Abstract

We read with interest the article by Hunter et al., in which they argue that “hidden” social network members are crucial in understanding behavior change and suggest that public health interventions can harness social networks, including those that are “hidden."1 While it is generally true that "hidden” social networks “have typically been overlooked, unobserved, and subsequently underused” in public health, there are examples in harm reduction-focused work with people who inject drugs (PWID) where individuals and their social networks have been trained to facilitate behavior change that aims to limit the transmission of blood-borne viruses.2 We have been exploring this concept of social network analysis through a cohort study of PWID and HCV transmission in Melbourne, Australia, over the past 10 years,3 and also believe there are lessons to be learned in developing behavior change interventions. (Am J Public Health. Published online ahead of print April 16, 2015: e1. doi:10.2105/AJPH.2015.302667).