Background In France, men who have sex with men (MSM) are permanently excluded from blood donation. This policy is felt to be discriminatory by MSM activists. Furthermore, the policy is not fully respected because some MSM do not report their sexual behaviour before donating.
Methods We estimated the fraction of the current risk of HIV attributed to MSM. We then constructed a model based on data obtained from behavioural and epidemiological surveys to assess the impact of a new strategy in which MSM would only be deferred if they report more than one sexual partner in the last 12 months.
Results Thirty-one HIV seroconversions occurred among repeat donors between 2006 and 2008, giving a risk of one in 2 440 000 donations. Fifteen of these seroconversions (48%) were MSM. If all MSM had abstained from donating blood, the risk would have been 1 in 4 700 000 donations, half the current risk. The new strategy would result in an overall HIV risk of between 1 in 3 000 000 (close to the current risk) to 1 in 650 000 donations (3·7 times higher than the current risk).
Conclusions Changing the current MSM deferral policy may increase the risk of transfusion–transmission of HIV. However, this does not take into account a possible better compliance with MSM with a less stringent policy that would be perceived as more equitable. Conversely, relaxing the policy could encourage some MSM to seek an HIV test in blood centres. Thus, further qualitative study is needed to assess possible changes in compliance linked to a new policy.