Methods and Lessons Learned around the World’ organised by the WHO Collaborating Centre for HIV Strategic Information was held from 30th May – 2nd June in Croatia. A team from Sri Lanka participated and comprised from Mr Suchira Suranga - Deputy Director (Monitoring and Evaluation) and Ms Nadika Fernandopulle GFATM Project Officer FPA Sri Lanka, and from the National STD/AIDS Control Programme Ms Sriyakanthi Beneragama (Consultant Epidemiologist), Sathya Herath (Public Health Specialist) and Ariyaratne Manathunge (Coordinator - Strategic Information). 

Reliable estimates of the size of populations at high risk for HIV are important for prioritizing target populations, planning HIV prevention services, measuring coverage with these services and monitoring and evaluation of interventions. The aim of the course was to provide participants with practical guidance on how to design studies to estimate the size of populations at higher risk for HIV (particularly female sex workers [FSW], people who inject drugs [PWID], men who have sex with men [MSM]), conduct these studies, and analyze, interpret and use the data. Participants were given an opportunity to share their own country-specific experiences and challenges in estimating the size of high-risk groups. As a post-programme action plan, a national level working committee consisting of the above participants together with the Director-NSACP and Executive Director-FPA Sri Lanka was established to design and implement the National Size Estimation of key population (NSE) and Integrated Biological and Behavioural Surveillance (IBBS) survey.