A lot of unofficial reporting is being leaked because the Chinese government has clamped down on any unofficial social media. There have been not enough testing kits to determine it it's a positive result or not. If they don't get tested it could still be positive but not officially counted. In other words no one knows how many have it right now.

Second, in the US only 3 states have the ability to test as of yesterday. So even if you do go to a hospital you could be carrying the virus and they would not have a clue.