A Few Fun Facts


The poxvirus genome consists of covalently bonded double-stranded DNA containing 130-375 kilobase pairs. The genome is linear,noninfectious, and encodes for over 100 genes.


The morphology of the poxviruses is classified as "complex", and the nucleocapsid can be ovoid or brick-shaped. Electron micrograph reveals the complex coat of tubular structures that help identify poxviruses.

A negatively stained poxvirus courtesy of the creators of http://www-micro.msb.le.ac.uk/335/Poxviruses.html

Diseases & Clinical Features

Smallpox (variola major & minor): The incubation period is 10-14 days, and the onset is acute, with fever, malaise, headache, and backache. A pustular rash develops in which the rash is most profuse on the face, abundant on forearms, but less in lower legs, thighs, and trunk.

Vaccination Complications: Four to five days after vaccination, a papule appears. In most patients, the pustule dries from the center outward, leaving a characteristic scar. However, in some rare cases, immunocompromised individuals or those suffering from eczema may suffer a general vaccinial rash, that can prove even fatal in those whose immune system is severely hampered.

Monkeypox: Symptoms are similar to smallpox, but viral entry in primary infection most likely comes through skin lesions or orally.

Molluscum Contagiosum: The incubation period is 14-50 days. These lesions appear pearly, flesh-colored, raised, and are "umbilicated", and there is often an opening at the top of each nodule where a white core is visible. The lesions are painless, and often heal spontaneously.

Cowpox: These lesions appear as scratches or abrasions, usually on the hands. A vesicle, pustule, then scab forms on skin.

Yabapox: Rarely, large "protuberant" tumors can be seen in humans if there is accidental exposure to the virus.

Tanapox: Nodules develops into papular rash, and lesions ulcerate in the third week. The lesions are usually solitary on arm, face, neck, and trunk.

History Replication Updates Useful web links References


Reyna Fuentes

Humans and Viruses
Human Biology 115A
Winter, 1999
Robert Siegel, instructor

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Created: March 5, 1999
Last modified: March 5, 1999