New Blood TestViral infections not only cause acute or chronic illness directly, but can also alter host immunity, leaving a permanent footprint on the immune system.

Current assays screen for only one virus at a time. Now, researchers from Harvard University and other research centers in the U.S., Europe, Peru, Thailand and South Africa have developed a DNA-based blood test that can identify all the viruses that people have ever had in their life time.

This affordable test which costs just $25 uses only a single drop of blood and is expected to help researchers better understand the interaction between the human immune system and these viruses. VirScan could transform the detection of serious viral infections such as hepatitis C and HIV, which many people don’t even know they are carrying. The test detects antibodies that the body has used to fight previous viral infections. Past exposure to more than 1,000 strains of viruses from 206 species can be identified.

Blood samples were taken from 569 participants from four countries on four different continents. It is reported that VirScan’s performance in detecting known infections is comparable to that of traditional serum antibody tests for single viruses. On average, the test revealed ten viral species per donor, though some people showed exposure to more than double that number. Up to 84 species were identified in at least two individuals.

According to the researchers, “VirScan may prove to be an important tool for uncovering the effect of host-virome interactions on human health and disease and could easily be expanded to include new viruses as they are discovered, as well as other human pathogens, such as bacteria, fungi, and protozoa.” In the early stages of testing, this blood test requires FDA approval to be used in laboratories.