With just a single drop of blood it is possible to know the entire list of viruses that infected a person up until the moment of testing.
The virus SIRV2 may have helped solve one of the biggest hurdles in gene therapy; transporting DNA into body to treat disease without the immune system destroying.
The test will have to undergo more work before it can be clinically deployed.
The genome sequencing project has shown about 20 million genetic changes in Icelandic people.
