Community prevalence of blood-borne viruses (hepatitis B and HIV) in Ireland.

Background: Chronic infection with hepatitis B virus and HIV causes significant morbidity and mortality. Effective antiviral treatment is available for both. Ireland has historically been considered a low prevalence country. However, with increasing inward migration and diversity, this may be changing.

Aims: The aim of this study was to measure the community prevalence of hepatitis B virus and HIV infections in Irish residents born between the years 1965 and 1985.

Methods: Anonymised residual serum samples from blood tests ordered by community general practitioners and tested in eight general hospital laboratories, spread across Ireland, were analysed for the presence of Hepatitis B surface antigen and antibodies to HIV.

Results: A total of 6080 samples were analysed for hepatitis B surface antigen including 2993 males, 2807 females and 280 samples for which gender was not recorded. HBsAg was detected in 28/6067 samples giving an estimated prevalence of 0.46% (95% CI 0.32-0.67%). Antibodies to HIV were identified in 18/6064 giving an estimated prevalence of 0.33% (95% CI 0.19-0.47%). The prevalence of both hepatitis B and HIV was significantly higher in Cork (Southwest Ireland) than other centres: hepatitis B (12/1050 vs 16/5017, p = 0.014) and HIV (11/1049 vs 7/5015, p < 0.001).

Conclusions: The prevalence of hepatitis B virus and HIV infections in this cohort appear to be higher than previously estimated. In addition, their prevalence in the Cork area appears particularly high. Whether this represents a true prevalence or a chance finding will require confirmatory studies.