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].
What causes syphilis? Bacteria cause syphilis. They usually enter the body through the tissues that line the throat, nose, rectum, and vagina. A person with syphilis who has a sore or a rash can pass the infection to others. An infected pregnant woman can also pass syphilis to her baby. Some things increase your chance of getting syphilis. They include: Having unprotected sex (such as not using condoms or not using them correctly). This risk is high among men who have unsafe sex with other men. Having more than one sex partner and living in an area where syphilis is common. Having a sex partner who has syphilis. Having sex with a partner who has many sex partners.