- Category: HIV Testing & Diagnosis
- Published on Tuesday, 20 November 2012 00:00
- Written by Liz Highleyman
Adolescents and adults between the ages of 15 and 65 years should be routinely screened for HIV, and people outside this age range should also be tested if they are at risk of infection, according to draft recommendations from the U.S. Preventive Services Task Force (USPSTF) issued this week. The Task Force also advised that all pregnant women should be screened for the virus.
The U.S. Centers for Disease Control and Prevention (CDC) estimates that 1 in 5 people with HIV are unaware they are infected. Learning one's HIV status is the first step toward accessing timely care and treatment. Further, studies suggest that a large proportion of new infections are transmitted by people who do not know they are positive, so wider testing could also promote prevention.
The USPSTF is an independent group of national experts in prevention and evidence-based medicine that makes evidence-based recommendations about clinical preventive services such as screenings, counseling services, and preventive medication.
Summary of USPSTF Recommendations
- The Task Force strongly recommends that clinicians screen all people aged 15 to 65 for HIV infection.
- Younger adolescents and older adults who are at an increased risk for HIV infection should also be screened.
- The Task Force also strongly recommends that clinicians screen all pregnant women for HIV, including women in labor whose HIV status is unknown.
The Task Force recommendations mirror those issued by the CDC in 2006, advising that all adults and adolescents should be tested for HIV at least once, and people with ongoing risk should be tested at least annually.
"The draft recommendation reflects new evidence that demonstrates the benefits of both screening for and earlier treatment of HIV," Task Force member Douglas Owens, MD, stated in a USPSTF Bulletin issued November 20. "People who are feeling well and learn they are infected with HIV can begin treatment earlier, reduce their chances of developing AIDS and live longer and healthier lives."
"The task force’s draft recommendation, if fully adopted, is potentially game changing in helping to identify the nearly 20 percent of individuals infected with HIV in this country who do not know they are infected and connecting them with lifesaving HIV care and treatment," said HIV Medicine Association (HIVMA) Chair Michael Horberg, MD, in a statement issued by the organization.
"We know that early and successful management of HIV infection results in better health outcomes for those who are infected and greatly reduces their risk of transmitting the virus to others," he continued. "Yet as many as one-third of patients with HIV infection today are diagnosed too late to fully benefit from treatment and less than 40 percent of people with HIV are in regular care."
According to Horberg, the Task Force recommendations would make routine HIV screening a covered preventive service offered for free under the Patient Protection and Affordable Care Act.
The Task Force is accepting public comment on the draft until December 17, 2012. The recommendations are available online at http://www.uspreventiveservicestaskforce.org and comments can be submitted at www.uspreventiveservicestaskforce.org/tfcomment.htm.
Review of Evidence
The recommendation is based on part on a review of recent research about HIV testing and its outcomes. Results from 2 literature reviews -- one regarding adults and adolescents, the other focusing on pregnant women -- were published in the November 20, 2012, Annals of Internal Medicine.
Roger Chou from the Oregon Evidence-based Practice Center and Oregon Health and Science University and colleagues searched MEDLINE and the Cochrane Library to identify relevant research released since the 2005 USPSTF HIV screening review.
The earlier review "found good evidence that HIV screening is accurate and that antiretroviral therapy (ART) for immunologically advanced disease is associated with substantial clinical benefits, but insufficient evidence to determine the effects on transmission or in less immunologically advanced disease," the authors noted as background.
In addition to evaluating data from randomized trials and observational studies that compared HIV screening strategies and outcomes, the review authors also looked at studies on the benefits and drawbacks of starting ART at different CD4 T-cell thresholds, as well as the effects of interventions on HIV transmission risk.
In summary, they found recent evidence clearly indicating that it is beneficial to start ART before a person's CD4 count falls below 350 cells/mm3, as well as large cohort studies consistently showing that ART initiation at CD4 counts between 350 and 500 cells/mm3 is associated with lower risk of death or progression to AIDS. The latest U.S. federal HIV treatment guidelines, issued this past March, recommend that ART should be offered to everyone diagnosed with HIV regardless of CD4 cell level.
Turning to prevention, the authors wrote, "Strong evidence from 1 good-quality randomized trial and 7 observational studies found that ART was associated with a 10- to 20-fold reduction in risk for sexual transmission of HIV."
"Previous studies have shown that HIV screening is accurate, targeted screening misses a substantial proportion of cases, and treatments are effective in patients with advanced immunodeficiency," they concluded. "New evidence indicates that ART reduces risk for AIDS-defining events and death in persons with less advanced immunodeficiency and reduces sexual transmission of HIV."
In the second review, they found evidence from U.S. studies confirming that full-course combination ART substantially reduces the risk of mother-to-child HIV transmission. However, they added, evidence about long-term maternal harm after short-term ART exposure during pregnancy -- that is, time-limited administration of fewer antiretroviral drugs to prevent mother-to-child transmission, as commonly done in resource-limited settings -- remains "sparse."
"Antiretroviral therapy in combination with avoidance of breastfeeding and elective cesarean section in women with viremia reduces risk for mother-to-child transmission," the authors concluded. "Use of certain antiretroviral therapy regimens during pregnancy may increase risk for preterm delivery."
R Chou, S Selph, T Dana, et al. Screening for HIV: Systematic Review to Update the 2005 U.S. Preventive Services Task Force Recommendation. Annals of Internal Medicine 157(10):706-718. November 20, 2012.
R Chou, AG Cantor, B Zakher, et al. Screening for HIV in Pregnant Women: Systematic Review to Update the 2005 U.S. Preventive Services Task Force Recommendation. Annals of Internal Medicine 157(10):719-728. November 20, 2012.
U.S. Preventive Services Task Force. U.S. Preventive Services Task Force Issues Draft Recommendation on Screening for Human Immunodeficiency Virus (HIV). USPSTF Bulletin. November 20, 2012.
Michael Horberg, HIV Medicine Association. HIV Experts Applaud Recommendation for Routine HIV Screening. Media statement. November 19, 2012.