A lifetime ban on gay and bisexual men from giving blood is under review, following calls from campaigners that the policy is unfair and misplaced. So which groups are prevented from donating on grounds of sexual behaviour?

The public is often being urged to give blood, to help those that need it, but the adverts are not directed at those deemed too high-risk to donate.

Blood services expect a shortfall in supply this winter
People are banned from giving blood for a variety of health reasons such as having had a blood transfusion after 1980 or having a family member with CJD. But rules which govern giving blood simply because of who you have sex with are not universally accepted by those who are banned.

A man is prevented from giving blood if he has ever had sex with another man, even if that happened decades ago and he has recently tested negative for sexually transmitted diseases like HIV.

A woman who once worked as a prostitute is also banned for life from donating, while anyone who has had sex with anyone who has been sexually active in parts of the world with high HIV rates, like sub-Saharan Africa, cannot donate for 12 months.

A review is under way to look again at these rules. The government's advisory committee on the safety of blood, tissues and organs (SaBTO) is holding a public consultation meeting in London as part of that process.
THE ANSWER

• Lifetime bans apply to men who have had sex with other men as well as prostitutes and intravenous drug users
• If you have sex with any of the above groups, you are banned for 12 months
• Although there are four different blood services across the UK, the same rules apply and they will all be subject to the findings of the advisory committee, if its recommendations are followed.

According to those rules, the following groups are among those that have a lifetime ban on giving blood:

• any man who has had sex with another man, even safe sex using a condom
• anyone who has ever worked as a prostitute
• anyone who has injected themselves with drugs - even once
• anyone who has ever had syphilis, human T-lymphotropic virus, hepatitis B or C
• Potential donors are also banned for 12 months after having had sex with:

a man who has had sex with another man (if you're a female)

• a prostitute
• anyone who has ever injected themselves with drugs
• anyone with haemophilia or a related blood clotting disorder, who has received clotting factor concentrates
• anyone of any race who has been sexually active in parts of the world where Aids/HIV is very common
• And there are shorter term restrictions on people who have visited malarial areas.

WHAT ARE THE RULES ABROAD?

• Gay men banned:
• Most EU countries, US and Canada (if gay sex took place after 1977)
• Not banned (with caveats): Spain, Italy, Australia, Hungary, New Zealand, Argentina, Japan, South Africa
• The National Blood Service for England and North Wales says it has to exclude groups known to present a particularly high risk of blood-borne viruses, to reduce the risk of infected blood entering the blood supply.

Although all blood is screened, a small number of infected donations may be missed because there is a period of time between getting the infection and the test showing a positive result, its guidelines say.

Condoms reduce the risk of infection but don't eliminate it, they say, and men who have sex with men account for 63% of HIV diagnoses where the infection was likely to have been acquired in the UK. The risk of HIV-infected blood entering the blood supply would increase five-fold if the ban was lifted.

WHO, WHAT, WHY?

A regular part of the BBC News Magazine, Who, What, Why? aims to answer some of the questions behind the headlines

But gay rights campaigner Peter Tatchell says a government that opposes homophobic discrimination cannot possibly uphold the ban.

"It is based on the stererotyped, irrational, bigoted and unscientific assumption that any man who has had oral or anal sex with another man - even just once 40 years ago with a condom - is high risk for HIV. This is nonsense.

"The truth is that most gay and bisexual men do not have HIV and will never have HIV. Their blood is safe."

A spokesman for the Department of Health said the committee would publish its findings in 2010.