This is the most basic public health prevention measure. You make sure that all folks entering a disaster zone are clean. There was a reason we used to quarantine immigrants. Do you really think that the risks have gone away?
You should also do the same for those leaving. Fortunatley testing has mostly eliminated the actual need but it must be rigorously applied.
Quite simply someone bungled and if procedures do not exist, then the head of the agency needs to resign. Someone somewhere failed to do his job and is guilty of negligent manslaughter. Since 10,000 died, he has committed a crime against humanity as well..