Like so many young mothers in this country, Vicki Achieng, 35, is a widow. Her husband died of AIDS two years ago. He left her a vegetable farm and five young children to help her work it.

"Life is very difficult without a husband, you know?" she explains wistfully, her lilting Luo accent tinged with sadness. "I miss him so much!"

Achieng knew even before her husband died that he had infected her with HIV. "So many people have it, and so many people are living with it," she shrugs. "We cannot run from it. We are coping with it."

She had little choice but to accept her fate and raise her children. She could not possibly afford the expensive antiretroviral medicines that could keep her HIV disease in check, and even if she could, there was nowhere to get them, no doctor to prescribe them.

Then she heard about a new clinic in Kisumu, not far from the rocky shores of Lake Victoria in western Kenya's Nyanza province. The clinic, set up by doctors from UCSF and the Kenya Medical Research Institute, is having a dramatic impact - "literally resurrecting the dead," says Charles Muga, one of the Kenyans who works there. The clinic has become a model of how to finally reverse years of spiraling AIDS death rates in sub-Saharan Africa - a model that the U.S. government is ready to replicate throughout Kenya.

It took two hours, but Achieng made the arduous journey from her remote farm - by bicycle taxi and then a crowded, dusty van, across bumpy, pockmarked, red clay roads - to the Lumumba Health Center in Kisumu, where the UCSF doctors confirmed that Achieng was HIV-positive.

Full range of services

She started sobbing softly - not because she had HIV, but because the doctors told her that not only did the clinic have an ample supply of antiretroviral medicines, but they also were hers, for free, as soon and as long as she needed them.

"This clinic is saving my village," Achieng says. Before it opened, "people suffered. And most of the people died."

This clinic, and another like it in Nairobi, was conceived by Dr. Craig Cohen, 47, a professor of obstetrics, gynecology and reproductive sciences at UCSF. Five years ago, Cohen created Faces - Family AIDS Care and Education Services - with Dr. Elizabeth Anne Bukusi of the Kenya Medical Research Institute.

It started as a research project, but since then, Faces has served more than 75,000 Kenyans such as Achieng at its own clinics and about 60 others operated by Kenya's Ministry of Health and supported by the Faces team.

The program is financed largely by the President's Emergency Program for AIDS Relief, which began under President George W. Bush. It also relies on private philanthropy, including money from the Bill and Melinda Gates Foundation.

Spread across western Kenya, the Faces-staffed clinics provide HIV testing and counseling and a full range of prevention and treatment services, including preventing HIV transmission from mother to child during pregnancy. The clinics also serve as a valuable research platform for scholars from UCSF and Kenya.

'Tide is definitely turning'

Cohen and Bukusi have applied for, and are anticipating, another round of federal funding that would allow significant expansion of the Faces program.

"Our number of patients could at least double," Cohen says. "And we would be able to expand our service area," perhaps bringing HIV care closer to Achieng and other patients living in more remote areas.

Bukusi hopes new support from the Obama administration will help Faces achieve the World Health Organization's goal of universal access, "meaning serving at least 80 percent of HIV patients who need care within our service areas."

Cohen has been working in Kenya since 1994 and has been commuting between San Francisco and western Kenya for much of the past decade.

"I've always had this focus of helping those individuals who are less fortunate than me ... underserved populations," he says. "The tide is definitely turning."

Since Faces opened its first clinic in Kisumu, the prevalence of HIV among young women ages 15 to 24 has been cut in half - from 20 percent to 10 percent. That's still inordinately high - in the United States, roughly half of 1 percent of the population is infected with HIV - but it's a dramatic improvement.

"People are changing their behaviors," Cohen says. "Condom usage is up."

Vital training for Kenyans

Prevention, not treatment, is the key to ending the AIDS scourge that continues to ravage sub-Saharan Africa, he says.

"We're not going to be able to treat ourselves out of this epidemic," Cohen says during a recent visit to the Lumumba clinic in Kisumu. "Probably in Kenya, for every one person who's being initiated in care and treatment, there are probably three individuals who are being infected with HIV, every day."

Kenya has the fourth-highest AIDS death rate in the world. Nationwide, the HIV infection rate is a little over 7 percent - but in Nyanza, it can top 30 percent in the hardest-hit areas.

The Luo people, including President Obama's paternal family, dominate this western province. It's a land of dire poverty and extreme polygamy, both of which contribute to one of Africa's highest rates of HIV and AIDS.

Cohen and his team, which includes 10 other doctors and staffers from UCSF, are determined to train the Kenyans to lead their own country out of the epidemic. They've hired more than 400 local people to staff the clinics. Local Luos, not San Franciscans, reach out to the community to spread the word about using condoms, circumcising males and testing for HIV.

It's not always an easy task. In the town of Migori, 115 miles south of Kisumu, a lanky 102-year-old Luo known locally as "Danger" Akuku is revered for his vast family - he has had 42 wives and 200 children. He has outlived several of his wives, who died of AIDS. His latest bride is just 19 years old. What would compel this teenager, and her family, to consent to such a marriage?

"The man is very rich, with many, many cows," says Samuel Ndolo, who's in charge of community engagement for Faces at Migori District Hospital. "He is very, very tall and very strong. He is legendary."

And somehow, Ndolo says, Danger has remained AIDS-free. "It is a miracle."

On the outskirts of Kisumu, there are few such miracles. On Lake Victoria, Africa's largest lake, fishermen catch tilapia and Nile perch and move from beach to beach to sell their fish. When they beach their boats and empty their nets, they catch - and spread - something else.

Trading fish for sex

The fishermen trade fish for sex with the female fishmongers who come to the beach to buy the day's catch. Twenty-five percent of the men are infected with HIV. On some of the lake's islands, the prevalence is even higher.

"Each fisherman has a woman on each beach," says Jeremiah Ochieng, a sociologist with the Kenya Medical Research Institute. "And there are 32 beaches!"

The women load their fish onto trucks for transport to market - and then the truck drivers demand sex as payment, too. These cultural traditions are difficult to overcome, but Ochieng is trying. He's been distributing condoms and testing a male microbicide. Slowly, the behavior of the fishermen and the women who work the beaches is changing, although the HIV prevalence remains stubbornly high.

"I know we will get to the point where we can clear HIV from the surface of the globe," Ochieng says. "It has been very, very good working with the developed world, with the people from San Francisco, to help Africa come out of this situation. Things have really changed here."

Trying to cut new infections

Cohen knows that for many Kenyans, the outlook is still bleak. Children as young as 5 or 6 are turned out on the street to become family breadwinners, and some of the girls sell sex to make a living. Eight-year-olds responsible for administering HIV drugs to their younger siblings show up at the Migori pharmacy to collect their meds. Many men refuse to get tested for HIV themselves, only to banish their wives when they test positive.

Still, hope isn't as rare as it might seem in Nyanza province.

"I think we're really making headway here," Cohen says. "But my goal is not just to make headway and make a small difference. It's really to bring the number of new infections down as close to zero as possible while providing care and treatment" to as many people as possible.

Back at the Lumumba clinic in Kisumu, Achieng is full of hope after her visit with the American doctors. Smiling through her tears, she focuses on the future of her family and of her small farm. To her great relief, all of her children have tested negative for HIV.

Even though she knows she has the virus, she is optimistic and thinking about finding a new partner. "It is not difficult" to get a new husband, she laughs. "Oh, men are so easy to convince! We women have all the power."

Maybe not, says Samuel Ndolo of Faces' Migori operation, but he says Achieng's reaction is typical of those helped by the UCSF team and their Kenyan colleagues. "We've changed lives. I see lives of people changing in a big way, and that makes me and everybody who works here very, very happy."