Search Engine Land reports that Google added an OneBox for health-related information that's only displayed in the US. If you search for [flu], [ADHD], [autism] and other medical conditions, you'll see an excerpt from a Google Health article and links to other services: Mayo Clinic, Medline Plus, WebMD.
Most likely, some of the keywords that trigger the OneBox are displayed on this page. Google Health's articles combined information licensed from reputable sources with information from scholar papers, news articles and other web pages.
19 minutes ago