Unsuppressed HIV viral load among people living with HIV by exposure category in British Columbia, Canada from 2005 to 2020: a population-based cohort study.

BACKGROUND

Maintaining a suppressed HIV plasma viral load (pVL) is critical to the optimal management of people living with HIV (PLWH), and to prevent HIV transmission. We examined trends and determinants of unsuppressed pVL among PLWH from April 2005 to March 2020 in British Columbia (BC), Canada by HIV exposure groups.

METHODS

We analyzed data from all PLWH in BC identified in a provincial database linking testing, treatment, laboratory, pharmacy and administrative health data. For each year, individuals were classified as having an unsuppressed pVL if they were newly diagnosed, had any pVL ≥ 200 copies/mL test result, or had no pVL measurement. We used univariate generalized estimating equations (GEE) to examine trends over time and multivariate GEE modelling to examine factors associated with unsuppressed pVL.

RESULTS

PLWH in BC increased from 5712 in 2005 to 8012 in 2020, and the proportion of those with pVL ≥ 200 copies/mL decreased from 66.4% to 18.1% (p < 0.0001, test of trend). Those who were people who inject drugs (PWID) (adjusted odds ratio [aOR] = 1.92; 95% CI 1.77-2.08) and those with only heterosexual exposures (aOR = 1.16; 95% CI 1.07-1.26) or other exposures (aOR = 1.23; 95% CI 1.06-1.42) had increased odds of unsuppressed pVL, compared with men who have sex with men (MSM). Unsuppressed pVL was also associated with female gender identity (p = 0.0109), first CD4 cell count result (p = 0.0085), year of ART initiation, health authority residence, hepatitis C seropositivity, and younger age at diagnosis (p < 0.001 for all).

CONCLUSIONS

The proportion and number of PLWH with unsuppressed pVL in BC fell signficantly over a 15-year period, with different trends by HIV exposure categories. Those who are PWID, females, and youth may require additional supports to be retained in effective HIV care.