The number of total infections worldwide is now estimated at 33.2 million, down from the 39.5 million estimated last year.
The new estimates cut the number of new HIV infections to 2.5 million a year, a reduction of more than 40 percent from the numbers published last year, according to the Washington Post.
"The single biggest reason for the reduction in global HIV prevalence figures in the past year was the recent revision in India after an intensive reassessment of the epidemic in that country," the UNAIDS report said, according to AFP.
Another reason for the disparity is that previous infection numbers were largely based on rates in pregnant women seeking prenatal care at clinics. Health officials have found this methodology is flawed and skews the numbers towards a higher percentage, reported the New York Times.
The new data reveals that instead of an ever-expanding epidemic, new HIV infections have actually been dropping since peak levels in the late 1990s.
Paul De Lay, UNAIDS director of evidence, monitoring and policy, warned against taking the new data as a sign that the battle against HIV is over.
"If we start to neglect our prevention programs, the epidemic turns around and starts to increase again," De Lay said, according to the AFP.
James Chin, a former World Health Organization AIDS expert said the new revisions don't go far enough. He estimated the number of cases worldwide at 25 million.
"If they're coming out with 33 million, they're getting closer. It's a little high, but it's not outrageous anymore," Chin told the Washington Post.
The United States Agency for International Development has started doing studies based on randomly selected households, and the data is considered a more accurate portrayal of the epidemic.