I had Scarlet fever as a child in the 50s. I don't know of anyone who's had this disease in at least 20 years. Do kids get it anymore? If not, why not? I don't recall my son getting a vaccine against it, but I could have forgotten.
Scarlet fever is a result of a strep infection which is bacterial. It's caused by a toxin the bacteria produce if the infection is left untreated. Kids still get it but not so much anymore with the use of anti-biotics to control the infection.
http://www.kidshealth.org/parent/infections/bacterial_viral/scarlet_fever.html
Yeah people still get it. It's caused by a particular strain of Streptococcus. We are much better about diagnosing Strep and treating it with antiobiotics now. Also the particular strain of strep that causes the scarlet fever rash seems to be less common these days, same for the one that causes Rheumatic Fever. No one knows why.