Quantifying unmet prevention needs among MSM in Europe through a multi-site bio-behavioural survey

Introduction: The HIV epidemic represents an important
public health issue in Europe particularly among
men who have sex with men (MSM). Global AIDS
Monitoring indicators (GAM) have been widely and
jointly promoted as a set of crucial standardised items
to be adopted for monitoring and responding to the
epidemic. Methods: The Sialon II study, implemented
in 13 European cities (2013-14), was a complex multicentre
integrated bio-behavioural cross-sectional
survey targeted at MSM, with a concomitant collection
of behavioural and biological (oral fluid or blood
specimens) data. Rigorous sampling approaches for
hard-to-reach populations were used (time-location
sampling and respondent-driven sampling) and GAM
indicators were calculated; sampling frames were
adapted to allow weighted estimates of GAM indicators.
Results: 4,901 MSM were enrolled. HIV prevalence
estimates ranged from 2.4% in Stockholm to
18.0% in Bucharest. When exploring city-level correlations
between GAM indicators, prevention campaigns
significantly correlated with levels of condom use
and level of HIV testing among MSM. Conclusion: The
Sialon II project has made an important contribution
to the monitoring and evaluation of the HIV epidemic
across Europe, integrating the use of GAM indicators
within a second generation HIV surveillance systems
approach and in participatory collaboration with
MSM communities. It influenced the harmonisation of
European data collection procedures and indicators
via GAM country reporting and contributed essential
knowledge informing the development and implementation
of strategic, evidence-based HIV prevention
campaigns for MSM.