Seroprevalence and demographic factors associated with hepatitis B, hepatitis C and HIV infection from a hospital emergency department testing programme, London, United Kingdom, 2015 to 2016

BACKGROUND: Progress towards HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV) elimination requires local prevalence estimates and linkage to care (LTC) of undiagnosed or disengaged cases. AIM: We aimed to estimate seroprevalence, factors associated with positive blood-borne virus (BBV) serology and numbers needed to screen (NNS) to detect a new BBV diagnosis and achieve full LTC from emergency department (ED) BBV testing. METHODS: During a 9-month programme in an ED in east London, England, testing was offered to adult attendees having a full blood count (FBC). We estimated factors associated with positive BBV serology using logistic regression and NNS as the inverse of seroprevalence. Estimates were weighted to the age, sex and ethnicity of the FBC population. RESULTS: Of 6,211 FBC patients tested, 217 (3.5%) were positive for at least one BBV. Weighted BBV seroprevalence was 4.2% (95% confidence interval (CI): 3.6–4.9). Adjusted odds ratios (aOR) of positive BBV serology were elevated among patients that were: male (aOR: 2.7; 95% CI: 1.9–3.9), 40–59 years old (aOR: 1.9; 95% CI: 1.4–2.7), of Black British/Black other ethnicity (aOR: 1.8; 95% CI: 1.2–2.8) or had no fixed address (aOR: 2.9; 95% CI: 1.5–5.5). NNS to detect a new BBV diagnosis was 154 (95% CI: 103–233) and 135 (95% CI: 93–200) to achieve LTC. CONCLUSIONS: The low NNS suggests routine BBV screening in EDs may be worthwhile. Those considering similar programmes should use our findings to inform their assessments of anticipated public health benefits.