A new U.N. report shows that the global AIDS epidemic has been cutting a broad and destructive path, causing 3 million deaths in the past year alone, or 60,000 a week. Nearly half of the 40 million people living with HIV-AIDS are women, and more than 2 million are children. Infection rates are rising in nearly every region of the world.

Why, then, in the face of numbers such as these, are some public health officials, myself included, optimistic that the epidemic can be stopped? Because there is a growing body of evidence that public health approaches such as pairing HIV treatment and prevention and strengthening health care delivery systems in poor countries can help not only slow HIV-AIDS but also make long-needed breakthroughs in reducing the impact of diseases such as malaria and tuberculosis that enslave the developing world.

The good news is hard to find in the new U.N. report, but it's there. While the number of AIDS deaths continues to rise, the rate of increase is slowing, probably because a growing percentage of people in need now have access to HIV treatment. The World Health Organization reports that between 250,000 and 350,000 deaths were averted last year because of expanded access to treatment. More governments are moving to reduce the global HIV death rate by strengthening the health systems that deliver AIDS care. But this effort is proceeding at a maddeningly slow pace that must be stepped up.

Expanding access to treatment is only half the picture, however. The other critical and equally difficult challenge is reducing new HIV infections, which reached 5 million last year. This is no easy task, considering that the United States, with all of its education and technology, has not been able to reduce HIV infection rates in more than 10 years. When you consider that, globally, fewer than one in five people at risk of HIV infection has any access to HIV prevention information, it becomes clear that a new approach is required.

That approach must go beyond AIDS awareness billboards, abstinence education and condom demonstrations. All these have their place, but none has produced the sustained reductions in HIV infections needed to tip this epidemic. The approach that excites public health advocates, and that seems increasingly achievable, is building and strengthening health care systems in the developing world so they can deliver both HIV treatment and prevention, including voluntary counseling and testing.

Before treatment became available in the developing world, governments had little reason to invest in HIV testing, and individuals had no reason to know their status. Today, however, access to treatment is driving new interest in HIV prevention and testing among governments and individuals. In one region of South Africa, demand for voluntary HIV testing and counseling increased by 1,200 percent when treatment became available. The interest and excitement created by the growing availability of HIV care must be marshaled to support the building of health care systems that provide not only HIV services but also education and testing for other diseases that facilitate HIV transmission and exacerbate AIDS, such as malaria, TB and sexually transmitted infections.

Creating basic health care in poor countries is challenging but far from impossible. The World Health Organization and national governments have developed service delivery models that work with reduced numbers of trained health care workers and without expensive equipment or diagnostic tests. There is increasingly compelling evidence that more good can be done with a limited health system than was thought possible.

Governments in some of the world's poorest nations, seeing the potential to improve their health care systems, are becoming more willing to invest the resources and political will needed to manage their HIV epidemics and other health crises. Take Lesotho, a small, southern African nation of 2 million people, where about one in three adults is HIV-positive. Lesotho will soon offer HIV counseling and testing to every citizen, within a framework that protects confidentiality and provides access to care. Nearby Swaziland, where four of 10 adults are infected, provides HIV treatment to more than half its citizens in need, an enormous undertaking that other nations must emulate. The Swazi government aims to deliver quality HIV-AIDS prevention, treatment and care services in 80 percent of health care facilities by the end of 2007.

It would be inaccurate to say that we are close to turning back this epidemic. Current efforts to provide HIV treatment, intensify prevention and strengthen health services are scattered and lack the pace and rhythm needed to make a global impact. If we coordinate efforts, however, to strengthen the health care systems that can holistically address prevention and treatment of HIV-AIDS and the other debilitating diseases of the developing world, there is reason to believe that we can turn a corner on this and other epidemics.

The writer is director of the HIV-AIDS Department at the World Health Organization.