Identifying Social-Epidemiological Roles Associated with Viral Exposure Using Regular Equivalence Blockmodeling

Identifying individuals at high risk of infection is critical to guiding interventions during infectious disease outbreaks. Network centrality can characterize infection risk, but its utility varies across pathogens and social systems. We used equivalence-based blockmodeling to identify social-epidemiological roles associated with viral exposure among 1,297 adults in northeast Madagascar. Roles were determined based on social networks derived from reported shared free time and exchanges of food and farmwork. We identified three distinct role categories, including individuals with many reciprocated social ties (Popular), individuals who sent many ties with few reciprocated (Hangers-On), and individuals who had few connections (Periphery). To assess whether the role categories covaried with viral exposure, we performed Phage ImmunoPrecipitation Sequencing with VirScan using dried blood spot samples to determine exposure to 337 virus species and subtypes. Individuals in the Popular (ß [95% CI]: 0.29 [-0.06-0.63]) and Hangers-On (ß [95% CI]: 0.36 [0.12-0.60]) role categories had greater viral exposure than individuals in the Periphery role category. Roles performed better at predicting exposure than single measures of centrality. Equivalence-based blockmodeling extends the utility of network centrality for characterizing infection risk and provides new insights into how social roles relate to both pathogen exposure and susceptibility to infection.