Why Are We Knowingly Allowing Deadly Diseases Into America

Private Companies are sending their employes into Countries that are having outbreaks of Deadly Diseases that have no readily available treatment/medicine and then want to bring them back to the US with the Deadly Diseases
To start off with I feel sorry for anyone that contracts a Deadly Disease that has almost 100% Death Rate. I feel sorry for anyone who is sent into an area by their Government, that is experiencing the spread of any Deadly Diseases, but I don't feel sorry for a person who knowingly places themselves into the same area for Profit and then contracts the Disease and expects to be returned to the USA for treatment of a Disease that there is no safe way to treat them without exposing the spread of the Disease. If we keep bring Ebola infected people into the US, it is just a matter of time until there is an accidental or intentional release of this Deadly Disease into the wild/general public. With the Large Homeless population in this Country an outbreak of any Disease like Ebola would be Devastating .
The people that are willing to go to these areas need to determine just how much their Life is worth and make the company pay that money into a secure account that their loved ones will have access to in-case they are killed or not allowed to return to the US because of a contracted Deadly Disease.