"This complacency cuts across all the main sectors of society and will be one of the main challenges we will have moving forward," said Kevin Fenton, director of the US Centers for Disease Control and Prevention (CDC).
The CDC, which last week increased its estimate of annual HIV infections in the United States by 40 percent to 56,300, called Wednesday for action in response to its new figures.
"These data are a wake up call to all of us," Fenton said, underlining that the organization itself supported activists' calls for a national US HIV plan.
The AIDS activists welcomed his comments, but called for more action to address the social problems behind the figures, which showed that gay and bisexual men, as well as and African American men and women, are the groups most affected by HIV.
"HIV is not just a disease, it's proof of social injustice," read some banners carried by demonstrators calling for better access to housing and healthcare for HIV-positive minorities.
"At what point are we going to stop making a footnote of the things that are driving these problems?" asked Kenyon Farrow from the Queers for Economic Justice organization in New York.
Meanwhile, after President George W. Bush last month signed legislation tripling funds to fight AIDS, malaria and tuberculosis in the world's poorest countries, many called for a similar plan at home.
African Americans, who make up 13 percent of the US population, accounted for 45 percent of the new infections in 2006, according to the latest figures.
"If black America was a separate nation, it would rank 16 in world HIV rankings," said congresswoman Barbara Lee. "I think it's about time we call for a national AIDS strategy and national AIDS plan."
But many of the 22,000 scientists, policymakers and field workers here wondered just how to rally the public to back such new initiatives in the era of antiretroviral drugs, which have transformed HIV infection from a death sentence to a chronic but manageable condition.
"The great fear I have is that AIDS itself will lose its power and interest," Seth Berkley, president and CEO of the New York-based International AIDS Vaccine Initiative (IAVI), told AFP.
"Partly this is because so many resources have been pumped in, people kind of feel, we've taken care of it, and as we know, we haven't."
He noted that, although the US figures had been underestimated, they had remained stable for 10 to 15 years, which suggested that AIDS prevention campaigns had run into a wall of complacency.
More than 25 million people have died from AIDS since the disease first emerged in 1981, and 33 million people today are living with HIV, two-thirds of them in sub-Saharan Africa.