Epidemiology. 2021 Jun 7. doi: 10.1097/EDE.0000000000001390. Online ahead of print.
ABSTRACT
BACKGROUND: The speed with which a pathogen circulates in a sexual network is a function of network connectivity. Cross-sectional connectivity is a function of network features like momentary degree and assortative mixing. Temporal connectivity is driven by partner acquisition rates. The forward-reachable path has been proposed as a summary measure of these two aspects of transmission potential. We use empirical data from San Francisco and Atlanta to estimate the generative parameters of the forward-reachable path and compare results to the HIV/sexually-transmitted infection (STI) epidemics in each city.
METHODS: We used temporal exponential random graph models to estimate the generative parameters for each city’s dynamic sexual network from survey data. We then simulated stochastic dynamic networks from the fitted models and calculated the forward-reachable path for each realization, overall and stratified by partnership type and demographics.
RESULTS: The overall mean and median paths were higher in San Francisco than in Atlanta. The overall paths for each city were greater than the sum of the paths in each individual partnership network. In the casual partnership network, the mean path was highest in the youngest age group and lowest in the oldest age group, despite the fact that the youngest group had the lowest mean momentary degree and past-year partner counts.
CONCLUSIONS: The forward-reachable path by age group revealed additional utility of the measure beyond the temporal and cross-sectional network connectivity measures. Other non-network factors are still necessary to infer total epidemic potential for any specific pathogen.
PMID:34172692 | DOI:10.1097/EDE.0000000000001390