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].
Syphilis is serious â but it can be cured. Syphilis is a really common STD. Syphilis is spread through vaginal, anal, and oral sex. Syphilis causes sores on your genitals (called chancres). The sores are usually painless, but they can easily spread the infection to other people. You get syphilis from contact with the sores. A lot of people with syphilis donât notice the sores and feel totally fine, so they might not know they have it.