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 caused by a virus and can result in one of two forms of the disease, called variola major and variola minor. Variola major kills 20 to 40 percent of unvaccinated people who get it and can lead to blindness. Variola minor, a far less lethal form of the disease, results in death only on rare occasions.he earliest evidence of smallpox skin lesions has been found on the faces of mummies from the eighteenth and twentieth Egyptian dynasties, and in the well-preserved mummy of Pharaoh Ramses V, who died in 1157 B.C.E. The first recorded smallpox epidemic occurred in 1350 B.C.E., during the Egyptian-Hittite War.