Background: In August 2005, the Canadian Blood Services decreased the deferral period for tattooing and ear or body piercing from 12 to 6 months. This study assessed the impact of this change on blood safety and availability.
Study design and methods: The prevalence of these activities was assessed on an anonymous mail-out survey of 40,000 recent donors. Transmissible disease (TD) marker rates were calculated using the National Epidemiology Donor Database. A case-control study was performed comparing risk factors in TD-positive donors with matched controls. Donor deferral rates were assessed before and after the change in deferral period.
Results: The prevalence rates of tattoo, ear piercing, and body piercing were 13.7, 53.6, and 10.4 percent in survey respondents, respectively, with up to 0.7 percent of activity likely to represent deferrable risk. TD marker rate was low and stable at 21.6 per 100,000 donations before and 19.2 per 100,000 donations after the change in deferral length. Remote tattoo was associated with hepatitis C virus (HCV) risk (odds ratio, 5.43; 95% confidence interval, 1.82-16.2), but neither recent tattoo nor piercing was a risk factor for HCV or hepatitis B virus. Shortening of the deferral period reduced deferrals by 20 percent for tattoo and 32 percent for piercing.
Conclusion: There was no measurable adverse effect on safety and a positive but less than expected effect on blood availability after shortening the deferral period for tattoo and piercing. The length of other temporary deferrals should be reassessed, since their current contribution to blood safety may be negligible.