Estimating recent HIV incidence among young men who have sex with men: Reinvigorating, validating and implementing Osmond's algorithm for behavioral imputation

A focused multi-state model to estimate the pediatric and adolescent HIV epidemic in Thailand, 2005–2025

Background

We estimated the magnitude of the HIV epidemic among children and youth living with HIV (CYHIV) aged 0–25 years in Thailand, projecting forward from 2005 to 2025, and identified underreported input parameters that influence epidemic projections, in order to inform future public health and research priorities.

Methods

We developed a focused multi-state transition model incorporating perinatally-acquired HIV and non-perinatally-acquired HIV, stratified by population, including men who have sex with men (MSM), female sex workers (FSW), people who inject drugs (PWID), and the remainder of the population (“other”). We populated the model with published and programmatic data from the Thai national AIDS program when available. We projected the period from 2005–2025 and compared model results to programmatic data and projections from other models. In a scenario analysis, we projected the potential impact of pre-exposure prophylaxis (PrEP) for MSM from 2018–2025.

Results

The initial 2005 cohort was comprised of 66,900 CYHIV; 8% CYHIV were <5 years, 21% were 5–14 years, and 71% were 15–25 years of age. By 2020, 94% were projected to be >15 years and infections among MSM constituted 83% of all new HIV infections. The numbers of CYHIV decreased over time, projected to reach 30,760 by 2020 (-54%) and 22,640 by 2025 (-66%). The proportion of all CYHIV aged 0–25 who were diagnosed and on ART increased from 37 to 60% over the 2005–2025 period. Projections were sensitive to variations in assumptions about initial HIV prevalence and incidence among MSM, PWID, and “other” youth.

Conclusions

More data on incidence rates among sexual and gender minority youth and PWID are needed to characterize the role of specific exposures and key populations in the adolescent HIV epidemic. More accurate estimates will project shifts in population and inform more targeted interventions to prevent and care for Thai CYHIV.

Methods and indicators to validate country reductions in incidence of hepatitis C virus infection to elimination levels set by WHO

One of the main goals of the 2016 Global Health Sector Strategy on viral hepatitis is the elimination of hepatitis C virus (HCV) as a public health problem by 2030, defined as an 80% reduction in incidence and 65% reduction in mortality relative to 2015. Although monitoring HCV incidence is key to validating HCV elimination, use of the gold-standard method, which involves prospective HCV retesting of people at risk, can be prohibitively resource-intensive. Additionally, few countries collected quality data in 2015 to enable an 80% decrease by 2030 to be calculated. Here, we first review different methods of monitoring HCV incidence and discuss their resource implications and applicability to various populations. Second, using mathematical models developed for various global settings, we assess whether trends in HCV chronic prevalence or HCV antibody prevalence or scale-up levels for HCV testing, treatment, and preventative interventions can be used as reliable alternative indicators to validate the HCV incidence target. Third, we discuss the advantages and disadvantages of an absolute HCV incidence target and suggest a suitable threshold. Finally, we propose three options that countries can use to validate the HCV incidence target, depending on the available surveillance infrastructure.

HIV prevalence and incidence among men who have sex with men and transgender women in Bangkok, 2014-2018: Outcomes of a consensus development initiative

To reach its goal of ending AIDS by 2030, Thailand has adopted antiretroviral treatment as prevention and HIV pre-exposure prophylaxis for men who have sex with men (MSM) and transgender women (TGW) as its core HIV control strategy. However, in the absence of reliable epidemiologic indicators, the impact of these policies on the course of the HIV epidemic in these groups remains unknown. To help answer this question, we formulated an HIV epidemic consensus initiative for Bangkok, Thailand, to analyze epidemiologic and program data and reach agreement between experts and stakeholders on the evolving state of the HIV epidemic among MSM and TGW. A customized Delphi process was used to consult and consolidate viewpoints of experts and stakeholders. Experts presented and discussed HIV prevalence and incidence data from recent and ongoing studies among MSM and TGW in Bangkok (2014 to 2018) during a meeting with stakeholders representing government, donors, and civil society. Agreement about the course of the HIV epidemic among MSM and TGW was attained by voting consensus. Based on presented data, meeting participants agreed that HIV prevalence and incidence had decreased among Bangkok MSM from 2014 to 2018. Despite these declines, HIV prevalence and incidence were found to remain high. This was particularly the case among younger MSM. Participants agreed that there was no evidence for a decrease in HIV prevalence and incidence among Bangkok TGW. Introduction of antiretroviral treatment as prevention and HIV pre-exposure prophylaxis may have contributed to these declines. However, HIV prevalence and incidence remained high, and no signs of a decrease were reported among Bangkok TGW. At the current rate of new HIV infections in MSM and TGW, Thailand will not reach its goal of ending AIDS by 2030. This HIV consensus initiative may serve as a model for building agreement and advocacy on epidemiologic and program data and their implications for a large metropolitan city.

Regional disparity of HIV incidence and prevalence among men who have sex with men

BACKGROUND

HIV incidence can be estimated with cross-sectional studies using clinical, serological, and molecular data. Worldwide, HIV incidence data in only men who have sex with men (MSM) are scarce and principally focus on those with healthcare or under treatment. However, better estimates can be obtained through studies with national representativeness. The objective was to estimate the prevalence, incidence, and factors associated with acquiring HIV in a national sample of MSM who attend meeting places, considering geographical regions.

METHODS

A nationally representative survey of MSM attending meeting places was performed in Mexico. Participants answered a questionnaire, and a dried blood spot (DBS) was collected. Samples were classified as recent infections using an algorithm with HIV status, antiretroviral therapy, and the result of BED-EIA assay. Parameters were analysed considering regions and demographic and sexual behaviour characteristics.

RESULTS

The national HIV prevalence was 17.4% with regional differences; the highest prevalence (20.7%) was found in Mexico City, and the lowest prevalence was found in the West region (11.5%). The incidence was 9.4 per 100 p/y, with regional values from 6.2 to 13.2 for the Northeast and the Centre regions, respectively. Age, age at sexual debut, low wealth index, and rewarded sex were associated with HIV prevalence. Centre region, use of private clinics as health services, and having sex exclusively with men were associated with recent HIV infections.

CONCLUSIONS

The incidence and prevalence showed regional differences, suggesting a difference in the dynamics of HIV transmission; some regions have a greater case accumulation, and others have a greater rate of new infections. Understanding this dynamic will allow developing health programs focused on HIV prevention or treating people already living with HIV.

HIV prevalence and incidence in a cohort of South African men and transgender women who have sex with men: the Sibanye Methods for Prevention Packages Programme (MP3) project

INTRODUCTION

Men who have sex with men (MSM) and transgender women (TGW) are at increased risk for acquiring HIV, but there are limited HIV incidence data for these key populations in Africa. Understanding HIV prevalence and incidence provides important context for designing HIV prevention strategies, including pre-exposure prophylaxis (PrEP) programmes. We describe HIV prevalence, awareness of HIV infection, HIV incidence and associated factors for a cohort of MSM and TGW in Cape Town and Port Elizabeth, South Africa.

METHODS

From 2015 to 2016, MSM and TGW in Cape Town and Port Elizabeth were enrolled and prospectively followed for 12 months, receiving a comprehensive package of HIV prevention services. HIV testing was conducted at baseline and at follow-up visits (targeted for three, six and twelve months). All HIV-negative PrEP-eligible participants were offered PrEP enrolment during the first four months of study participation. We determined HIV prevalence among participants at baseline, and incidence by repeat screening of initially HIV-negative participants with HIV tests at three, six and twelve months.

RESULTS

Among 292 participants enrolled, HIV prevalence was high (43%; 95% CI: 38 to 49) and awareness of HIV status was low (50%). The 167 HIV-negative participants who were followed prospectively for 144.7 person-years; nine incident HIV infections were documented. Overall annual incidence was 6.2% (CI: 2.8 to 11.8) and did not differ by city. Annual HIV incidence was significantly higher for younger (18 to 19 years) MSM and TGW (MSM: 21.8% (CI: 1.2 to 100); TGW: 31.0 (CI: 3.7, 111.2)). About half of participants started PrEP during the study; the annual incidence of HIV among 82 (49%) PrEP starters was 3.6% (CI: 0.4, 13.1) and among those who did not start PrEP was 7.8% (CI: 3.1, 16.1).

CONCLUSIONS

HIV incidence was high among MSM and TGW in the context of receiving a comprehensive package of prevention interventions and offering of PrEP. PrEP uptake was high; the observed incidence of HIV in those who started PrEP was about half the incidence of HIV in those who did not. Future implementation-oriented studies should focus on decisions to start and continue PrEP for those at highest risk, including young MSM.

Recent declines in HIV infections at Silom Community Clinic Bangkok, Thailand corresponding to HIV prevention scale up: An open cohort assessment 2005-2018

OBJECTIVES

We assessed HIV-1 infection among men who have sex with men (MSM) attending Silom Community Clinic (SCC) in Bangkok, Thailand from 2005 to 2018. Since 2014, Thailand increased implementation of HIV prevention strategies including pre-exposure prophylaxis and Treatment as Prevention.

METHODS

MSM attending SCC were tested for HIV using rapid tests. We assessed trends in HIV prevalence, incidence and compared incidence before and after 2014.

RESULTS

From 2005 to 2018, 14,034 clients attended SCC for HIV testing. The HIV prevalence increased from 19.2% in 2005-2006 to 34-0% in 2010, remained stable until 2016 and decreased to 17.2% in 2018 (p<0.0001). The HIV incidence was 4.1 per 100 person-years (PY), with an inverted U-shape trend and a peak in 2009 (p<0.0001). Incidence among young MSM aged 13-21 years remained high at 10.0 per 100 PY. Among those aged 22-29 years, lower incidence was found from Q 3 2016, with a relative risk reduction of 46.2% (p<0.001); and a similar reduction among those aged ≥30 years from Q4 2014, corresponding to scale up of HIV prevention strategies.

CONCLUSION

We found a decline in HIV infection among Thai MSM. However, incidence remained high among young MSM.

Estimation of HIV incidence and its trend in three key populations in Iran

In Iran, People Who Inject Drugs (PWID), Female Sex Workers (FSW), and prisoners are the main key populations at risk of HIV infection. This study aimed to evaluate the trend of HIV incidence among PWID, FSW and prisoners as an impact measure of HIV harm reduction and prevention efforts in Iran. Data were obtained from the two rounds of national bio-behavioral surveillance surveys among FSW (2010 (n = 872), 2015 (n = 1339)), PWID (2010 (n = 2417), 2014 (n = 2307)), and prisoners (2009 (n = 4536), 2013 (n = 5390)) through facility-based (FSW and PWID surveys) and cluster sampling (prisoner surveys). Time-at-risk was calculated assuming the age at first sex or drug injection as the beginning of the at-risk period and the age at the time of the interview or date when they received a positive HIV test result as the end of this period, adjusted for interval censoring. HIV incidence among PWID in 2014 was 5.39 (95% CI 4.71, 6.16) per 1,000 person-years (PY), significantly lower than in 2009 (17.07, 95% CI 15.34, 19.34). Similarly, HIV incidence was 1.12 (95% CI 0.77, 1.64) per 1,000 PY among FSW in 2015, a significant drop from 2010 (2.38, 95% CI 1.66, 3.40). Also, HIV incidence decreased among prisoners from 1.34 (95% CI: 1.08, 1.67) in 2009 to 0.49 (95% CI: 0.39, 0.61) per 1,000 PY in 2013. Our findings suggest that after an increase in the 2000s, the HIV incidence may have been decreased and stabilized among key populations in Iran.