More than half of young people in the United States who are infected with HIV are not aware of it, according to a new government report that zeroes in on one of the remaining hot spots of HIV infection in America.

Young people ages 13 to 24 account for 26 percent of all new HIV infections, according to the U.S. Centers for Disease Control and Prevention, which released the report on Tuesday.

"Given everything we know about HIV and how to prevent it in 30 years of fighting the disease, it's just unacceptable that young people are becoming infected at such high rates," CDC Director Dr. Thomas Frieden said.

Every month, 1,000 young people in America become infected with HIV, an incurable infection that costs $400,000 to treat over a lifetime, Frieden said. If left untreated, HIV infection leads to AIDS and early death.

"The data are stark and worrying," said Dr. Kevin Fenton, director of the National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention at the CDC.

In 2010, 72 percent of the estimated 12,000 new HIV infections in young people occurred in young men who have sex with men, and nearly half of new infections were among young, black males.

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