I found a glossary of some terms we have been hearing recently, and was the gist of what I was getting at regarding being careful about our choice of words, like "exposure," because they imply different levels of risk.

I'll paraphrase a bit:

A "contact" is someone who spoke to, touched, or was in promixity to a patient. Further follow up is necessary to determine what kind of interaction might have happened with the patient and what kind of risk the person is in.

An "exposure" is contact that puts a person at high risk of the disease, such as direct contact with bodily fluids without protection.

The list of contacts to Mr Duncan is around 100 as I write this, but the list of exposures is maybe a dozen or a bit more.