The recent trial of Giovanni Mola, the Italian sentenced to nine years last week for "culpably and recklessly" transmitting HIV to his girlfriend, is the latest in a string of HIV-related convictions across the UK over the past six years.

The subject of extensive press scrutiny, the trial brings the criminalisation of HIV transmission to the forefront of public debate.

For many, the question is clear-cut - anyone responsible for passing a potentially fatal infection to another should be the subject of a criminal investigation.

For others, including a number of leading HIV/Aids organisations, prosecuting individuals living with HIV has the potential for doing more harm than good and could further isolate an already marginalised section of the community.

Mola is only the second individual to be convicted in Scotland, after Stephen Kelly received five years in jail in 2001 for passing the virus on to his girlfriend. The number of prosecutions south of the border has been much higher, currently totalling nine, with more cases under investigation.

The 38-year-old Italian found out that he had HIV three years before beginning a relationship with Miss X in 2003. Throughout their relationship he failed to disclose his status and Miss X only became aware she, too, was HIV positive when she went for testing after their relationship ended.

There are no rules when it comes to when and how much someone living with HIV should tell a sexual partner. As far as the law is concerned, full disclosure is the only real guarantee against prosecution for HIV transmission and failing to tell a sexual partner of your status can be a risky proposition.

However, for people living with the virus the situation is not quite as clear-cut. Many fear the rejection and stigma that is associated with telling a partner. An article from Positive Nation, an HIV and sexual-health magazine, advises people to prepare themselves for a partner to "run away, scream or cry" when they find out.

"If we were talking about a world where prejudice and discrimination didn't exist, disclosing your HIV status would be a very simple thing," says Vicky Field, policy offer of the Terrence Higgins Trust.

"Unfortunately, we don't live in that world. Where possible, disclosure is a good course of action - but there are particular situations where we have to think very carefully."

An HIV positive status is a personal matter for each individual and full disclosure to every sexual partner is not a likely reality, experts say.

"In one-night stands, there isn't always a lot of discussion about anything; names, addresses, marital status. Why should someone go into a big discussion about their HIV status?" asks Roy Kilpatrick, chief executive of HIV Scotland.

Many leading HIV/Aids organisations across the UK have been lobbying for a change in the law to enable prosecutions only when transmission is "intentional", excluding the current charge of "reckless" transmission.

When Deborah Jack, chief executive of the National Aids Trust, made this case last week, the Sun newspaper branded her views "astonishing".

Jack outlines the reasons her organisation is against prosecution for "recklessness". "One of our real public health concerns is sending out a message that it's OK to sleep with anyone and not use protection because if they're infected they have to tell you.

"Certainly, some of the anecdotal evidence about what's going on is people are terribly afraid of the implications of having an HIV status. Already there's a lot of stigma around HIV and this potentially gives another barrier to people coming forward."

None of those already convicted in the UK has been found guilty of intentionally transmitting the disease to their partners. The charge of "recklessness" covers people who don't take the proper measures to prevent transmission, such as disclosing status, or making sure all sex was protected.

In Scotland, Kelly and Mola were charged with "culpable and reckless conduct" under common law.

"Culpable meaning blameworthy," says Donald Findlay QC , who defended Kelly in 2001. "Blameworthy is a standard that the law views as being something more than careless."

Roy Kilpatrick, chief executive of HIV Scotland, takes the view that prosecutions in Britain have become a reality and that, although emphasis should be placed on the shared responsibility of both partners to ensure their sexual wellbeing, in some cases criminal action may be unavoidable.

"In the recent case, the young woman was quite aggressively told there was absolutely no reason to use a condom," he says of the Mola trial.

"What would happen if we had a major public campaign saying these cases should never have happened? It would be misunderstood totally by most of the public."

According to James Chalmers, senior law lecturer at Edinburgh University, prosecutions for reckless transmission should remain an exception rather than a rule. However, the potential for people to be charged should be protected.

"There's a pretty clear general legal rule that recklessly causing harm to other people is seriously wrong. If you said that there would be no legal cases you'd be carving out an exception and you'd have to have very strong grounds to be able to do so."

The law that Mola was prosecuted under does not just apply to HIV, and could apply to any other infection transmitted through sexual contact.

"As a matter of principle it would be my view that if you knowingly transferred even a minor sexually communicable disease, that too could be prosecuted as culpable and reckless conduct," says Findlay.

These prosecutions are a recent phenomenon and, though they remain relatively rare, show no signs of diminishing, particularly in England and Wales.

The Crown Prosecution Service is expected to issue guidelines for England and Wales outlining when it will and won't prosecute for transmission of HIV.

There are no equivalent guidelines expected in Scotland and the law will only become clearer, the more people stand in the dock.

What effect that will have on people's willingness to come forward for testing or disclose their status is a long way from being certain.

'It's like murder. You can't do that'
Stuart contracted HIV in 1991 from his wife, who didn't know when they started sleeping together that she was HIV positive.

"I had a negative test five times," he says. "We were having sex for six months before she found out she had the virus."

Ann, who contracted the virus in the same year, said she decided to get the test when she saw adverts on television.

William was diagnosed with HIV in 1983, after testing negative five times. He, too, got the disease from sexual contact.

Giovanni Mola
Both Stuart and William were strongly in favour of the prosecution of Giovanni Mola. Stuart said: "I think he was right to get jailed. HIV is like a jail sentence. It's the worst thing you can have."

William said: "It's like murder; you cannot go about doing that."

Changing attitudes to HIV
All three spoke of the days when HIV was a new phenomenon and the differing attitudes people held.

Stuart said: "I heard people saying I'm gonna go out and find a girl to sleep with, and I hope she gets it'."

They agree that times have changed and such attitudes are no longer widely held.

Ann: "At the start, no-one knew what was happening. People are wiser in this day and age."

Disclosure of HIV
Both men are adamant that they have informed every sexual partner about their status. Stuart said: "I tell everyone. There are a lot of women who have not gone with me because I have the virus."

William said: "I am open to everyone about it. On the gay scene they do not care."

Ann said: "It's heterosexuals that aren't open-minded. With them, HIV has still got a stigma attached. I do not think it will ever go away."

Stuart added: "Being gay and having HIV is 10 times worse. People have got to be more open-minded."

Will prosecutions deter testing?
William said: "If you are going for the first time to get tested, you are more worried about yourself than what might happen."

Ann was keen to emphasise that both partners should be careful to protect themselves when having sex: "You have to protect yourself. They might not be telling the truth, they might be lying. You have to look after yourself as well."