HIV incidence and impact of interventions among female sex workers and their clients in the Middle East and north Africa: a modelling study

Understanding dynamics and overlapping epidemiologies of HIV, HSV-2, chlamydia, gonorrhea, and syphilis in sexual networks of men who have sex with men

Introduction

We aimed to investigate the overlapping epidemiologies of human immunodeficiency virus (HIV), herpes simplex virus type 2 (HSV-2), chlamydia, gonorrhea, and syphilis in sexual networks of men who have sex with men (MSM), and to explore to what extent the epidemiology of one sexually transmitted infection (STI) relates to or differs from that of another STI.

Methods

An individual-based Monte Carlo simulation model was employed to simulate the concurrent transmission of STIs within diverse sexual networks of MSM. The model simulated sexual partnering, birth, death, and STI transmission within each specific sexual network. The model parameters were chosen based on the current knowledge and understanding of the natural history, transmission, and epidemiology of each considered STI. Associations were measured using the Spearman's rank correlation coefficient (SRCC) and maximal information coefficient (MIC).

Results

A total of 500 sexual networks were simulated by varying the mean and variance of the number of partners for both short-term and all partnerships, degree correlation, and clustering coefficient. HSV-2 had the highest current infection prevalence across the simulations, followed by HIV, chlamydia, syphilis, and gonorrhea. Threshold and saturation effects emerged in the relationship between STIs across the simulated networks, and all STIs demonstrated moderate to strong associations. The strongest current infection prevalence association was between HIV and gonorrhea, with an SRCC of 0.84 (95% CI: 0.80-0.87) and an MIC of 0.81 (95% CI: 0.74-0.88). The weakest association was between HSV-2 and syphilis, with an SRCC of 0.54 (95% CI: 0.48-0.59) and an MIC of 0.57 (95% CI, 0.49-0.65). Gonorrhea exhibited the strongest associations with the other STIs while syphilis had the weakest associations. Across the simulated networks, proportions of the population with zero, one, two, three, four, and five concurrent STI infections were 48.6, 37.7, 11.1, 2.4, 0.3, and < 0.1%, respectively. For lifetime exposure to these infections, these proportions were 13.6, 21.0, 22.9, 24.3, 13.4, and 4.8%, respectively.

Conclusion

STI epidemiologies demonstrate substantial overlap and associations, alongside nuanced differences that shape a unique pattern for each STI. Gonorrhea exhibits an "intermediate STI epidemiology," reflected by the highest average correlation coefficient with other STIs.

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.

Trends and projection of incidence, mortality, and disability-adjusted life years of HIV in the Middle East and North Africa (1990-2030)

Evidence shows a growing trend of the HIV epidemic in the Middle East and North Africa (MENA). We aimed to project the incidence, mortality, and disability-adjusted life years (DALY) in the region from 1990 to 2019 and assess its trend by 2025, and 2030. We extracted the HIV incidence, mortality, and DALY data from the Global Burden of Disease (GBD) and UNAIDS databases. The joinpoint regression model was used to examine changes in HIV trends. The trend changes were estimated by average annual percent change (AAPC). In most countries, an increasing trend was observed in HIV incidence, mortality, and DALY. Specifically, the highest growth in the annual incidence rate was related to Egypt (AAPC = 14.4, GBD) and Iran (AAPC = 9.6, UNAIDS). Notably, Qatar (AAPC = - 5.6, GBD), Bahrain (AAPC = - 3.3, GBD), and Somalia (AAPC = - 4.2, UNAIDS) demonstrated a significant reduction in incidence. Regarding mortality rates, Djibouti (AAPC = 24.2, GBD) and Iran (AAPC = 16.2, UNAIDS) exhibited a significant increasing pattern. Furthermore, the estimated increase in incidence by 2030 was most marked in Djibouti (985%) and Iran (174%). Iran (422%) and Egypt (339%) showed a prominent rise in mortality rates. GBD data showed 16 countries had an increasing pattern in DALY in both genders. According to age and period effects, there was a significant upward trend in incidence, mortality rates, and DALY. Findings highlighted the urgent need for improved prevention and treatment services, including expanding access to HIV testing, promoting safe practices, increasing antiretroviral therapy coverage, and supporting targeted interventions for high-risk populations.

HIV prevention in individuals engaged in sex work

PURPOSE OF REVIEW

People who sell sex remain at disproportionate risk of acquiring HIV and should be prioritized for evidence-based HIV prevention programmes delivered at sufficient scale and intensity for effectiveness. Although new biomedical tools are becoming available, many basic lessons learned early in the HIV pandemic remain salient today and need renewed attention.

RECENT FINDINGS

New preexposure prophylaxis formulations, distribution systems, and delivery mechanisms are being successfully trialled and implemented, adding to well established prevention tools such as male and female condoms and lubricants. The importance of social support networks and community ownership of programmes has been consistently reaffirmed. Serious challenges remain in optimizing HIV prevention for sex workers, including providing services at the scale and intensity necessary for population level impact, addressing culturally sensitive issues of gender identity and sexual orientation, and protecting adolescents and young people who may sell sex. Pervasive social stigma, often reinforced by criminalization and police harassment, further constrain sex workers' access to available services and prevention tools.

SUMMARY

Meaningful community engagement and addressing the multiple social determinants of vulnerability at individual, community, and structural levels remain at the core of preventing HIV among people involved in selling sex.

Status of the HIV epidemic in key populations in the Middle East and north Africa: knowns and unknowns

The Middle East and north Africa is one of only two world regions where HIV incidence is on the rise, with most infections occurring among key populations: people who inject drugs, men who have sex with men, and female sex workers. In this Review, we show a trend of increasing HIV prevalence among the three key populations in the Middle East and north Africa. Although the epidemic continues at a low level in some countries or localities within a country, there is evidence for concentrated epidemics, with sustained transmission at considerable HIV prevalence among people who inject drugs and men who have sex with men in over half of countries in the region with data, and among female sex workers in several countries. Most epidemics emerged around 2003 or thereafter. The status of the epidemic among key populations remains unknown in several countries due to persistent data gaps. The HIV response in Middle East and north Africa remains far below global targets for prevention, testing, and treatment. It is hindered by underfunding, poor surveillance, and stigma, all of which are compounded by widespread conflict and humanitarian crises, and most recently, the advent of COVID-19. Investment is needed to put the region on track towards the target of eliminating HIV/AIDS as a global health threat by 2030. Reaching this target will not be possible without tailoring the response to the needs of key populations, while addressing, to the extent possible, the complex structural and operational barriers to success.