Living Positive follows six HIV-positive people, each of them on the same day, in six different parts of the world.
Twenty-five-year-old Pheap has been a sex worker in Cambodia for six years, meeting clients in the grounds of the capital's famous Wat Phnom.
NOTE ADDED: 4 MAY 2006
Sadly, Pheap died on 2 May 2006. She passed away "beautifully and peacefully" in hospital in Cambodia.
She has a hard life, sleeping rough, often without enough food to eat and forced by financial difficulties to give up her daughter for informal adoption.
She now faces the emotional and health difficulties of being HIV-positive.
Despite all of this, she is a buoyant, optimistic woman, often smiling and often attentive to the needs and problems of the other sex workers in the park.
She is a fighter and remains determined to survive.
Pheap was born in a very small and poor village in Pusat Province in 1981.
Having to support her family from a young age by digging and selling potatoes, Pheap never had any formal education.
When she was 10 years old her father died and her mother remarried a man who had three children of his own.
Finding the living arrangements and poverty difficult, Pheap left for Phnom Penh in 1998 without telling anyone.
Alone, desperate to earn money, and with little chance of finding other employment in Phnom Penh, Pheap turned to prostitution in Toul Kork (one of the red light districts in Phnom Penh) as a means of survival.
She left Toul Kork in 2002 and became a bar girl and informal sex worker in bars regularly attended by foreigners.
"I was desperate for money," she says. Tourists asked me not to use condoms to protect myself and I agreed. I didn't know they were HIV-positive."
Renting a room at the time with her partner and father of her child in Kandal Market, she sent money home to her ill mother.
Abuse and adoption
In early 2003, Pheap returned to the village to see her mother, but sadly she had already passed away.
Around the same time, Pheap and her daughter left the child's father because he beat her continuously if she did not bring home enough money from prostitution.
"He abused drugs, drank and had sex with other women. I arrived home at one and two in the morning after sleeping with a client.
"He only thought that I received a lot of money. If I earned below $15 (£9), I would be beaten. I would not be in trouble if I could make over $50 (£30), if I slept with clients for a whole night. He beat me everyday."
After contracting the virus from one of her clients, Pheap lost her job as a bar girl and is now part of a group of girls who make their living as street prostitutes.
Many are HIV positive and help each other survive. Unable to look after her daughter, Pheap has had to leave her with a friend in another part of the city.
"I love my child very much but I cannot afford to look after her," she says. "If I have her with me then both of us would go hungry and she'd become ill as a result.
"Giving her away is better for her, even though I really love her."
At present, Pheap is recovering from a bout of stomach TB, caught because her immune system has been weakened by the HIV.
She attends a local charity for homeless young people to have a medical check-up.
Although Pheap is optimistic and understands the importance of staying positive, she did not always feel this way.
"I feel happy now. Before I didn't listen to the doctor. I threw away the medicine. I didn't care about my life. Now I try to take the medicine for my future," she says.
"I try not to get angry or worry. If I do, I will get weaker and the disease will get worse. So I try to stay cheerful all the time. "
Living Positive was broadcast on Thursday, 1 December, 2005 on BBC Two at 2100 GMT.
A debate featuring the six people filmed for the programme was broadcast on Friday, 2 December, 2005 on BBC Four at 1900 GMT.