NCIt definition : Genus of retroviruses which establish persistent, but non pathogenic infections in
mammals and primates, including humans, chimpanzees, cattle, and cats. It is unique
among retroviruses in having infectious particles that carry DNA rather than RNA.
Similar to hepadnaviruses, spumaviruses bud from the endoplasmic reticulum instead
of the plasma membrane. Infected cells accumulate vacuoles, giving them a foamy appearance
and are often involved in syncytium formation.;