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.
Molluscipoxviruses include the human poxvirus, molluscum contagiosum virus. Smallpox and molluscum contagiosum are specific to humans. The other viruses cause rare zoonotic infections in humans. Vaccinia virus, which has been used for vaccination, can also infect humans.Infections due to poxviruses have dated back to antiquity. The first evidence of smallpox was found in Egyptian mummies of the 18th Dynasty (1580-1350 BC).Variola became endemic in India in the first millennium BC and spread to Asia and ultimately to Europe in the eighth century.he other viruses cause rare zoonotic infections in humans. Vaccinia virus, which has been used for vaccination, can also infect humans. Infections due to poxviruses have dated back to antiquity. The first evidence of smallpox was found in Egyptian mummies of the 18th Dynasty (1580-1350 BC).