Both in cell cultures and in infected tissues, viral infection can lead to the development of foamy vacuolated cells, which may form syncytia (fused cells). The cellular changes can be readily seen using electron microscopy. With most conventional viruses, the formation of intact viral particles precedes the induction of major cytopathic effects. The appearance of intact fully formed viral particles is much less of a feature in stealth virus infected cells. More commonly one can see accumulations of varying types of granular components, occasionally with incomplete virus-like structures, in cells displaying intense cytopathic effects, including mitochondria disruption, lipid-filled vacuoles and deranged nuclei.

The types of viral-like products that accumulate in stealth viral infected cells differ between various stealth viral isolates. In some cultures the predominant material may be coarse nucleocapsid-like materials, in others there may be collections of fine granular deposits, still other cultures may show an over expression of viral envelope-like structures. A common feature, however, is the apparent metabolic disruption outpacing both the production of complete virus particles. The vacuolating cytopathic effect is also different from the "cell death response", known as apoptosis, that is triggered by several types of conventional virus infections.