Combining Molecular Network Analysis and Field Epidemiology to Quantify Local HIV Transmission and Highlight Ongoing Epidemics.

Objectives: This study aimed to establish a collaborative approach to quantify local HIV transmission, which is an issue of great concern to public health. Methods: We linked HIV-1 pol gene sequences to demographic information and epidemiological investi-gations in Hangzhou (a central city in East China). We estimated local acquisition rates from a collabora-tion of molecular network analysis (with a distance-based approach) and epidemiological investigations. Results: Among 1064 newly diagnosed patients with HIV, 857 pol sequences were acquired and sub-sequently analyzed. Multiple subtypes were identified, with circulating recombinant form (CRF)07_BC (42.5%) and CRF01_AE (39.2%) predominating, followed by 13 other subtypes and 26 unique recombinant forms. By integrating the molecular network analysis and epidemiological investigations, we estimated that the proportion of local infection was 63.2%. The multivariable analyses revealed that individuals in clusters were more likely to be local residents, be aged 50 years or older, work as farmers, and have a higher first cluster of differentiation 4 count level ( P < 0.05). The proportions of local acquisitions over 70% were observed in local residents (79.9%, 242/303), individuals aged 50 years or older (73.6%, 181/246), and farmers (75.6%, 99/131). Conclusion: The molecular network analysis can augment traditional HIV epidemic surveillance. This study establishes a paradigm for quantifying local HIV transmission for generalization in other areas.(c) 2022 The Author(s). Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )