Family: Poxviridae
Subfamily: Chordopoxovirinae
Class: Orthopoxvirus
Genus : Poxvirus species: Smallpox (Variola)
Special physical structures
• Double-stranded DNA virus
• Linear molecular structure with complex morphology
• Unique enveloped large brick shaped
• Obligate Intracellular Parasite
Unusual genes or toxins • Poxvirus is one of the largest viruses that contain several subfamilies such as cowpox, monkeypox, vaccinae, orf and molluscum to name a few with smallpox being the most endemic of all
•Poxvirdae is one of the largest viruses and one that is a human pathogen that is deadly and was an epidemic that haunts medical professionals to this day
• Smallpox virion consists of approximately 187,000 nueclotides which makes it one of the largest viruses to go through transcription and translation in the genetic code sequence
• Smallpox virion has a helical nucleocapsid that resembles a dog bone or a dumbbell shape
Other unique characteristics
• Smallpox is considered a category A agent, which can cause a widespread disease epidemic such as Anthrax, plague, botulism, tularemia, and viral hemorrhagic fevers
• Ordinary form, confluent form, and hemorrhagic form
History
• Smallpox arrived with the European settlers to the New World in the early 1600s, which wiped out about 90% of American Indians but dates back to Egyptian times in B.C.
• Edward Jenner’s discoveries in 1796 in the vaccination using cowpox lead the path to smallpox vaccination that eventually lead to the eradication of smallpox in 1980, the last case ever known was in Somalia, Africa in 1977
• The last outbreak in the United States was in 1949 Transmission & Life cycle
•Transmission of smallpox was person to person contact or by inhalation of the particles in the air of infected people or through the sharing of bedding /clothes
• Viral multiplication is through transcriptase where the components of the virus are
References: Tortora, Funke, and Case. Microbiology an Introduction, 10th ed Ch.13. Pearson Education: San Francisco, CA, 2010 Preston, Richard World Health Organization, 2001. Smallpox Introduction. http://www.who.int/mediacentre/factsheets/smallpox/en/ Citable reviews in the Life Science, 2010 http://www.ppdictionary.com/viruses/smallpox.htm Center for Disease Control, 2007