It’s not usual to offer a dedication at the top of an article, but I feel the need to do so here. This is for Perry Nyama and Leah Chimbali. Perry was a man so cool in the bush that I would face a charging elephant with him. In fact, I did. Leah’s fax machine kept me in touch with home on a long trip: a woman of kindness, generosity and good vibes.

Both are dead now. Both died of what is called, with desperate humour, “a slow puncture”. That is to say, as a result of Aids. Their deaths could have been postponed for years. But there was no one there to do the postponing.

Now I can tell the story of the vision of two extraordinary women: a vision made far more effective by the power of two wheels and an engine. This is Aids and the Art of Motorcycle Maintenance.

Those of us who live in the developed world can imagine what it is to be without food, clean water or shelter, but a lack of transport simply doesn’t occur to us. In Kenya, for most people, ten miles is a long, fearsome and exhausting journey. Mostly, you walk. If you are in funds, in some areas you can travel by boda-boda, a bicycle taxi. Women ride sidesaddle with babes in arms. It follows, then, that if you are ill and 10 miles from the nearest place that can assist you, you are in trouble.

“I am happy – and I am fat.” Priscilla Imani got a laugh for this. But it was a laugh of agreement, of fellowfeeling, of shared achievement. To be happy and fat after being miserable, reviled, rejected and wasting away is nothing less than a triumph.

“I am HIV positive,” she said. These women have made this once earth-shattering declaration so many times now that there is not even a hint of defiance about it. “Before I knew I was HIV positive I was very ill, and my people ran away from me. The hospital said it was malaria. I was stigmatised. My son would not speak to me. He would not let me see my grandchildren. But then I went to Vumulia.”

Vumilia is one of Africa’s small miracles. It is not much of a place, in worldly terms: a few rented rooms, concrete walls, a bit of a yard. But it’s like the Tardis: the inside is vast. The physical dimensions are small; the spiritual dimensions immense. And it is one woman’s vision.

I was greeted with soaring African harmonies. A group of African matrons were singing a song of welcome. They then introduced themselves, one by one: I am a widow; I have two children; three children; four; I am HIV positive.

Vumilia is partly an orphanage. Many of the children are HIV positive. It is also a place where people can come for testing and counselling and, as a result, is surrounded by fear and suspicion from the outside; strength and confidence from within.

Imani was tested and found positive. She received counselling and help. She learnt that the condition can be lived with. Some treatments are available from the hospitals. With support, she set despair aside and got on with living. “We all thought we were going to die tomorrow,” she said. “Now I want to be trained to ride a motorcycle.”

Beatrice Sajita can ride a motorbike all right. Two months ago, she couldn’t even ride a bicycle. Now, most days, she goes roaring off round the bush. There was a ditch and a ludicrously steep slope into Doreen Shitamdidi’s place. Sajita took it like Evel Knievel.

She wouldn’t have reached Shitamdidi’s place without the bike. Well, not without a day’s walk. Shitamdidi is a widow with four children. She is HIV positive. Sajita visited her. “I was very weak, and I was stigmatised,” Shitamdidi said. She was looked down on because she was a widow; because many believed she had brought about the death of her husband.

It’s bad enough being ill but to be blamed for it as well makes it very hard. “Because of Vumilia, I was educated in how to live with HIV,” Shitamdidi continued. “I became a home-based carer and now I visit clients myself and teach them hygiene and knowledge of HIV.”

Baba Musi Mimimi is a client of hers; a dignified but difficult old boy. “Now I don’t feel alone,” he said. “She gives me advice, she tells me to eat, to take my medicine three times a day. I call her my daughter.”

Rose Moon is one of those rare people who believe that they must shoulder responsibility for the ills of the world. A Kenyan, trained as a psychologist, she returned from Nairobi for a Christmas visit to the community she had been brought up in and it was a Damascene experience. A widow with HIV and three children approached her diffidently and asked for advice.

Moon had been suffering from depression. “I was longing to be with someone who would listen.” She identified at once with the isolation of the HIV-positive women. She started Vumilia, which means, in Kiswahili, perseverance.

Since then she has waged a war on ignorance, shame and isolation. She brought knowledge, self-worth and health. And now she does so by motorcycle. She has five counsellors, three of them women, all of them HIV positive. And they brave the wild African roads to take Vumilia’s powerful weapons into the community. Because of the motorcycles, Vumilia’s relevance has increased. In Africa transport is power.

Ngwarate Mashonga is a Zimbabwean motorcycle nut. He is also a fervent believer in the gospel of maintenance. He works for Riders for Health, which is one of The Times Christmas charities this year. Africa is full of vehicles donated by charities and foreign aid organisations, bodies that have not thought things through. Africa is knee-deep in vehicles that don’t work because no one had been trained to maintain them. They are abandoned for problems as trivial as dirt in the carburettor. Mashonga is determined to establish a culture of vehicle maintenance in Africa, and not as a male mystery, either.

Rosemary Ayuma Mini and Susan Mgeresa prepare to travel out to meet their clients by inspecting the lubrication, adjusting the chain, going through all the checks before roaring off to empower the stricken. This is a long-term project. The human beings and the machines are both in for the long haul.

Ann Lurie is Moon’s sister in miracles, a fellow bringer of motorcycle-powered miracles. There are differences. Moon is African, black and running a shoestring operation. Lurie is blonde, American and loaded. But they are both reaching out across wild and inhospitable country, bringing hope and belief on two wheels. And like Moon, Lurie did so after a Damascene experience.

Lurie is a philanthropist of a hands-on kind. She came to Kenya on safari and ended up starting a school. She was there for the opening day and observed that there was a greater problem than education. Half the children were ill. So she founded an ultra-modern clinic in the heart of Masai territory.

She was advised: “You have to downgrade your vision of a Cadillac into a Chevy.”

“You mean I should give these people half-good healthcare?”

She doesn’t. Aid Village Clinics centre at Mbirikani is an island of medical modernity in the endless expanse of countryside. But how to get the benefits of modern healthcare out across the fearsome roads; sometimes a bouncing, punishing surface hard as rock; and sometimes, all too rarely alas, flooded?

There are 16 community health workers, a fleet of motorcycles, a workshop and it reaches out to 561 HIV patients. Not that the clinic treats only HIV. That is just the great inescapable problem.

John Kaseenchi is one of the mounted community health workers at Mbirikani. We followed him on his rounds, bouncing about in an ancient Land Cruiser while he roared ahead on his bike, stopping every now and then to let us catch up.

Sitote came out to greet us, face alight. As is the way for a Masai child, he bowed. You rest a hand briefly on his head. Sitote is five, an Aids orphan, HIV positive himself. He lives with his grandmother and she couldn’t cope because Sitote was very ill. He had diarrhoea and there was a problem in getting the right treatment, partly because the grandmother would not accept that he was HIV positive. (He may have had the condition at birth or acquired it through breast-feeding before his mother died.)

But the breakthrough was made, and Sitote got well. So this visit was more a case of human maintenance than emergency treatment. Besides, Kaseenchi wanted to check that the latrine provided by the clinic was actually being used. Well, there were no cobwebs, the path to the place showed no signs of being overgrown, there was fresh water available for ablutions. These things have become status symbols.

Here, all was good, everyone was cooperative, everything was progressive. Sitote showed us where he kept his medicines and how he took them. “As soon as they are rational we explain why he must take them and the risks of not taking them,” Kaseenchi said.

The grandmother showed Kaseenchi that she now has a separate hut for cooking, so that Sitote doesn’t have to inhale smoke from the fire all the time. This was hope for the hopeless all right; hope in the middle of the bush. And the beacon of hope was parked right outside the hut.

“And what do you want to be when you grown up, Sitote?”

“Motorcycle rider.”

CVC Capital Partners, the private equity group, will match all donations made to Riders for Health through The Times Appeal