Theme: Epidemiology & Public Health Research Year: 2024
Background:
Glasgow has been experiencing an HIV outbreak among people who inject drugs since 2015. Previous research highlighted that in Glasgow city centre, HIV prevalence increased by 10-fold between 2011-12 and 2017-18, and low rates of HIV testing hindered efforts to control the outbreak. Key drivers of HIV infection include homelessness, cocaine injecting and public injecting. The objectives of this study were to: (1) assess changes in HIV prevalence in Glasgow city centre, neighbouring areas (rest of Glasgow) and the rest of Scotland since 2017-18, and (2) quantify risk factors in the later stages of the outbreak.
Methods:
Four national cross-sectional bio-behavioural surveys conducted in Scotland between 2011-12 and 2019-20 (n=8,265). HIV prevalence was assessed by region of recruitment (Glasgow city centre; rest of Glasgow, and rest of Scotland) and outbreak period (pre-outbreak: 2011-14; ongoing outbreak: 2017-18 and 2019-20). Risk factors for HIV infection in Scotland were assessed during the ongoing outbreak period (2017-20). Multi-variate logistic regression was undertaken.
Results:
HIV prevalence plateaued in Glasgow city centre in 2019-20 (11.3%) compared to 2017-18 (10.3%) (aOR=1.04, 95% CI 0.59 to 1.84, p=0.886). However, prevalence in the rest of Glasgow continued to rise in 2017-18 (2.3%) and 2019-20 (4.0%), compared to 2011-14 (0.5%) (aOR=6.15, 95% CI 2.49-15.17, p<0.001; aOR=9.27, 95% CI 4.02-21.38, p<0.001, respectively). HIV prevalence remained relatively stable (0.5-0.7%) across periods for the rest of Scotland. Preliminary analyses suggest that transactional sex is a newly identified risk factor for HIV infection in the ongoing outbreak period (2017-20) (aOR=1.77, 95% CI 1.63-1.92, p<0.001).
Conclusions:
HIV transmission has plateaued in Glasgow city centre but is increasing in rest of Glasgow; and our findings highlight the importance of increasing HIV testing in neighbouring areas. Future work should focus on assessing the impact of the COVID-19 pandemic on HIV transmission associated with the outbreak.