If we could track the spread of diseases and hold those people responsible accountable we could stop disease.
I mean...we know the 4 or so people that brought it to the US right? So they say. Start with them.
The problem though still remains that people can take on more risk then they can ever hope to pay out in their miserable lives. Thus you need a sort of holding company that will pay the debt, and then take ownership of the person and their heirs to pay the debt off. Has to be multi-generation because the loan has to be paid. And oddly enough it provides an incentive for these slaves (for they are slaves until the debt is paid) to be the best they can be not so they can be free but that someday their heirs will be free.
The holding company (which we can call the "state") could then sell a percentage of these slaves to private holders, all reported in a blockchain. You and I could then buy a slave, a percentage of the output of the slave, or possibly one of the slaves' children.
It gets interesting when you think about it. The real fun comes when slaves own percentages of other slaves and everyone is enslaved to everyone else.