Hey, what can I say? Modern media likes to sensationalise everything. <shrug>
While I agree that in an ideal world more precise language by the presenter may have been educationally helpful, after reviewing I wonder if that was not a deliberate ploy to keep the viewer attention focussed in a field where most people have little knowledge or often interest.
By the way, your statement that she is "
completely wrong" in your attempt at dismissal is just you falling into a similar trap to her, assuming her words were not deliberately chosen. Here is the Oxford dictionary definition of contagious:
Definition of contagious in English:
contagious
Pronunciation: /kənˈteɪdʒəs/
ADJECTIVE
1(Of a disease) spread from one person or organism to another, typically by direct contact:
And general 'googly' type definition:
contagious
kənˈteɪdʒəs/
adjective
1.
(of a disease) spread from one person or organism to another, typically by direct contact.
"a contagious disease"
synonyms: infectious, communicable, transmittable, transmissible, transferable, spreadable; More
So her use of the qualifying word "highly" could mean that it is an infectious disease
almost exclusively spread by contact, in this case blood to blood contact. Of course if she had used "very" to qualify then she would have been wrong.
English is such an imprecise language. <sigh>