From Wikipedia: Tetralogy of Fallot (TOF) is a congenital heart defect which is classically understood to involve four anatomical abnormalities (although only three of them are always present). It is the most common cyanotic heart defect, representing 55-70%, and the most common cause of blue baby syndrome..
Variola (the virus that causes smallpox) is a member of the orthopoxvirus genus, which also includes viruses that cause cowpox, monkeypox, orf, and molluscum contagiosum. Poxviruses are the largest animal viruses, visible with a light microscope.They are larger than some bacteria and contain double-stranded DNA. Poxviruses are the only viruses that do not need a cell's nucleus to replicate inside the cell. The variola virus is the only known cause of smallpox.The disease affects only humans.oxviruses are the only viruses that do not need a cell's nucleus to replicate inside the cell. The variola virus is the only known cause of smallpox. The disease affects only humans.
Smallpox is an extremely contagious and deadly virus for which there is no known cure. The last known case occurred in the U.S. in 1949 and due to worldwide vaccination programs, this disease has been completely eradicated.Smallpox is also known as âvariola.â. Since the time of ancient Egypt, smallpox has proven to be one of the most devastating diseases to humankind.s a result of worldwide, repeated vaccination programs, the variola virus (smallpox) has been completely eradicated. The only people considered to be at risk for smallpox are researchers who work with it in a laboratory setting.