In the tumult of HIV, love also finds its place. Her name is Malehlohonolo and she was born HIV-negative on 28 April last year, even though both her parents are HIV-positive.

In 2008, the toddler's 32-year-old father, police officer Lehlohonolo Nkesana, tested positive at a clinic in Lesotho, in southern Africa. "I had fallen ill. I had constant headaches," he said. "At the hospital where they admitted me, they said: 'How about a test?' I decided to do it, and it came back positive. I told my wife and she went for a test and we found, well, that we are both positive. We talked a lot and we decided that, here we are, life has to go on."

In conversations with members of a peer support programme, mothers2mothers, run by the government of Lesotho, the Nkesanas learned that their HIV status need not necessarily be an obstacle to their having a third child. "We had two boys who were born before the HIV," said Qenehelo, 31, "but we really wanted a girl."

The couple's decision to have unsafe sex so as to conceive was controversial. Doctors used to advise people who are HIV-positive not to have unsafe sex with one another, for fear they could be reinfected. However, recent research suggests that if two partners have the same strain of HIV, the virus is transmitted only when the viral load is high. Patients who start on antiretrovirals soon after their HIV diagnosis can therefore often keep their viral load undetectable, thus minimising the danger of transmission. If the woman takes a course of antiretrovirals during pregnancy, the baby is almost certain to be born HIV-negative.

The Nkesanas sought advice from their local hospital. Lehlohonolo said: "We were told, 'OK you can have a baby, but you should wait a bit.' At the time my CD4 count was only eight. So we waited until the time was right. Malehlohonolo has now been tested negative three times."

The couple said their happy experience had been entirely the result of asking questions in the peer support group and seeking advice from medical professionals. But Lehlohonolo added: "The problem in Lesotho is that men do not get tested or seek advice. Mothers2mothers happens every Wednesday at the hospital, and it is a lively place. But fathers2fathers does not have so many members."