The number of HIV cases among young gay men has increased in a big way, the Centers for Disease Control (CDC) reported Thursday. The CDC stated that from 2001 to 2006, the largest transmission category for HIV in the U.S. was in men who had sex with men.

Gay boys and men aged between 13 and 24-years old saw the biggest increase in HIV cases, about 10 times higher than in the homosexual community overall, where the number of new infections is going up about 1.5 percent a year. homosexual men were the only risk group in which the number of new infections rose annually from 2001 through 2006.

The new data cover over 200,000 cases in 33 states including New York, Florida, New Jersey and Texas, all of which have large numbers of HIV-infected people. The CDC is stressing that testing is important, as it can lead to lesser transmission if they know they are HIV positive.

Among African-American men of all ages who have sex with men, the annual increase in diagnoses was 1.9 percent. The CDC released their findings in their weekly journal, the Morbidity and Mortality Weekly Report.