(CNN) -- The number of people around the world living with the virus that causes AIDS is actually nearly seven million fewer than previous estimates, according to the United Nations.
But while the lower numbers are encouraging, there is still work to be done in the areas of prevention and treatment, especially in sub-Saharan Africa, where 68 percent of those infected with HIV live, the report released by the Joint United Nations Program on HIV/AIDS (UNAIDS) and the World Health Organization (WHO) showed.
Better information from more countries prompted the groups to revise the 2006 estimate of 39.5 million people living with HIV to 32.7 million, according to a statement from UNAIDS.
The single biggest factor in the reduction, the report said, was the "recent revision of estimates in India after an intensive reassessment of the epidemic in that country." Watch more on the changing AIDS numbers »
Other factors include the revision of estimates in Angola, Kenya, Mozambique, Nigeria and Zimbabwe, the statement said.
"The data for measuring the HIV epidemic used by UNAIDS/WHO has considerably expanded and improved in recent years," said Ron Brookmeyer, Professor of Biostatistics and Chair of the Master of Public Health Program, The Johns Hopkins Bloomberg School of Public Health.
"Nevertheless, there is a need to further improve the representativeness of the underlying data. There is a need to expand disease surveillance systems to better track the sub-epidemics in risk populations within each county."
Current figures show 33.2 million people living with HIV in 2007 -- with 22.5 million of them in sub-Saharan Africa, according to 2007 statistics from the report.
That region also accounts for 1.7 million new HIV infections for 2007 -- of a global total of 2.5 million new infections -- and eight countries in that area account for nearly one third of the 2.1 million AIDS deaths, the report said.
"AIDS is among the leading causes of death globally and remains the primary cause of death in Africa," the statement on the report said.
"In sub-Saharan Africa, continued treatment scale-up and HIV prevention efforts are also bringing results in some countries, but mortality from AIDS remains high in Africa due to the extensive unmet treatment need."
However, it noted, "the number of people dying from AIDS-related illnesses (globally) has declined in the last two years, due in part to the life prolonging effects of antiretroviral therapy."
The number of new HIV infections is leveling off, the groups said, but there are still 6,800 new infections and 5,700 AIDS-related deaths each day.
With the revised data, the report showed, the number of new HIV infections per year peaked in the late 1990s at more than 3 million.
Other key findings in the report: