Every year, Canadian Blood Services (CBS) collects approximately 900 000 units of blood from across Canada. In order to promote the safety of the blood recipients, CBS has instituted exclusion criteria for certain donors. Currently, men who have sex with men (MSM) can only donate after a deferral period of five years after their last sexual contact with a man. We believe that, in light of advances in medical technology and shifting social values, this deferral period needs to be re-assessed. We believe that a change to a 1-year deferral is necessary.
The deferral policy for MSM was put in place in 1983 as a lifetime ban, and then changed to a 5-year deferral in 2013. This policy was justified by the increased prevalence and incidence of HIV among MSM, and a several tragic contaminations of the national blood supply in the 1970s. Banning high-risk groups from donating was arguably the best method of protecting the blood supply at this time.
However, the situation today is radically different than it was at the implementation of this policy. The demographics of HIV have changed dramatically (in 2011, for example, heterosexual contact accounted for 37% of new infections). Furthermore, screening tools for blood donations have improved tremendously, and now have a sensitivity and specificity between 99 and 100%. Nucleic acid testing has reduced the window period from 3-6 months to 2-3 weeks, further improving testing. Risks of contaminated blood entering the blood supply are now so low that they cannot be measured directly, but must be calculated with mathematical models. With a change to a 1-year deferral, the additional risk would still be well below the currently accepted threshold for risk in the blood supply.
Internationally, several similar policies have been put in place. The UK and Australia, among others, have recently implemented 1-year deferral policies, while Italy, Mexico, and Spain use individual risk stratification with no specific deferral for MSM. Since these new policies were adopted, the data collected in these countries show that there is no increased risk of HIV contamination of the blood supply compared to a 5-year or lifetime deferral, and hence no increased risk to blood recipients. Furthermore, research conducted in Australia has demonstrated an almost perfect compliance (99.7%) with the new policy by MSM. Though we believe that individual risk assessment and the end of any form of discrimination against the MSM population by blood bank should eventually be considered, there is currently not enough data to support the safety of this policy.