2011 Vanuatu Integrated Bio-Behavioural Survey and population size estimation

In most Pacific Island countries and territories (PICTs), the populations that are identified as most-at-risk of exposure to HIV and STIs are those that have been consistently identified as being at higher risk of exposure to HIV and STI in other settings, such as sex workers, men who have sex with men (MSM) and injecting drug users and prisoners.

Despite this, there is no empirical evidence on HIV and STI epidemiology and vulnerability in most PICTs, including Vanuatu. There is also no information about the number of people in these population groups.

This project - a partnership between the Burnet Institute, Wan Smolbag Theatre, and the Vanuatu Ministry of Health - aims to contribute towards the improvement in the quality of HIV and STI responses for the most-at-risk populations in Vanuatu (namely sex workers and MSM).


  • To estimate the number of MSM and sex workers in Port Vila
  • To estimate the prevalence of HIV and other STIs (chlamydia, gonorrhoea, syphilis) and risk behaviours of people in these groups through Integrated Bio-Behavioural Survillance.


A combination of methods will be used to estimate the population size of sex workers and MSM. This includes asking members of the population groups to make an estimate, use of the nomination method until saturation is met, and using capture-recapture. These are commonly used methods to estimate the population of hard-to-reach groups.


Participants in the IBBS will be recruited by peer researchers from Wan Smolbag via Respondent Driven Sampling (RDS). In RDS, participants are nominated by their peers rather than being selected randomly or by convenience (ie: being in the same place).

Recruitment in an RDS study starts by recruiting seeds, and then recruiting his or her friends or partners, and then his or her partners, and so on. Each participant will be asked to nominate three of their peers.






This study is a partnership between the Burnet Institute, Wan Smolbag Theatre and the Vanuatu Ministry of Health.


This project has been funded by the Secretariat of the Pacific Community (SPC) under the Response Fund Stream 4 - Competitive Grant.

Contact Details

For any general enquiries relating to this project, please contact:

Professor Margaret Hellard AM

Deputy Director (Programs); Adjunct Professor, Monash University, DEPM.




[email protected]