Feasibility and acceptability of using biometric fingerprinting to track migrations and support retention in HIV prevention research in fishing population in East Africa.

Introduction: Fishing populations constitute a suitable key population amongst which to conduct HIV prevention trials due to very high HIV prevalence and incidence, however, these are highly mobile populations. We determined the feasibility and acceptability of using fingerprinting and geographical positioning systems to describe mobility patterns and retention among fisherfolks on the shoreline of Lake Victoria in South-western Uganda.

Methods: Between August 2015 and January 2017, two serial cross-sectional surveys were conducted during which fingerprinting of all residents aged 18-30 years on the shoreline of Lake Victoria was done. A mapper moving ahead of the survey team, produced village maps and took coordinates of every household. These were accessed by the survey team that assigned household and individual unique identifiers (ID) and collected demographic data. Using the assigned IDs, individuals were enrolled and their fingerprints scanned. The fingerprinting was repeated 6 months later in order to determine the participant's current household. If it was different from that at baseline, a new household ID was assigned which was used to map migrations both within and between villages.

Results: At both rounds, over 99% accepted to be fingerprinted. No fingerprinting faults were recorded at baseline and the level was under 1% at round two. Over 80% of the participants were seen at round two and of these, 16.3%, had moved to a new location whilst the majority, 85%, stayed within the same village. Movements between villages were mainly observed for those resident in large villages. Those who did not consider a fishing village to be their permanent home were less likely to be migrants than permanent residents (adjusted odds ratio = 0.37, 95%CI:0.15-0.94).

Conclusion: Use of fingerprinting in fishing populations is feasible and acceptable. It is possible to track this mobile population for clinical trials or health services using this technology since most movements could be traced within and between villages.