presence and prevalence

I heard a news report on the increase of the prevalence of the police in the CBD — and wondered.  I think that, while you can increase the presence of the police force in the CBD, you can’t increase its prevalence.

The word prevalence comes from Middle French and refers to something which prevails, that is, is in strong force in a particular area and a particular time.  Diseases prevail.  Weeds prevail in my garden. They take over from everything else.

But the police do not take over and oust everyone else.  They simply are present in more numbers than usual. They have increased their presence, their representation in a particular area.

Possibly this is a confusion between two words that are close in sound — well, close-ish.  Possibly prevalence sounds stronger than a mere presence. Let’s hope that prevalence will not increase its presence in the lexicon of the news reporters.