Genital herpes tests are notoriously unreliable, but better ones are in the works

Genital herpes tests are notoriously unreliable, but better ones are in the works

The best blood test for herpes is only available at a single lab. What would it take for that to change?

Last fall Alexa started seeing a man she met on a dating app. He asked her to get tested for sexually transmitted infections before they began having sex. The first thing she noticed on her screening panel was the word “HIGH” in red text: the test had detected elevated antibodies against HSV-2, the form of herpes simplex virus that causes most genital herpes.

This result prompted the lab to run a confirmation test, which determined that Alexa (who asked to be identified with a pseudonym) did not have the virus. She received both results at the same time, but the initial label on the panel was enough to scare off her prospective partner. The false positive “ruined a connection because of how bad the stigma is,” Alexa says.

This prejudice persists despite the high prevalence of herpes. An estimated 12 percent of people in the U.S. aged 14 to 49 have genital herpes caused by HSV-2, but most are unaware of their condition, according to the Centers for Disease Control and Prevention. While there is no cure for herpes and the condition can recur throughout a person’s life, many people have few or no symptoms.

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In the absence of active lesions to swab for HSV itself, tests must evaluate the immune response to the virus in a patient’s blood, typically by screening for the immunoglobulin G (IgG) antibody. But the tests are prone to false positives , and the U.S. Preventive Services Task Force, an independent body that sets evidence-based clinical practice standards, recommends against screening asymptomatic individuals.

More accurate automated herpes blood tests have emerged in recent years, but not all commercial labs have adopted them, says Jeffrey Klausner , a clinical professor at the University of Southern California Keck School of Medicine and president of the nonprofit Herpes Cure Advocacy , which was founded in 2020 to promote research into diagnostics and treatments. The “gold standard” test for herpes infection, a type of assay called a Western blot, requires a human to read it and is performed solely at the University of Washington (UW) Virology Laboratory; it’s not widely available to consumers. But researchers are hoping to change that.