Smallpox Causes. 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.urvivors of smallpox often have severely deformed skin from the pustules. 1  Types: Variola major, or smallpox, has a death rate of 30%. 2  Variola minor, or alastrim, is a milder form of the virus with a death rate of 1%. 3  Four types of variola exist: classic, hemorrhagic, malignant, and modified.
This means that even when condoms are used properly, syphilis can still be spread if the sore is located in an area not covered by the condom. Because sores can be located on the lips and mouth as well as the external genitals, vagina, anus, and rectum, there are many possibilities for transmission. [5].
How Syphilis Is Spread (Watch Out for Sores!). In acquired syphilis, the bacterium enters the body through skin or mucous membranes, usually during sexual contact. It can be spread from the sores of an infected person to the mucous membranes of the genital area, the mouth, or the anus of a sexual partner.The bacteria are very fragile, and the infection is not spread by contact with objects such as toilet seats or towels.t can be spread from the sores of an infected person to the mucous membranes of the genital area, the mouth, or the anus of a sexual partner. The bacteria are very fragile, and the infection is not spread by contact with objects such as toilet seats or towels.