Americans with HIV are getting diagnosed faster than ever before, but most people who are infected carry the virus for years before they know it. On average, people infected with the AIDS virus go three years before they are tested and told about it, the Centers for Disease Control and Prevention reported Tuesday. That’s three years during which the virus is eroding away at their immune systems, leaving them vulnerable to other infections — and three years during which they can infect others without even knowing it. But it’s still an improvement, the CDC team said. In 2011, people went an average of three years and seven months before they got a test and diagnosis. Paul Cheung / CDC “These findings are more encouraging signs that the tide continues to turn on our nation’s HIV epidemic,” said CDC Director Dr. Brenda Fitzgerald. “HIV is being diagnosed more quickly, the number of people who have the virus under control is up, and annual infections are down.” But three years is still too long and this gap between infection and detection is helping keep the virus in circulation, the CDC said. “Ideally, HIV is diagnosed within months of infection, rather than years later,” said Dr. Eugene McCray, director of CDC’s Division of HIV/AIDS Prevention. About 1.1 million Americans are infected with the human immunodeficiency virus (HIV) that causes AIDS. Thanks to better testing, about 85 percent of them know it, and nearly half, 49 percent, have the virus under control with drugs. “40 percent of HIV infections in the United States are inadvertently, unknowingly being transmitted by persons who don’t know they have HIV.” There’s no cure for HIV and no vaccine on the market yet, but increasingly simplified drug cocktails – some as simple as a single daily pill — can control the virus so that it cannot be easily detected in the blood, doesn’t make people sick and makes it almost impossible to transmit to others. Some groups go even longer than three years. For heterosexual men, it takes on average five years to get tested and diagnosed, in part because straight men don’t think they are at high risk. “Fifty percent of persons with HIV infection diagnosed in 2015 had been