Eurosurveillance - Volume 26, Issue 47, 25 November 2021

Despite availability of pre-exposure prophylaxis (PrEP), the incidence of HIV-1 in Europe remained stable the past decade. Reduction of new HIV-1 infections requires more knowledge about the profiles of high-risk transmitters and late presenters (LP).

We aimed to investigate risk factors associated with HIV-1 transmission clusters and late presentation with HIV-1 in Denmark.

Blood samples and epidemiological information were collected from newly diagnosed HIV-1 patients between 2009 and 2017. We genotyped pol genes and performed phylogenetic analyses to identify clusters. Risk factors for clustering and LP were investigated with partial proportional odds and logistic regression. Covariates included transmission mode, HIV-1 subtype, age, origin and cluster activity.

We included 1,040 individuals in the analysis, 59.6% identified with subtype B and 48.4% in a cluster. Risk factors for clustering included Danish origin (odds ratio (OR): 2.95; 95% confidence interval (CI): 2.21–3.96), non-LP (OR: 1.44; 95% CI: 1.12–1.86), and men who have sex with men (MSM). Increasing age and non-B subtype infection decreased risk (OR: 0.69; 95% CI: 0.50–0.94). Risk for late presentation was lower for active clusters (OR: 0.60; 95% CI: 0.44–0.82) and Danish origin (OR: 0.43; 95% CI: 0.27–0.67). Non-Danish MSM had a lower risk than non-Danish heterosexuals (OR: 0.34; 95% CI: 0.21–0.55).

HIV-1 transmission in Denmark is driven by early diagnosed, young, subtype B infected MSM. These may benefit most from PrEP. Non-Danish heterosexual HIV-1 patients could benefit from improved communication to achieve earlier diagnosis and treatment.

Knowing the factors associated with HIV transmission is necessary in order to design preventive programmes tailored to the epidemiological situation in each region and population.

Our objective was to study the sociodemographic, clinical and behavioural characteristics of men who have sex with men (MSM) who were newly diagnosed with HIV infection.

We carried out an observational, descriptive, study on all MSM newly diagnosed with HIV infection in one clinic for sexually transmitted infections (STI) and HIV clinic in Madrid between 2014 and 2019. Information on sociodemographic, clinical, and behavioural characteristics of participants per year of diagnosis was collected.

We detected a total of 1,398 people with HIV infection, 253 of whom were recent seroconverters (rSCV) with a median duration of documented seroconversion of 6 months. From the total, 97.9% infections were sexually transmitted and 2.1% involved injected drugs, i.e. slam practices. The average age was 32.9 years (range: 15.6–74.9), 51.8% were Spanish and 40% Latin American. These diagnoses decreased in Spanish people and increased in Latin Americans during the study period. Of the rSCV, 73.9% had condomless sex under the influence of drugs and 28.9% participated in chemsex sessions. Apps were used by 92.6% rSCV for sexual encounters and 70.4% of them attributed HIV transmission to their use.

Combination of HIV prevention strategies, as pre-exposure prophylaxis, should be reinforced among young MSM, especially those born in Latin America, those who use drugs for sex, and those who use apps in search of sexual contacts.

In Europe, HIV disproportionately affects men who have sex with men (MSM), people who inject drugs (PWID), prisoners, sex workers, and transgender people. Epidemiological data are primarily available from national HIV case surveillance systems that rarely capture information on sex work, gender identity or imprisonment. Surveillance of HIV prevalence in key populations often occurs as independent studies with no established mechanism for collating such information at the European level.

We assessed HIV prevalence in MSM, PWID, prisoners, sex workers, and transgender people in the 30 European Union/European Economic Area countries and the United Kingdom.

We conducted a systematic literature review of peer-reviewed studies published during 2009–19, by searching PubMed, Embase and the Cochrane Library. Data are presented in forest plots by country, as simple prevalence or pooled across multiple studies.

Eighty-seven country- and population-specific studies were identified from 23 countries. The highest number of studies, and the largest variation in HIV prevalence, were identified for MSM, ranging from 2.4–29.0% (19 countries) and PWID, from 0.0–59.5% (13 countries). Prevalence ranged from 0.0–15.6% in prisoners (nine countries), 1.1–8.5% in sex workers (five countries) and was 10.9% in transgender people (one country). Individuals belonging to several key population groups had higher prevalence.

This review demonstrates that HIV prevalence is highly diverse across population groups and countries. People belonging to multiple key population groups are particularly vulnerable; however, more studies are needed, particularly for sex workers, transgender people and people with multiple risks.