(WASHINGTON) -- In an effort to curb HIV transmission and get treatment to those already infected, the U.S. Preventive Services Task Force has recommended that every American between the ages of 15 and 65 be tested for HIV.
Experts hope that the new recommendations will encourage more Americans to get tested and, if necessary, get treated.
"HIV screening is an important way to help people who have HIV, and also to prevent transmission," said Dr. Doug Owens, a leader of the task force and professor of medicine at Stanford University and the Veterans Affairs Palo Alto Health Care System.
Owens said that HIV treatment "decreases the amount of circulating virus," making it less likely for it to spread from person to person.
Roughly 1.2 million Americans are currently living with HIV -- a number that has been increasing steadily over the past five years, according to the U.S. Centers for Disease Control and Prevention. There continue to be about 48,000 new cases per year in the United States, but new treatments are allowing people to live long lives after they're diagnosed.
"Hopefully, more people with HIV will be identified and treated earlier," said Dr. Roger Chou of the Pacific Northwest Evidence Based Practice Center, whose study on the evidence supporting the new recommendation was published Tuesday in the Annals of Internal Medicine.
HIV-positive patients who start treatment while their immune systems are relatively intact live longer and are less likely to spread the virus to other people. But 20 percent of patients are unaware they have the virus, said Dr. Carlos Del Rio, co-director of the Emory Center for AIDS research in Atlanta.
"This news about screening is very exciting," Del Rio said.
Previous task force recommendations on HIV testing, published in 2005, called for adults to get tested only if they'd had unprotected sex with multiple partners or used intravenous drugs -- in other words, were at high risk. But up to a quarter of patients who test positive for HIV report no risk factors, according to the new Preventive Services Task Force statement.
"People are terrible at knowing their own risk," said Del Rio, adding that people may be unaware of the HIV status of their sexual partners. "And doctors are terrible at asking them about risk. It can be difficult to discuss sex and drugs with our patients."
The task force recommendations are used by Medicare and other insurance companies to determine what laboratory tests should be covered. Other important task force recommendations included screening for breast and colon cancer, as well as high cholesterol.
"I don't have to ask my patients if they eat hamburgers before ordering a cholesterol test," said Del Rio. "Now I can do a routine HIV test when patients come to clinic."
In order for the U.S. Preventive Services Task Force to make a testing recommendation, the test has to be accurate, treatment for the disease must be available and the benefits of the treatment outweigh the harms.
"HIV testing is one of the most accurate tests that we have for any condition," said Chou.
Coupled with the fact that the benefits of HIV treatment are now known to outweigh the risks, screening now makes sense, according to the experts on the task force.
Copyright 2012 ABC News Radio