Why do STDs and STIs exist?

That superstition is bolstered by anti-science conspiracy theorists. Do a Google search for "AIDS denial." There are many, many people who believe that STIs do not exist--they're made up by evil doctors and "Big Pharma" in order to scare and control people. read more

For the same reason that influenza, cholera, diphtheria, tuberculosis, the common cold, and scarlet fever exist: because disease organisms have evolved to take advantage of those vectors. read more

Sexually transmitted diseases (STDs) are passed from one person to another through intimate physical contact – such as heavy petting – and from sexual activity including vaginal, oral, and anal sex. STDs are very common. In fact, CDC estimates 20 million new infections occur every year in the United States. read more