News Release

A piece of the bigger picture: evidence on HIV prevalence among key populations in Europe

Systematic review published in Eurosurveillance ahead of World AIDS Day

Peer-Reviewed Publication

European Centre for Disease Prevention and Control (ECDC)

Marking World AIDS Day on 1 December, Eurosurveillance publishes an article that brings together evidence on HIV seroprevalence in five population groups  affected by HIV in the countries of the European Union and European Economic Area (EU/EEA): men who have sex with men (MSM), people who inject drugs (PWID), people in prison, sex workers and transgender people [1].

Sex between men is the main HIV transmission mode (39% in 2019) among newly reported diagnoses in the EU/EEA overall while injecting drug use accounted for 4% of all new diagnoses [2]. Over the years, many European HIV prevention and control measures consequently have been targeted towards MSM and PWID in the attempt to address their higher risk for HIV and other sexually transmitted and blood-borne infections.

HIV in key populations: lack of routine data
Alongside these two population groups, prisoners, sex workers and transgender people have a similar risk due to structural, legal, social, economic, behavioural and biological factors. In addition, there is no standardised way of collecting and including information on risk factors such as sex work or imprisonment in national surveillance data for these groups leading to a gap in the understanding of HIV epidemiology in those key populations across Europe.

In their systematic literature review, Stengaard et al. pooled peer-reviewed studies published during 2009–19 and identified 87 country- and population-specific studies from 23 countries for analysis. The resulting data were grouped by key population, presented in forest plots by country with simple or pooled (if two or more studies were identified) prevalence and 95% confidence intervals.

MSM and PWID combined both the highest number of studies and the largest identified variation in HIV prevalence, ranging from 2.4–29.0% (19 countries) for MSM and from 0.0–59.5% (13 countries) for PWID.

Among prisoner (nine countries) populations, prevalence ranged from 0.0–15.6% based on available data from the literature, and in sex workers prevalence ranged between 1.1–8.5% (five countries). For HIV prevalence in transgender people, only from one country data were retrieved, indicating a prevalence of 10.9%. Individuals belonging to several key population groups showed higher HIV prevalence.

Closing a knowledge gap
Given that more studies about MSM and PWID were identified, the authors outline a knowledge gap regarding HIV prevalence in the other population groups for many countries in Europe, with for example extremely limited published data on HIV prevalence among transgender people.

Stengaard et al. conclude that Our results complement other available data sources on the epidemiology of HIV in Europe, particularly HIV case surveillance data published at the European and national level, by providing additional information about HIV prevalence in key populations that are not covered as part of most routine case surveillance data (notably concerning prisoners, sex workers, and transgender people)’.


References/notes to editors:
[1] Stengaard Annemarie Rinder, Combs Lauren, Supervie Virginie, Croxford Sara, Desai Sarika, Sullivan Ann K, Jakobsen Stine Finne, Santos Quenia, Simões Daniel, Casabona Jordi, Lazarus Jeffrey V, de Wit John B F, Amort Frank M, Pharris Anastasia, Nerlander Lina, Raben Dorthe. HIV seroprevalence in five key populations in Europe: a systematic literature review, 2009 to 2019. Available from: (after 16:00 Central European Time on 25 November 2021)

[2] European Centre for Disease Prevention and Control (ECDC)/World Health Organization (WHO) Regional Office for Europe. HIV/AIDS surveillance in Europe 2020 – 2019 data. Available from:

[3] World AIDS Day was introduced by the World Health Organization (WHO) in 1988 and is observed annually on 1 December to raise awareness of the AIDS pandemic caused by HIV infection.

[4] HIV/AIDS: The human immunodeficiency virus (HIV) is a virus, which attacks the immune system and causes a lifelong severe illness with a long incubation period. The end-stage of the untreated infection, acquired immunodeficiency syndrome (AIDS), results from the destruction of the immune system. AIDS is defined by the presence of one or more “opportunistic” illnesses (other illnesses due to decreased immunity).

[5] Sustainable Development Goals (SDG) and 90–90–90 targets: in 2015, 17 Sustainable Development Goals (SDGs), each with specific targets for 2030, were introduced by the UN, including target 3.3 to end AIDS as a public health threat by 2030. In 2014, UNAIDS and partners launched the so-called ‘90–90–90 targets’ with the aim for 2020 that 90% people living with HIV are diagnosed (early) and 90% of those diagnosed receive antiretroviral treatment (ART), which leads to viral suppression among 90% of those on such treatment, i.e. the virus is no longer detectable in the blood. Such an undetectable viral load also means that HIV-positive people on effective treatment do not transmit the virus. The latest data on progress towards these 90-90-90 across Europe and Central Asia can be found here:

[6) More HIV-related articles in this week’s issue: 

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