Dr  Sampurna Roy  MD

The causative viruses are large with a DNA core and a surrounding capsid.

Poxvirus infection occur in human and animals.

These are members of Poxviridae family.

There are two subgroups, based on the morphological features of the virus.

The viruses of molluscum contagiosum and orf are oval or cylindrical in shape and measure approximately 150x300 nm.

The remaining viruses are brick-shaped and range in size in size from 250 to 300nm x200 to 250 nm.

Clusters of these poxviruses can be identified in hematoxylin and eosin-stained sections as intracytoplasmic eosinophilic inclusions.

The poxviruses fall into different subgroups depending on antigenic relationships.

Some of the important poxviruses are as follows:

 1. Orthopoxviruses:

Smallpox (variola)

Monkeypox

Cowpox

Vaccinia

2. Parapoxvirus

Orf

Milker’s nodule (pseudocowpox virus)

3. Molluscipoxvirus

Molluscum Contagiosum