[1] It was discovered and reported in 2013 after isolation from the organs of the gastrointestinal tract, particularly the liver.

[3] HPyV12 was first discovered in 2013 by generic PCR used to screen samples of the organs of the gastrointestinal tract.

HPyV12 was identified first and most commonly in liver samples; it was also occasionally detected in the colon and rectum and in feces.

[2] The HPyV12 genome follows the typical organization for a polyomavirus, containing a small and large tumor antigen and three viral capsid proteins; it has no open reading frame corresponding to an agnoprotein.

A 2013 survey found that between 15–33% of healthy adults exhibited evidence of exposure, with slightly lower rates in children.