Your baby can either die from hunger, or you can risk giving him HIV. Which do you choose?

This was the decision facing Dumsile, 32, a mother in Velebantfu, rural Swaziland. She's HIV positive. She took medication during pregnancy to prevent transmission to her son, Bouginkosi, but now he has HIV all the same.

"I breastfed him," says Dumsile. "I knew he could get HIV because of that, but I didn't have any food to give him, so I didn't have a choice."

I've come to Swaziland to gather stories for Caritas Internationalis' HAART for children campaign.

In 2007, 800 children were dying daily from AIDS-related diseases, mostly in poor countries.  We want to urge governments and pharmaceutical firms to improve methods to prevent mother to child transmission (PMTCT) and develop better testing and more child-friendly medicines for children with HIV and TB (a major opportunistic infection in people with HIV) in poor countries.
At 26 percent, Swaziland currently has the highest HIV prevalence in the world, according to UNAIDS.

Dumsile has already lost one child to a suspected AIDS-related illness. She is one of a group of 40 women I meet in Velebantfu who have HIV and whose children are also infected. Many of their men have already died from complications from AIDS.

Thabisile, 37, takes me up a long rough track to the remote mud hut where she lives with her 12-year-old daughter. I'm out of breath from the effort in the heat. A persistent cough rattles Thabisile's lungs as we walk. She has TB.

"I went to get tested for HIV because two of my children had died," Thabisile tells me through a translator.

A third child died from an AIDS-related illness, even though he was getting treatment, as well as her husband.

Nutrition is vital for people with HIV. Without it, ARVs are less effective and people's immune systems weaken - putting them at risk of an opportunistic infection.

Thabisile tells me she has had "sour porridge" made from maize for breakfast. That's all she eats most days. The spring near her house has dried up, so she only has water when she has money to buy it.

You need water to take HIV medication. Also, some of the children's medicines are in powder form and need to be mixed with water.

How does Thabisile afford to go to hospital to collect her monthly antiretroviral (ARV) treatment if she often hasn't got enough money for food and water?

She tells me that she can't always afford the 30 rand (around 2.60 euro) bus fare to the hospital, which is around 30 miles away, so sometimes she skips treatment. However, last month she was already at the hospital when it was time for her ARVs because she was visiting her brother, who had HIV, but who has since died.

Caritas community carer for the area, Grace Ntshangase, tells me that people in Swaziland didn't become aware of the risks of HIV until around 2002.

"Before that, if sores appeared on a person's body or they fell ill, they thought they were the victim of witchcraft," she says. I'm also told that because the King of Swaziland has many wives, it is culturally acceptable to have multiple partners.

Back in South Africa, I visit the Thabang Society in Parys, Free State. Caritas provides the treatment and counselling centre with ARVs. Because of a budgetary problem in Free State, there's been a critical shortage of ARVs from government-funded programmes.

In South Africa, 5.7 million people out of a total population of 47 million are estimated to be living with HIV.

Seeing as South Africa is relatively wealthy, I imagine that food and water aren't an issue for poor people with HIV. I'm wrong.