(CNN) -- National Gay Men's HIV/AIDS Awareness Day on Monday will stress what's always been stressed: testing and prevention -- an approach promoted in a study showing 1 in 5 gay men have HIV and nearly half of them are unaware.
But attitudes and awareness about the epidemic, among many young gay men and the rest of America, have shown a shift toward complacency, the U.S. government and groups say.
The share of people who said they had heard, seen, or read "a lot" or "some" about the problem of HIV/AIDS in the United States in the past year declined from 70 percent in 2004 to 45 percent in 2009, according to the Kaiser Family Foundation.
Those naming HIV/AIDS as the most urgent health problem facing the nation "dropped precipitously" between 2006 and 2009, from 17 percent to just 6 percent, the foundation reported. The number had been as high as 44 percent in 1995.
The share of people aged 18-29 who said they were personally very concerned about becoming infected with HIV went from a high of 30 percent in 1997 and 2000 to 17 percent today.
Federal officials talk of the need to "re-energize" and seek "momentum" in the fight against AIDS.
And the latest numbers on HIV may have some wondering whether the epidemic has gone full circle.
HIV is growing in the population largely associated with AIDS when the disease first captured the public's attention in the early to mid-1980s.
"The rate of new HIV infection in the U.S. is increasing among only one risk group: gay, bisexual, and other men who have sex with men," said Jonathan Mermin, director of the Centers for Disease Control and Prevention's Division of HIV/AIDS Prevention.
The CDC report said that low awareness of HIV infection among young gay and bisexual men in 21 major U.S. cities shows the need for better access to HIV testing and prevention programs.
"HIV exacts a devastating toll [on gay men] ... and yet far too many of those who are infected don't know it," said Kevin Fenton, director of the CDC's National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention.
Compounding the problem, the CDC said, is complacency and other factors.
The alarming study, which tested 8,100 subjects, found that young black and Hispanic gay men were more likely to be unaware of their infection. Only 45 percent of HIV-infected gay men who were unaware of their infection had been tested in the past year, the CDC study found.
"For young [gay] men of color, discrimination and socioeconomic factors -- such as poverty, homophobia, stigma, and limited health-care access -- may be especially acute and pose particular challenges," the study found.
Some gay and bisexual men may also believe that advances in HIV treatment minimize the threat, the study's authors said.
Many people with HIV are living longer, most notably former NBA star Earvin "Magic" Johnson, who was diagnosed in 1991.
The White House's HIV/AIDS strategy states "the United States cannot reduce the number of HIV infections nationally without better addressing HIV among gay and bisexual men."
Toward that end, the CDC recently launched a website on gay and bisexual men's health.
Kathleen Sebelius, secretary of the U.S. Department of Health & Human Services, recently told the U.S. Conference on AIDS that America "will regain the momentum we have lost" if government and medical professionals work better together.
Half of Americans believe the government spends too little on the epidemic, the Kaiser Family Foundation survey found.
Getting a firm number on overall federal government spending to fight the HIV/AIDS epidemic is difficult because of how the monies are categorized and grouped. It's estimated to be between $20 billion and $26 billion, with about $3.2 billion going to research. President Barack Obama has proposed $27 billion for 2011.
According to the CDC, there were 35,962 new AIDS cases in 2007, with deaths totaling 11,295, or 3.7 deaths per 100,000 population.
Policy officials talk about the need to shake off complacency.
America "must re-energize" the fight, Fenton said.
"Although it has been nearly 30 years since the first reported cases of HIV among gay and bisexual men, HIV remains a crisis that is far from over in this community," he said.