"Big Events" and HIV Transmission Dynamics: Estimating Time Since HIV Infection from Deep Sequencing Data Among Sex Workers and Their Clients in Dnipro, Ukraine.

Background: Major geopolitical events and structural shocks are thought to play a significant role in shaping HIV epidemics by influencing individual behaviours, reshaping social networks, and impacting HIV prevention and treatment programs. Here, we describe individual-level measures of estimated time since HIV infection (ETI) from viral next-generation sequencing data among female sex workers and their clients in relation to significant geopolitical events in Ukraine.

Methods: The Dynamics Study is a cross-sectional integrated biological and behavioural survey conducted among female sex workers and their clients in Dnipro, Ukraine (December 2017 to March 2018). We were able to successfully sequence a portion of the HIV gene on dried blood spot specimens among = 5/9 clients and = 5/16 female sex workers who tested positive for HIV (total = 10/25) using an in-house drug resistance genotyping assay. The "HIV EVO" Intrapatient HIV Evolution web-based tool was used to infer ETI from viral diversity.

Results: The median ETIs for female sex workers and their clients were 5.4 years (IQR = 2.9, 6.6) and 6.5 years (IQR = 5.4, 10.8), respectively. Nearly all HIV acquisition events ( = 7/10; 70%) were estimated to have occurred between the Great Recession (2008-2009) and the War in Donbas (May 2014-February 2022). In general, ETI suggests that HIV acquisition occurred earlier among clients (2012 [IQR = 2007, 2013]) compared to sex workers (2013 [IQR = 2012, 2016]).

Conclusion: Our findings suggest that most HIV acquisition in this small subset of female sex workers and clients living with HIV occurred during periods of economic decline. Molecular studies on timing of HIV acquisition against timing of major geopolitical events offer a novel way to contextualize how such events may shape transmission patterns.