The most likely groups that could be a problem regarding Ebola in the U.S.

People who are illegal aliens without the legal right to be in this country and afraid of being deported back to where they came from likely wouldn't choose to go to a hospital unless they thought they were dying and might not even then.

They could be from everywhere on earth but would be more likely right now to be from West Africa at this point at least in the progress of infections of Ebola.

So, if Ebola gets loose this group along with people who are wanted criminals would be the most likely to avoid hospitals and avoid seeking medical help here in the U.S.

So, if even one of these folks got Ebola it could spread throughout these kinds of groups before it spread to the general populace.

Also, if someone was infected and was sent to prison a whole prison population might be infected with Ebola before people understood what was happening too.

Also, any groups of homeless people or other groups in the U.S. who don't believe in western medicine or hospitals could also spread the disease. However, people who believe in western medicine and believe it might save them no matter what group they are might go to a hospital to make sure they don't die or infect others too.