And so that animal is still a source of transmission.

Why is this the transmittable disease whose transmission equates to criminality?

By ensuring early detection, early reporting, early quarantine and early treatment, we have done everything possible to control infection source.

These carriers deliver the bacteria to all types of farms -- regardless of whether they're conventional, organic or free-range.

In countries where measles has been largely eliminated, cases imported from other countries remain an important source of infection.