EXAMPLES OF CYTOPATHIC EFFECT (CPE)

CELL SWELLING & GRAPELIKE CLUSTERING

Cells become swollen, rounded, and enlarged, aggregating together into distinctive grapelike clusters.

Adenovirus

Associated Virus in Cell Swelling & Grapelike Clustering

SYNCYTIUM FORMATION (MULTINUCLEATED GIANT CELLS)

Fusion of adjacent cell membranes forming large, multinucleated giant cells

Respiratory Syncytial Virus (RSV), Parainfluenza Viruses (PIV), Measles Virus

Associated virus of Synctium Formation

SHRINKAGE, CRENATION & PYKNOSIS

Rapid, widespread shrunken, refractile, crenated cells with pyknotic nuclei.

Enteroviruses (Poliovirus, Coxsackie, Echovirus)

Associated virus of Shrinkage, crenation & pyknosis

TEAR-DROP ROUNDING

Small, rounded, refractile, tear-drop-shaped cells that detach from the surface

Rhinovirus

Associated virus of Tear-droping Rounding

OWL'S EYE INCLUSIONS & CYTOMEGALY

Focal enlarged, swollen cells with central intranuclear inclusions and clear halos

Cytomegalovirus (CMV)

Associated Virus of Owl’s Eye Inclusions

HEMADSORPTION

Used to detect viruses that express hemagglutinin proteins (e.g., influenza, parainfluenza, mumps, measles) on the surface of infected host cells. It involves adding red blood cells (RBCs) to cultured cells, which then adhere to the viral proteins, allowing early detection (often in 24-48 hours) of infection before cytopathic effects (CPE) are visible

VIRAL PLAQUE / PLAQUE FORMATION

The localized destruction of a confluent cell monolayer by viral infection, appearing as clear, circular spots (plaques) after staining

Negative

Uninfected monolayer

Equivocal (±)

1% to 25% of monolayer involving few cells

1+

1% to 25% of monolayer exhibits cytopathic effect (CPE)

2+

25% to 50% of monolayer exhibits CPE

3+

50% to 75% of monolayer exhibits CPE

4+

76% to 100% of monolayer exhibits CPE