More than a quarter of new HIV infections in the United States strike young people aged 13 to 24 and 60 percent of those don't know they're sick, health officials said Tuesday.
An estimated 12,200 youth were infected with HIV in 2010, the Centers for Disease Control and Prevention (CDC) said in a new study.
Young gay and bisexual men and African American youths were hit hardest, and the study found a variety of reasons for risky behavior that increases the risk of contracting the virus.
Only 13 percent of high school students and 35 percent of 18 to 24-year-olds have been checked for HIV despite recommendations for routine testing.
The failure to test has contributed to the fact that young people are far less likely to get and stay in treatment programs that can keep the virus in check, help them stay healthy and reduce the risk of further transmission, according to the CDC.
"That so many young people become infected with HIV each year is a preventable tragedy," CDC Director Thomas Frieden said in a statement.
"All young people can protect their health, avoid contracting and transmitting the virus, and learn their HIV status."
The CDC estimates that about 50,000 people are infected with HIV each year in the United States and that youth make up seven percent of the 1.1 million Americans living with HIV.
Nearly 60 percent of new infections among youth occur in American Americans, while 20 percent are among Hispanic youth and 20 percent among white youth. African Americans make up just 12.6 percent of the overall population.
Young men were also disproportionately affected, representing 83 percent of those infected.
This was primarily because of sharply higher rates among gay and bisexual males who were less likely to use condoms, and more likely to have multiple partners and drink alcohol or do drugs prior to having sex.