Last Sunday , 14 June, was the World blood donor day. A day which basically leaves many gay with a bitter aftertaste There as  a gay person can not be a Blooddonor according to Student filmmaker at the a university in Belgium Roland Javornik (26) 

Gay men are not allowed to donate blood in Belgium. In response to the AIDS crisis of the 1980's any man who has had sex with another man since 1977 is banned from giving blood. This 1985 provision argued that men who have sex with other men are at higher risk of contracting and transmitting HIV and hepatitis, posing a health risk to potential recipients. Thus, even with a needed rare blood type, gay men are prohibited from donating blood.
 

Take a look at the Trailer from the movie ‘For this is my blood’ through YouTube:

According to the local Red Cross the reason  is that the No of Gay men infected with HIV is still rising.

Remarkable however is that with an additional  procedure methylene blue filter, both hiv, hepatitis B and C can be destroyed which leaves clear plasma. ( This according to the student saying)

Methylene blue filter

The inactivation of viruses by methylene blue (MB) photoactivation is a new technology which is going to be introduced into the process of the fresh frozen plasma separation in order to improve the viral safety of this blood component. At the present time one has only to mention human blood and blood transfusion to elicit anxiety related to fear of somehow contracting AIDS (Acquired Immunodeficiency Syndrome) from tainted blood. While it is true that various antibody-based and other tests have made it possible to remove the vast majority of HIV (Human Immunodeficiency Virus, the causative agent of AIDS) infected blood from our blood supply, the current status of AIDS as an incurable fatal disease makes even a relatively small risk unacceptable to many.
 

Sources: Facebook and patentstorm.us

Anyone knows what the standpoint of the Thai Red Cross is about this??