Your Health History in A Drop of Blood

By Jane Farrell

Thanks to new technology, scientists can use a single drop of human blood to test for current and past viral infections.

The method, called VirScan, was developed by researchers at the Howard Hughes Medical Institute (HHMI), in Chevy Chase, Maryland. It is an efficient alternative to existing tests for specific viruses one at a time. The comprehensive analysis, which would cost about $25 per sample, is now being used only as a research tool.

The technology was reported in the journal Science.

Stephen J. Elledge, an HHMI investigator at Brigham and Women’s Hospital, in Boston, led the development of VirScan. “We’ve developed a screening methodology to basically look back in time [to] see what viruses [patients] have experienced,” he says. “Instead of testing for one individual virus at a time, which is labor intensive, we can assay all of these at once. It’s one-stop shopping.”

VirScan has been used to screen the blood of 569 people in the United States, South Africa, Thailand, and Peru. The technology screens for antibodies against any of the 206 species of viruses known to infect humans and provides a history of a patient’s past infections.

According to a news release from HHMI, Elledge and his colleagues synthesized more than 93,000 short pieces of DNA encoding different segments of viral proteins.

To test the method, the team used it to analyze blood samples from patients known to be infected with particular viruses, including HIV and hepatitis C. “It turns out that it works really well,” Elledge says. “We were in the sensitivity range of 95 to 100 percent for those, and…we  didn’t falsely identify people who were negative. That gave us confidence that we could detect other viruses, and when we did see them we would know they were real.”