In this case, a living person would also pose a risk. These islanders don't have the same immune system that the population the health professionals are looking after have, just like Native Americans didn't have the same immune system as Europeans.
It's not comparable to the "New World" situation. These islands are close to the continent and had regular (if dangerous) visits from modern people throughout the twentieth century. We have no reason to think that Chau carried a deadly disease.
