article_snippet: Most cases are tied to an outbreak at Disneyland in California, which likely began with a traveler who brought it in.
article_snippet: However, the exact source of the Disneyland-linked cases is not known.
article_snippet: People just don't understand that these diseases are all there, People're not gone.
article_snippet: People're just being kept at bay right now.
article_snippet: If people stop vaccinating, people come right back,' Frenck said.