(P46) Impact of the COVID-19 pandemic on HIV and syphilis screening and case characteristics in British Columbia, Canada: an Interrupted Time Series Analysis

Tuesday, July 25, 2023

16:00 – 18:00 CST

Primary Presenter(s)

Elaine Chan, MPH, CPH (she/her/hers)

Epidemiologist
BC Centre for Disease Control
Vancouver, British Columbia, Canada

Co-author(s)

VR

Venessa Ryan, MSc

Senior Epidemiologist
BC Centre for Disease Control, British Columbia, Canada
MO

Michael Otterstatter

BC Centre for Disease Control, United States
TC

Teddy Consolacion

BC Centre for Disease Control, United States
OM

Olga Mazo

BC Centre for Disease Control, British Columbia, Canada
MM

Michael Macneil

BC Centre for Disease Control, Canada
MM

Muhammad Morshed, PhD

Clinical Professor
Department of Pathology and Laboratory Medicine
Vancouver, British Columbia, Canada
AJ

Agatha Jassem

BC Centre for Disease Control, United States
LH

Linda Hoang

British Columbia Centres for Disease Control Public Health Microbiology & Reference Laboratory, United States
TG

Troy Grennan, MD

Physician Lead, HIV//STI Program
BC Centre for Disease Control
Vancouver, British Columbia, Canada
JW

Jason Wong

Medical Director, Clinical Prevention Services
BC Centre for Disease Control, Canada

Background: The COVID-19 pandemic disrupted sexual health services and impacted sexual and health-seeking behaviours. This study’s objective was to examine the impact of the COVID-19 pandemic on syphilis and HIV screening and infectious syphilis and HIV case characteristics in British Columbia (BC), Canada.

Methods: Monthly HIV and syphilis test episodes (30-day window; extracted from the BC Centre for Disease Control Public Health Laboratory) and confirmed HIV and infectious syphilis cases (extracted from provincial surveillance systems) in BC from January 1, 2018 to June 30, 2022 were examined. Analysis periods were: 1) Pre-Pandemic (January 2018-February 2020); 2) Pandemic – Initial Restrictions (April 2020); and 3) Pandemic – Subsequent Restrictions (June 2020-June 2022; following gradual re-opening in May 2020). March 2020 and May 2020 were excluded as transition periods. Segmented regression was used to assess level and trend changes in syphilis and HIV screening. Chi-squared tests were used to compare monthly percent positivity (number of infectious syphilis cases/number of syphilis test episodes x100%) and case characteristics between periods.

Results: During Initial Restrictions, screening levels immediately decreased 56% for HIV (incidence rate ratio [IRR] = 0.44 [95% CI: 0.41-0.48, p< 0.0001) and 66% for syphilis (IRR = 0.34 [95% CI: 0.31-0.37, p< 0.0001]). In the Subsequent Restrictions period, screening levels partially recovered though remained below counterfactual levels. Mean monthly percent positivity decreased for HIV from 0.05% (range: 0.03-0.09%) Pre-Pandemic to 0.01% (p=0.041) and 0.04% (range: 0.02-0.06%; p=0.007) for the Initial and Subsequent Restrictions periods, respectively, while increasing for syphilis from 0.42% (range: 0.28-0.58%) to 0.67% (p< 0.001) and 0.64% (range: 0.34-0.91%; p< 0.0001). Compared to Pre-Pandemic, a higher proportion of infectious syphilis cases were diagnosed in the secondary stage during both pandemic periods (p=0.014 Initial Restrictions; p< 0.0001 Subsequent Restrictions). More infectious syphilis cases were diagnosed with neurosyphilis during Subsequent Restrictions (3.6%) compared to Pre-Pandemic (2.1%) (p=0.002), while no difference was observed during Initial Restrictions (2.1%).

Conclusion: In BC, HIV and syphilis screening declined due to the COVID-19 pandemic and had not returned to projected levels by June 2022. Our findings suggest decreased screening for infectious syphilis may have delayed diagnoses amidst increasing community transmission.