HIV screening has come a long way since the first tests were released in the 1980s. And yet, many people remain undiagnosed due to stigma.
Human immunodeficiency virus (HIV), or the virus that causes AIDS, debilitates the immune system, preventing the affected person’s body from fighting infection, according to HIV.gov. It is transmitted through bodily fluids, such as blood and semen.
“A significant proportion of individuals with HIV are unaware that they have the virus and continue to spread it as a result,” explained Dr. David Grenache, president of the American Association for Clinical Chemistry. “Many people with HIV also don’t get diagnosed until they’ve been infected for several years, by which point it’s often too late to prevent complications from the virus with treatment. Clinical laboratory testing for HIV is essential to diagnosing these unknown cases early so that these patients can start treatment in a timely manner, and to curtail the spread of the disease.”
Tests are getting better
Today, there are three tests available to diagnose HIV: a test for combined HIV antigens or antibodies; a test to differentiate between HIV-1 and HIV-2, the two major types of HIV; and, a test to determine the genetic material of the virus. When and how these tests are used depend on a person’s individual health, according to Centers for Disease Control and Prevention guidelines issued in 2014.
Now, besides being more detailed, the turnaround time for HIV results is quicker. “When HIV first emerged, tests could not detect the virus until months after the patient’s initial exposure,” Grenache said. “Since then, clinical laboratory experts have developed new tests that reduce this detection window considerably and speed up the time it takes for patients to get their results.”
In 2010, the fourth-generation HIV tests used today were released. Now, they can tell whether a person was exposed two to four weeks after the suspected time of infection. A fifth-generation test with even faster results may be on the horizon, Grenache said.
Meanwhile, healthcare is advancing more rapid point-of-care HIV testing, or testing done outside of a lab. “These tests could be widely deployed in the resource-limited areas hardest hit by the HIV epidemic,” Grenache explained.
Despite these improvements in accurately and quickly diagnosing HIV, stigma prevents many patients from seeking, accepting, or following through with screening, he added. “The rapid point-of-care genetic tests that are in development could solve this problem by confirming HIV screening results while patients are still on site,” Grenache explained. “In turn, this would enable providers to start treating patients immediately.”
There are still challenges, including potential production of false-negative or conflicting HIV test results in individuals who have taken but not adhered to pre-exposure prophylaxis (or PrEP) medication. PrEP is used to prevent HIV infection in at-risk individuals. “However,” Grenache added, “this is the best kind of problem we face. Issues like this are a result of improved patient care and progress toward ending the HIV epidemic, and the work needed to resolve them is more than worth it.”