WASHINGTON (Reuters) - The number of people killed by AIDS worldwide edged down for a second straight year in 2007 after rising for more than two decades amid intensified global efforts to fight the disease, a U.N. agency said Tuesday.

About 33 million people were living with human immunodeficiency virus infections in 2007, most of them in Africa, south of the Sahara Desert, according to the United Nations report on the AIDS epidemic.

Global deaths from AIDS reached an estimated 2 million in 2007, down from 2.1 million deaths in 2006, the Geneva-based UNAIDS agency said. Global AIDS deaths peaked in 2005 at 2.2 million after a steady climb since the disease was first identified in the early 1980s, UNAIDS said.

The total number of people living with HIV infections continues to inch higher as more and more people in hard-hit regions like sub-Saharan Africa get access to drugs that help them live longer, the report showed.

The number of people who became newly infected with HIV, which ravages the immune system, was basically the same in 2007 as in 2006 -- at around 2.7 million people, with a very small increase last year over the prior year, the agency said.

The number of newly infected people peaked at 3.5 million in 1996 and has been on a downward trend since, UNAIDS said.

"There are still five new infections for every two people who are newly added on treatment. So clearly, we're not pushing back the epidemic enough," UNAIDS official Dr. Paul De Lay said.

"While the number of new HIV infections has fallen in many regions and in many countries, the AIDS epidemic is not over in any part of the world."

About 7,500 people a day become infected with HIV, spread most often through sexual contact and injection drug use, according to the report.

Two-thirds of people infected with HIV live in sub-Saharan Africa and 60 percent of them are women, UNAIDS said.

The report said rates of new infections are rising in many countries including China, Indonesia, Kenya, Mozambique, Papua New Guinea, Russia, Ukraine and Vietnam. Infections also are increasing in countries like Germany, Britain and Australia.

"A six-fold increase in financing for HIV programs in low- and middle-income countries (from) 2001-2007 is beginning to bear fruit, as gains in lowering the number of AIDS deaths and preventing new infections are apparent in many countries," according to the report.

"Progress remains uneven, however, and the epidemic's future is still uncertain, underscoring the need for intensified action to move towards universal access to HIV prevention, treatment, care and support," said the report, launched ahead of an international AIDS conference in Mexico next week.

UNAIDS said its report used data from 147 countries, but De Lay said he was disappointed that the United States did not provide its 2007 AIDS figures because U.S. officials continue to "refine" the numbers and will announce them soon.

The report was released five days after the U.S. Congress approved a large expansion of a program to fight AIDS and other diseases in Africa and other parts of the world, sending it to President Bush to sign it into law.

The measure calls for $48 billion over the next five years to help treat and prevent AIDS, tuberculosis and malaria. That is up sharply from the $15 billion Congress initially funded for the first five years of the program that began in 2003.

The report said about 3 million people are receiving AIDS drugs in low- and middle-income countries. In most places, it said, more women are receiving treatment than men.

The report also comes amid several setbacks in efforts to develop an effective vaccine against AIDS.

Key points on South Africa from UNAIDS 2008 Report on the global AIDS epidemic:

• "HIV data from antenatal clinics in South Africa suggest that the country's epidemic might be stabilising, but there is no evidence yet of major changes in HIV-related behaviour. The estimated 5.7 million [4.9 million-6.6 million] South Africans living with HIV in 2007 make this the largest HIV epidemic in the world."
• "According to a national survey of more than 7000 people (ages 15-65) in South Africa, pervasive social norms encourage both concurrency and a rapid turnover in sex partners, with little peer support for commitment to a single partner. Significantly, only 21% of survey respondents said "sticking to one partner and being faithful" could prevent HIV transmission, and only 5% identified reducing the number of sex partners as a sound HIV prevention strategy."
• "The growing availability of antiretroviral drugs is lessening the burden of HIV-related mortality in low- and middle-income countries, as it did in high-income countries a decade ago. In rural South Africa, substantial declines in mortality were reported in 2006, as these drugs became increasingly available. After decades of increasing mortality, the annual number of AIDS deaths globally has declined in the past two years, in part as a result of the substantial increase in HIV treatment access in recent years."