Short Communication: HIV-1 Transmission Networks Across South Korea

Abstract

Molecular epidemiology can help clarify the properties and dynamics of HIV-1 transmission networks in both global and regional scales. We studied 143 HIV-1-infected individuals recruited from four medical centers of three cities in South Korea between April 2013 and May 2014. HIV-1 env V3 sequence data were generated (337-793 bp) and analyzed using a pairwise distance-based clustering approach to infer putative transmission networks. Participants whose viruses were ≤2.0% divergent according to Tamura-Nei 93 genetic distance were defined as clustering. We collected demographic, risk, and clinical data and analyzed these data in relation to clustering. Among 143 participants, we identified nine putative transmission clusters of different sizes (range 2-4 participants). The reported risk factor of participants were concordant in only one network involving two participants, that is, both individuals reported homosexual sex as their risk factor. The participants in the other eight networks did not report concordant risk factors, although they were phylogenetically linked. About half of the participants refused to report their risk factor. Overall, molecular epidemiology provides more information to understand local transmission networks and the risks associated with these networks.

Keywords: HIV transmission network; HIV-1 env V3 sequence; South Korea.

FIG. 1.

Location of study sites and the putative transmission networks. Shaded circles represent each study sites and participants within identified putative transmission networks. The black line shows the potential transmission. Edge lengths and circle size are optimized for visual presentation and do not represent genetic distances between putative transmission partners. One gray point indicates one patient.

FIG. 2.

A phylogenetic tree with V3 sequences of participants. Gray line indicates putative transmission networks that have genetic distance <2.