Expanding screening for HIV in the United States and implementing broader use of treatment could reduce the number of new infections while still being cost effective, according to a new study.

Each year about 56,000 people in the U.S. are infected with HIV, the virus that causes AIDS, and that number has remained fairly steady for at least the last five years, the researchers said. It's estimated that  21 percent of people with HIV are not aware they carry the virus, and may spread the it unknowingly, according to the Centers for Disease Control and Prevention.

While the CDC recommends routine HIV screening for people ages 13 to 64, universal testing for the virus in this country is not done. And access and adherence to treatment still remains an issue.

If nothing is done to augment either HIV screening or treatment over the next two decades, about 1.23 million people in the U.S. will be infected with HIV, the researchers said.

The new study shows a program that screens high-risk individuals once a year, and everyone else, between the ages of 15 to 64, once during their lifetime, could prevent nearly 82,000 infections over the next 20 years. People at high risk for contracting HIV include men who have sex with men and injection drug users.

Scaling up HIV treatment so that it reaches 75 percent of people who are infected with HIV and meet the requirements for taking HIV antiretroviral drugs (meaning their white blood cell count falls within a certain range) could prevent more than 125,000 infections, the study showed.

Combined, these two interventions could prevent around 212,000 infections over two decades, or 17.3 percent of projected infections.
Screening and treatment programs act together, synergistically so that the combined effect is bigger than the impact of either one alone, the researchers said.

"Efforts that are focusing only on screening, or conversely, focusing only on treatment, miss some of the potential benefit," of scaling both these treatments up together, said study researcher Elisa Long, an assistant professor of operations management at Yale University.

Such a screening effort would cost about $92.6 billion over 20 years. The sum includes the money needed for screening and treatment, as well as the costs that come with people with HIV living longer, such as additional health expenses for other conditions, said Dr. Douglas Owens, a researcher at the Veterans Affairs Palo Alto Health Care System in Palo Alto, Calif.

Together, the treatment and screening interventions would cost less than $23,000 for every "quality-adjusted life year" gained — an amount on par with other disease prevention strategies, such as breast cancer mammograms and screening for Type 2 diabetes, the study found. Quality-adjusted life years are the number of years a particular intervention extends life, taking into account a person's state of health. Interventions that cost less than $50,000 per quality-adjusted life year are considered good value for health-care dollars, Owens said.

The study is one of the first to look at the impact of increasing both screening and treatment on a national model of HIV transmission in the United States.

The model assumes people who test positive for HIV will modestly reduce their risky behavior, including reducing their number of sexual partners or decreasing needle sharing, the researchers said. Previous studies have shown such reductions among people who received counseling.

Improvements in screening and treatment won't be enough to eliminate HIV from the country, the researchers said. But if additional measures are taken to reduce risky behaviors — specifically, if men who have sex with men reduced their number of sexual partners by one-half, and drug users reduced the number of needles they shared by one half — then 65 percent of HIV infections could be prevented.

"We can't screen and treat our way out of the epidemic in the U.S.," Long said. "We also need to scale up prevention efforts," she said.

The results will be published tomorrow (Dec. 21) in the journal Annals of Internal Medicine.

Pass it on: Screening everyone for HIV once in their lifetime, and screening high-risk people yearly, along with treatment improvements, could prevent 212,000 HIV infections over the next 20 years.

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