to estimate Cascade indicators. Also, due to stigma and the illegal nature of drug use, PWID may not disclose their drug use behavior or HIV status when accessing services. Consequently, PWID appear to have low HIV testing rates and, for those living with HIV, lower access to health services and lower viral suppression rates than do other KP groups. This commentary, based on outcomes from an international stakeholder meeting, identifies data gaps and proposes solutions to strengthen strategic information (SI), the systematic collection, analysis, and dissemination of information, to optimize HIV prevention, care, and treatment programming for PWID.

Repeated surveys of people who inject drugs: The exception, not the rule.

HIV surveillance is the continuous, systematic collection, analysis and interpretation of HIV-related data needed for the planning, implementation, and evaluation of the HIV response. Some communities are affected by HIV more than others and require more focused responses; one of these communities are people who inject drugs (PWID.) We reviewed HIV surveillance among PWID across all countries. We identified countries with specific repeated surveys among PWID using data submitted to the UNAIDS Global AIDS Monitoring system, supplemented by national reports from countries that do not report to UNAIDS. Countries with four or more surveys since 2011, with at least one since 2017, were sent a brief survey to ask the use and relevance of the collected data for their respective HIV responses and the challenges they foresaw. Thirty-two countries were polled, of which 17 responded. Respondents highlighted the utility of the surveys to measure HIV prevalence, antiretroviral treatment and other service use. Future funding and maintaining capacity to implement surveys are current or coming challenges.

Piloting a simplified bio-behavioural survey methodology, the BBS-Lite, among people who inject drugs in Georgia.

BACKGROUND: During 2021 and 2023 two simplified Biological and Behavioural Study (BBS-Lite) surveys, and in 2022 one Standard Integrated Biological and Behavioural Study (IBBS), were conducted among people who inject drugs in seven cities in Georgia. From these, an opportunity to compare the implementation of these survey methods and results was able to be gained. METHODS: The two survey types were compared to find points of similarity and difference in their methodologies. The methodologies of the IBBS and BBS-Lite studies shared many characteristics, including the cities where they were implemented, recruitment criteria, sample sizes, and common questionnaire items. All studies were multi-centre cross-sectional involving administration of a face-to-face behavioural questionnaire and collection of biological specimens for testing of HIV, syphilis, hepatitis B virus (HBV), and hepatitis C virus (HCV). The main differences were in the sampling methods. The IBBS utilised respondent-driven sampling (RDS) while participants of the BBS-Lite studies were enrolled through consecutive recruitment at the harm reduction (HR) programme sites and on outreach and through snowball sampling. We compared the results from each study as well as the implementation modalities such as time taken and budgetary requirements, and the complexity of implementation. RESULTS: Considerably less time was required for recruitment, as well as for interviewing, data entry (4 times less) and the analysis for the BSS-Lite studies compared to the IBBS. The BSS-Lite study budgets were at least 2.5 times less than of the IBBS study. The recruited samples were comparable for age distribution, median age at first injection, the last drug injected, sharing of drug injecting equipment or receiving opioid agonist maintenance treatment (OAMT) during the last 12 months. HIV and HCV prevalence were similar including for stratifications by age, client status and city of recruitment. CONCLUSION: Our findings have demonstrated that if implemented on a regular basis, the BBS-Lite can be a complementary solution for systematic data collection, filling surveillance gaps and addressing the challenges that persist in obtaining important data on people who inject drugs (PWID) between IBBS rounds in the country. The methodology is recommended for testing in other settings and in other key populations. In addition, the data collected on a routine base can help the harm reduction (HR) program to better understand the changes in the drug scene and observe new trends in HIV risks and drug injecting behaviours, possible barriers for access to harm reduction, drug treatment, and HIV and/or viral hepatitis testing and treatment services.

New HIV Infections Among Key Populations and Their Partners in 2010 and 2022, by World Region: A Multisources Estimation.

BACKGROUND: Previously, The Joint United Nations Programme on HIV/AIDS estimated proportions of adult new HIV infections among key populations (KPs) in the last calendar year, globally and in 8 regions. We refined and updated these, for 2010 and 2022, using country-level trend models informed by national data. METHODS: Infections among 15-49 year olds were estimated for sex workers (SWs), male clients of female SW, men who have sex with men (MSM), people who inject drugs (PWID), transgender women (TGW), and non-KP sex partners of these groups. Transmission models used were Goals (71 countries), AIDS Epidemic Model (13 Asian countries), Optima (9 European and Central Asian countries), and Thembisa (South Africa). Statistical Estimation and Projection Package fits were used for 15 countries. For 40 countries, new infections in 1 or more KPs were approximated from first-time diagnoses by the mode of transmission. Infection proportions among nonclient partners came from Goals, Optima, AIDS Epidemic Model, and Thembisa. For remaining countries and groups not represented in models, median proportions by KP were extrapolated from countries modeled within the same region. RESULTS: Across 172 countries, estimated proportions of new adult infections in 2010 and 2022 were both 7.7% for SW, 11% and 20% for MSM, 0.72% and 1.1% for TGW, 6.8% and 8.0% for PWID, 12% and 10% for clients, and 5.3% and 8.2% for nonclient partners. In sub-Saharan Africa, proportions of new HIV infections decreased among SW, clients, and non-KP partners but increased for PWID; elsewhere these groups' 2010-to-2022 differences were opposite. For MSM and TGW, the proportions increased across all regions. CONCLUSIONS: KPs continue to have disproportionately high HIV incidence.

Comparison of Empirically Derived and Model-Based Estimates of Key Population HIV Incidence and the Distribution of New Infections by Population Group in Sub-Saharan Africa.

BACKGROUND: The distribution of new HIV infections among key populations, including female sex workers (FSWs), gay men and other men who have sex with men (MSM), and people who inject drugs (PWID) are essential information to guide an HIV response, but data are limited in sub-Saharan Africa (SSA). We analyzed empirically derived and mathematical model-based estimates of HIV incidence among key populations and compared with the Joint United Nations Programme on HIV/AIDS (UNAIDS) estimates. METHODS: We estimated HIV incidence among FSW and MSM in SSA by combining meta-analyses of empirical key population HIV incidence relative to the total population incidence with key population size estimates (KPSE) and HIV prevalence. Dynamic HIV transmission model estimates of HIV incidence and percentage of new infections among key populations were extracted from 94 country applications of 9 mathematical models. We compared these with UNAIDS-reported distribution of new infections, implied key population HIV incidence and incidence-to-prevalence ratios. RESULTS: Across SSA, empirical FSW HIV incidence was 8.6-fold (95% confidence interval: 5.7 to 12.9) higher than total population female 15-39 year incidence, and MSM HIV incidence was 41.8-fold (95% confidence interval: 21.9 to 79.6) male 15-29 year incidence. Combined with KPSE, these implied 12% of new HIV infections in 2021 were among FSW and MSM (5% and 7% respectively). In sensitivity analysis varying KPSE proportions within 95% uncertainty range, the proportion of new infections among FSW and MSM was between 9% and 19%. Insufficient data were available to estimate PWID incidence rate ratios. Across 94 models, median proportion of new infections among FSW, MSM, and PWID was 6.4% (interquartile range 3.2%-11.7%), both much lower than the 25% reported by UNAIDS. CONCLUSION: Empirically derived and model-based estimates of HIV incidence confirm dramatically higher HIV risk among key populations in SSA. Estimated proportions of new infections among key populations in 2021 were sensitive to population size assumptions and were substantially lower than estimates reported by UNAIDS.

Effectiveness of respondent driven sampling to recruit undocumented Central American immigrant women in Houston, Texas for an HIV behavioral survey.

Respondent driven sampling (RDS) is widely used for HIV behavioral research among sex workers, drug users, and other hidden populations, but has had limited application in immigrant populations in the U.S. In 2010, we used RDS to recruit undocumented Central American immigrant women in Houston, Texas for an HIV behavioral survey. Beginning with three initial participants we recruited 226 women within 16 weeks. Social networks were dense and participants adopted the recruitment system with reasonable ease. Homophily scores indicated moderate within-group preference by country of origin. However, cross-group recruitment was sufficient to achieve a diverse sample that attained equilibrium for all demographic and sexual behavior characteristics. Overall, RDS was easy to implement, attained a large sample in a relatively short period of time, and reached an otherwise hidden population. Our results suggest that RDS is an effective method for recruiting undocumented Latina immigrants for HIV behavioral surveys.

HIV prevalence in transgender populations and cisgender men who have sex with men in sub-Saharan Africa 2010-2022: a meta-analysis.

Introduction: The Global AIDS Strategy 2021-2026 calls for equitable and equal access to HIV prevention and treatment programmes for all populations to reduce HIV incidence and end HIV/AIDS as a public health threat by 2030. Transgender populations (TGP), including transmen (TGM) and transwomen (TGW) are populations that have been marginalised and are at high risk of HIV infection in sub-Saharan Africa (SSA). Limited surveillance data on HIV among TGP are available in the region to guide programmatic responses and policymaking. Surveillance data on cisgender men who have sex with men (cis-MSM) are comparatively abundant and may be used to infer TGP HIV prevalence. Methods: Data from key population surveys conducted in SSA between 2010-2022 were identified from existing databases and survey reports. Studies that collected HIV prevalence on both TGP and cis-MSM populations were analysed in a random effect meta-analysis to estimate the ratio of cis-MSM:TGW HIV prevalence. Results: Eighteen studies were identified encompassing 8,052 TGW and 19,492 cis-MSM. TGW HIV prevalence ranged from 0-71.6% and cis-MSM HIV prevalence from 0.14-55.7%. HIV prevalence in TGW was 50% higher than in cis-MSM (prevalence ratio (PR) 1.50 95% CI 1.26-1.79). TGW HIV prevalence was highly correlated with year/province-matched cis-MSM HIV prevalence (R2 = 0.62), but poorly correlated with year/province-matched total population HIV prevalence (R2 = 0.1). Five TGM HIV prevalence estimates were identified ranging from 1-24%. Insufficient TGM data were available to estimate cis-MSM:TGM HIV prevalence ratios. Conclusion: Transgender women experience a significantly greater HIV burden than cis-MSM in SSA. Bio-behavioural surveys designed and powered to measure determinants of HIV infection, treatment coverage, and risk behaviours among transgender populations, distinct from cis-MSM, will improve understanding of HIV risk and vulnerabilities among TGP and support improved programmes.

Prevalence of HIV risk behaviors among undocumented Central American immigrant women in Houston, Texas.

Undocumented Central American immigrants in the United States are disproportionately affected by HIV infection. However, epidemiological data on sexual behaviors among undocumented women are sparse and the extent to which behaviors vary by duration of residence in the U.S.is largely unknown. In 2010, we used respondent driven sampling to conduct an HIV behavioral survey among Central American immigrant women residing in Houston, Texas without a valid U.S. visa or residency papers. Here we describe the prevalence of sexual risk behaviors and compare recent (5 years or less in the U.S.) and established immigrants (over 5 years in the U.S.) to elucidate changes in sexual risk behaviors over time. Our data suggest that recent immigrants have less stable sexual partnerships than established immigrants, as they are more likely to have multiple and concurrent sexual partnerships, as well as partnerships of shorter duration.

The architecture and operating mechanism of a cnidarian stinging organelle.

The stinging organelles of jellyfish, sea anemones, and other cnidarians, known as nematocysts, are remarkable cellular weapons used for both predation and defense. Nematocysts consist of a pressurized capsule containing a coiled harpoon-like thread. These structures are in turn built within specialized cells known as nematocytes. When triggered, the capsule explosively discharges, ejecting the coiled thread which punctures the target and rapidly elongates by turning inside out in a process called eversion. Due to the structural complexity of the thread and the extreme speed of discharge, the precise mechanics of nematocyst firing have remained elusive7. Here, using a combination of live and super-resolution imaging, 3D electron microscopy, and genetic perturbations, we define the step-by-step sequence of nematocyst operation in the model sea anemone Nematostella vectensis. This analysis reveals the complex biomechanical transformations underpinning the operating mechanism of nematocysts, one of nature's most exquisite biological micro-machines. Further, this study will provide insight into the form and function of related cnidarian organelles and serve as a template for the design of bioinspired microdevices.