Sixty-nine year-old Enifa Ngulama has sold some honey. She runs to the back of her mud-brick house in the village of Kasarika in southern Malawi to get a jar for a passerby. A neighbour sits on Enifa's porch and laughs at the elderly lady breaking into a trot. The sale is made, and the two neighbours sit down for a chat.

Enifa's relationship with the other people in her community wasn't always as amiable as this. Until recently, Kasarika had one of the highest rates of HIV in the south-east African country, more than double the national average of 12 per cent. One in four people knew they were HIV positive in Kasarika, but more did not know, and the real figure was undoubtedly much higher.

Every day the local vicar held at least four funerals, sometimes more. The village was dying. With no knowledge of how the virus was transmitted, the villagers looked for someone to blame. So they blamed the elderly, including Enifa.

The community – like so many others across Malawi – believed that HIV/Aids deaths were caused by a curse from God. They believed that curse was cast by witches. And a witch was anyone who lived to be "very, very old" or in local parlance, anyone over the age of 60.

Malawi's life expectancy is just 48.3 years. There are only 14 countries with a worse life expectancy, including Afghanistan, Sierra Leone and Somalia. Malawians were therefore suspicious of those who managed to make it to old age.

"Instead of rejoicing that God had kept us this far, when people died, other people pointed their fingers at me and said I was bewitching them," Enifa told The Independent. "It went on for years. In the end the whole village was accusing me. They used to say, 'You are a witch. You are killing people.' It was very painful. I just couldn't believe it."

Worse was to come. Enifa's own family turned on her. They ransacked her house shouting, "Why aren't you dead yet? We want you to die", she says.

"If your own children and grandchildren rise against you, what will happen to everyone else?" she says. The answer was that they joined in. Enifa was repeatedly attacked and on one occasion an angry mob carrying sticks set upon her, apparently intending to beat her to death, before she was rescued.

Eighty-one year-old Billy Thomas and his 73-year-old wife Ulalia also know what this feels like. The three of them were among some 40 elderly people in the village long held to be witches.

When one of Billy's grandchildren died of Aids, his family froze him out accusing him and Ulalia of causing the death by placing a curse on the child.

"It was a double calamity," he says. "We were grieving for our grandchild at the same time and grieving at the rejection… when someone accuses you of something that you haven't done it is very degrading."

"It was like being in prison. We stayed indoors as we were too afraid to go out," he says.

Like the rest of the village, Billy and Ulalia are self-sustaining farmers. Staying indoors meant they were slowly starving, though they say the "psychological attack" was worse than the hunger. They say no-one spoke to them at all for three years.

Two-thirds of all people of living with HIV/Aids are in Africa. The terrible effect on those of working age, who often leave orphans to be brought up by others, is well-known. But this is a hidden side to the HIV/Aids pandemic in Africa.

But one woman in Kasarika decided this had to change. Having attended an Aids-awareness training scheme called the Good Samaritan programme, run by the Bible Society of Malawi, Hilda Ntiya, 46, returned to Kasarika fired up to help her neighbours.

"I couldn't keep quiet," she says. "Without this training the village would have been wiped out. People thought they were bewitching each other. When they saw someone who was sick, they believed that it was from witchcraft.

"The prevalence rate was going up and up. People accused of being witches were beaten. It was a bad place to live. But not now. Now people understand that it isn't the case that people are witches. HIV is an illness. People know that now."

The scheme uses the biblical story of the Good Samaritan as its foundation, teaching compassion for those suffering. It explains what HIV/Aids is, how it is transmitted and encourages sexual gratification within marriage as a means of faithfulness, a reduction in the number of sexual partners, the importance of using of condoms and of getting tested. Over 365,000 people have heard this message over the last three years.

Two years ago, Hilda set up a one-room orphanage-cum-community centre in Kasarika, despite living on the poverty line herself. Every day she feeds 45 elderly people who were accused of witchcraft including Billy, Ulalia and Enifa. It gets them out, and helps them reintegrate into the village.

'Things have started to change," says Enifa. "In some cases people came to apologise to me. They said, 'We're very sorry. We know that you have nothing to do with the deaths that have happened'."