A 20-year-old woman has been convicted of infecting her boyfriend with HIV during sex, knowing she had the infection.
The woman knew she had HIV nine months into the relationship
Cardiff Crown Court heard the woman, who cannot be named to protect the man's identity, had sex with him for 10 months knowing she was HIV positive.
She admitted unlawfully inflicting grievous bodily harm and was sentenced to two years' youth detention.
The court was sent a letter by the man who said his life had been ruined.
The court heard that she had lied to her partner when he asked her if she carried the infection.
The woman - who was 18 at the time of the offence and had had HIV since the age of 15 - said she did not tell him because she feared that if she told him, he would leave her.
The court heard the couple had protected sex after they met in a nightclub in September 2002, but stopped using condoms when they moved in together shortly afterwards.
They split up early in 2004 because he suspected she was sleeping with other men, and he then began hearing rumours about her HIV status, the court was told.
He confronted his ex-girlfriend but, said Andrew Jones, prosecuting, "she blatantly lied to him and told him not to be so stupid".
The court heard she showed him a report which said that she was not HIV positive, but the man now believes it was doctored to show a negative result.
She had, in fact, known she was HIV positive since June 2003, the court was told.
'First proper girlfriend'
The man discovered he was HIV positive 10 days before Christmas 2004 after undergoing tests.
In a letter read to the court, the man said: "I now have to live with being infected with HIV for the rest of my life.
"I will never forget the day I went to the clinic with my father and my brother and they told me I was HIV positive. I can never forgive her for what she has done and the terrible pain my family is going through.
"My mum didn't like her from the start but I was 18 years old and she was my first proper girlfriend and I had to learn from my own mistakes. And learn I did - the hard way."
After her arrest, the woman told police she had heard it was difficult for a man to catch the infection from a woman.
In a letter which was also read out in court, the woman told the man: "I know I hurt you but I didn't know how to tell you. I'm really, really sorry.
"I just didn't want to believe I had HIV. I was 15 when I slept with a boy but I thought it was love.
"I just hoped and prayed you wouldn't catch it. I know it was a horrible thing to do."
In sentencing the woman, Judge Llewellyn Jones told the woman: "In my judgement, what you did to that man is so serious that only a custodial sentence can be justified."