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 caused by a bacteria called Treponema pallidum and is transmitted sexually. Upon entering the body, the bacteria starts acting on the nervous system as well as body organs, the main one being the heart.n most cases, the causes of the sore show the location where the syphilis entered the body. The sore is firm, round and does not cause any pain. The sore can go unnoticed because it is painless.