Orthopoxvirus inclusion bodies are aggregates of stable protein produced by poxvirus virions in the cell nuclei and/or cytoplasm of epithelial cells in humans. They are important as sites of viral replication. [1] [2]
Morphologically, there are two types of Orthopoxvirus inclusion bodies: Type-A inclusion bodies and Guarnnier bodies. Type-A inclusion bodies are found only in certain poxviruses like cowpox. [3] Guarnnier bodies are found in all poxvirus infections and their presence is diagnostic. [4] The diagnosis of an orthopoxvirus infection can also be made rapidly by electron microscopic examination of pustular fluid or scabs. However, all orthopoxviruses exhibit identical brick-shaped virions by electron microscopy. [4]
Guarnieri bodies are named for Giuseppe Guarnieri (1856–1918), an Italian physician who first described them. [5]