Freeman Spogli Institute for International Studies Center for Health Policy/Center for Primary Care and Outcomes Research Stanford University


A nurse arranges test tubes containing blood taken during a free HIV test. A government-backed panel says all adults in the U.S. should be tested for HIV at least once.
Photo credit: Reuters



November 19, 2012 - FSI Stanford, CHP/PCOR News

Screening all adults would slow spread of AIDS

By Ruthann Richter

A government-backed panel of medical experts says everyone between the ages of 15 and 65 in the United States should be tested at least once in their lives for HIV, a policy that Stanford’s Douglas K. Owens says could have a substantial impact on the course of the epidemic.

Owens, a professor of medicine and director of Stanford Health Policy at the university’s Freeman Spogli Institute for International Studies, is a member of the U.S. Preventive Services Task Force, which issued its draft recommendation on Nov. 19.

Currently, there are an estimated 1.2 million people in the nation infected with HIV, and some 20 to 25 percent of them aren’t aware they carry the virus that causes AIDS. If they were diagnosed, they could get into treatment programs, which would benefit them as well as helping to prevent the spread of the disease.

“We think it’s important for everyone to be screened once because treatment helps people live longer, healthier lives and also prevents transmission to others,” said Owens, who is also a senior investigator at the Veterans Affairs Palo Alto Health Care System.

Those at very high risk, including gay men and injection drug users, should be tested every year, while others considered at increased risk also should undergo repeat testing with the frequency depending on risk, the task force recommends. In addition, the panel said practitioners should screen all pregnant women for the virus; the practice, now common in this country, has helped virtually eliminate the incidence of mother-to-child transmission, Owens noted.

In 2005, the task force strongly recommended HIV screening in adolescents and adults considered at increased risk for HIV, but it stopped short of recommending a universal testing program.  The new recommendation for widespread screening reflects the changing world of AIDS science, Owens said.

For instance, studies have shown that an early diagnosis — even before symptoms begin to emerge — followed by effective antiretroviral treatment, can help prevent individuals from developing life-threatening complications. Moreover, HIV-infected individuals who are treated with antiretroviral drugs are much less likely to pass on the virus to others. A landmark study published in August 2011 and involving 1,763 heterosexual couples (in which one was HIV-positive and the other was not) found that treating the infected partner reduced his or her chance of transmitting the virus by 96 percent.

In addition, once people are diagnosed, they can be counseled about changing their behaviors to help prevent the spread of the disease. Observational studies have shown that people who know their HIV status are more likely to take precautions, for instance, by using condoms, avoiding sex with sex workers or having sex in exchange for money or drugs, the task force noted.

In 2006, the federal Centers for Disease Control recommended routine voluntary screening for everyone aged 13 to 64, but allowed them to opt out of testing. Many other professional groups, such as the American College of Physicians, also advise routine patient screening. Yet universal screening, followed by treatment, has never been achieved in this country.

Owens said the task force did consider the potential harms of screening and testing. One potential drawback is a false-positive test result, though the screening test is highly accurate, so this risk is quite small, he said. Treatment also may carry side effects, including the possibility of a slightly increased risk for heart problems. Stigmatization and labeling are other potential downsides of testing, he said.

But on balance, he said, “We feel the benefits are so substantial that they far outweigh the potential harm.”

He said the task force also emphasized the importance of prevention: “The best way to reduce HIV disease and death is to avoid becoming infected. So we want people to take actions to reduce their risk behaviors, such as using safe sex practices and avoiding other behaviors that put them at risk.”

The task force’s draft recommendation has been posted for public comment on its website at http://www.uspreventiveservicestaskforce.org. Comments can be submitted from Nov. 20 to Dec. 17 at www.uspreventiveservicestaskforce.org/tfcomment.htm. The panel then will finalize its recommendations, which will be published in the Annals of Internal Medicine.

Ruthann Richter is the director of media relations at the Stanford School of Medicine.