Doctors exist not just to serve patients, but to serve their community, whether they define that as a nearby neighborhood, an entire city, or, for Dr. Rajeev Venkayya, the whole world.

Today, Venkayya returns to the Northeastern Ohio Universities Colleges of Medicine and Pharmacy (NEOUCOM), from which he graduated in 1991, to tell graduating doctors-to-be that being a physician means not just treating patients, but caring for society.

This is not a platitude from Venkayya. He walks his talk, serving as the director of global health delivery at the Bill & Melinda Gates Foundation, where he hopes to cure — or at least treat — health-care inequality suffered by the world's disadvantaged populations.

The foundation's efforts are wide-reaching, focusing on safer childbirth practices, development of new vaccines, increased use of existing vaccines, methods to reduce the spread of HIV/AIDS, such as male circumcision, and other disease-fighting tools already common in developed countries.

''Millions of people — most of them children — die each year in developing countries from diseases that are preventable and treatable,'' the foundation says on its Web site. ''Moreover, tragically little research is done to prevent or cure some of the world's biggest killers, such as malaria and tuberculosis.''

Venkayya's career took the course of a typical medical school graduate. After a residency, he began seeing patients, eventually becoming co-director of the medical intensive care unit at San Francisco General Hospital and founder/director of the hospital's high-risk asthma clinic.

But a White House fellowship in 2002 made him question whether he could have an impact beyond San Francisco. He said the experience showed him how proper decision-making and good public policy can have a positive impact on people's lives — a lot of them — more than he would ever

be able to affect as a doctor.

He stayed on at the White House for five more years, the last 21/2 as senior director for bio-defense for the Homeland Security Council, as well as special assistant to President Bush on bio-defense. He dealt with such issues as bird flu, SARS, pandemic planning, disease surveillance, and the possible medical consequences from weapons of mass destruction.

Venkayya, who graduated from the University of Akron before attending NEOUCOM, moved to the Gates Foundation in January.

Throughout his childhood, Venkayya witnessed how the world's disadvantaged live, traveling to India to visit family. He has since visited sub-Saharan Africa, Bangladesh, and Pakistan.

''Since my earliest days I've seen inequalities and disparities first-hand,'' he said. ''These are things I've thought about for a long time.''

His personal experience makes him appreciate one of the foundation's guiding principles all the more: ''All lives have equal value.'' Where you're born, he said, should not determine how — or how young — you die.

The other guiding principle is ''To whom much is given, much is expected.''

And that's what he wants today's graduates to understand.

Being a physician means caring for patients, but it also means ''maintaining a commitment to service beyond the examination room or the hospital in which we work.''