8981Phylogenetic surveillance of HIV epidemic control from 2014 to 2020 among MSM and heterosexual groups in Quebec


B. Brenner * (1), R.-I. Ibanescu (1), M. Oliveira (1), J.-P. Routy (2), R. Thomas (3), M. Roger (4), Montreal Primary HIV Infection Study Group (1) Lady Davis Institute, McGill AIDS Centre, Montreal, Canada, (2) McGill University Health Centre, Montreal, Canada, (3) Clinique M├ędicale l''Actuel, Montreal, Canada, (4) University of Montreal, Montreal, Canada


BACKGROUND: The UNAIDS 90-90-90 initiative has led to 38% declines in heterosexual (HET) epidemics in Africa since 2014. In 2019, The Ending the HIV Epidemic for America added phylogenetics as fourth pillar for epidemic control by 2030. Here, phylogenetics was combined with available epidemiological data to track drivers of HIV-1 spread among Men having Sex with Men (MSM), People Who Inject Drugs (PWID) and recent migrants.
METHODS: Phylogenetic analyses, using MEGA-10 and Microbe-TRACE methodologies, ascertained the linkage of sequences obtained from newly-diagnosed persons (2002'2020). Infections were stratified into groups according to HIV-1 subtype, sex, and cluster size, including i) the subtype B MSM epidemic (male singletons/male-male clusters); ii) the subtype B PWID epidemic (mixed gender large clusters); iii) subtype B HET infections originating from the Caribbean and Americas (female singletons, mixed gender clusters) and iv) non-B subtype epidemics originating outside Canada.
RESULTS: Amongst MSM, there were 56%, 43% and 27% declines in singleton, small (1-5 members) and large cluster networks (6-152 members) from 2014'2020 compared to 2007'2013. Epidemic control among MSM was thwarted by 35 super-spreader, large cluster micro-epidemics, adding 8'-96 infections/cluster from 2014-2020. Notably, 18 clusters gained 4-12 infections during the COVID 19 era (post-2019). The subtype B epidemic among PWID is controlled showing 54% declines in new infections from 2014-2020 compared to 2007-2013. Recent migration has led to the steady growth in the subtype B and non-B subtype HET epidemics. To date, 65% and 20% of HET epidemics were singletons or small clusters (2-4 members). PHI cohort data revealed that 28% of infected MSM born outside Canada acquired large cluster provincial variants. Of note, isolated non-B subtype HET outbreaks occurred in Quebec City, Richelieu, and Northern Quebec.

CONCLUSIONS: Declines in HIV-1 infections are promising. Public health measures must address emerging needs of vulnerable migrants and younger MSM populations.