Concurrency and HIV transmission network characteristics among men who have sex with men with recent HIV infection

Abstract

Objective

Sexual partner concurrency is common among men who have sex with men (MSM) and may increase the probability of HIV transmission during recent (acute or early) infection. We examined the relationship between concurrency and HIV transmission network characteristics (proxies for HIV transmission) among MSM with recent HIV infection.

Design

Observational study integrating behavioral, clinical, and molecular epidemiology.

Methods

We inferred a partial HIV transmission network using 986 HIV-1 pol sequences obtained from HIV-infected individuals in San Diego, California (1996-2015). We further analyzed data from 285 recently HIV-infected MSM in the network who provided information on up to three sexual partners in the past three months, including the timing of intercourse with each partner. Concurrency was defined as sexual partners overlapping in time. Logistic and negative binomial regression were used to investigate the link between concurrency and HIV transmission network characteristics (i.e., clustering and degree or number of connections to others in the network) among these MSM.

Results

Of recently HIV-infected MSM (N=285), 54% reported concurrent partnerships and 54% were connected by ≥1 putative transmission link to others (i.e., clustered) in the network (median degree=1.0; interquartile range: 0.0-3.0). Concurrency was positively associated with HIV transmission network clustering (adjusted odds ratio=1.83, 95% confidence interval [CI]: 1.08-3.10) and degree (adjusted incidence rate ratio=1.48, 95% CI: 1.02-2.15)

Conclusions

Our findings provide empirical evidence consistent with the hypothesis that concurrency facilitates HIV transmission during recent infection. Interventions to mitigate the impact of concurrency on HIV transmission may help curb the HIV epidemic among MSM.