infect

saastuttaa

tartuttaa

tarttua puhekieltä To bring into contact with a substance that causes illness (a pathogen).
{{quote-magazine|year=2013|month=May-June|author=http://www.americanscientist.org/authors/detail/katie-l-burke Katie L. Burke
puhekieltä To make somebody enthusiastic about one's own passion.

(ux)

And in the imitation of these twain, / Who, as Ulysses says, opinion crowns / With an imperial voice, many are infect.