I was with a high mileage SP a few years ago, who, when I asked about her STD status, became very angry. She refused to answer the question, "when was the last time you got tested?". I took her anger as a very negative response, and her only words were "I hate that question". I surmised that she had never ever been tested, and that the anger came from being asked that question by many others.
Having been at this a few years and having come to know a few SPs personally, I would have to say that MOST of the ones I've encountered have never been regularly tested, and a great fraction of those have never tested at all. The mentality is that they are afraid to know, and believe that if they confine themselves (with the odd transience) to a few activities, they will probably not ever catch anything. The trouble is, they have unrealistically appraised the risk of those activities. Now having dated (ie: non-professionally) my 3rd SP, I can attest that this attitude is common. Furthermore, most lie about being tested. For example, I went along with two SP-GF's to their doctor, and found out that they had never been tested at all.
The ignorance of those in the SP "profession" is astounding. They are not only ignorant of the facts, but choose to ignore it when presented to them. Why? Greed and laziness.
A sobering epiphany may never occur to most. The money is too astoundingly good, the work too easy that they don't wish the dream to end. They don't want to face that the world is still a place where those who work hard are the ones who deserve the rewards.
Of course, there are exceptions to all this, and I personally know some. That they exist is a testament to the intelligence and wisdom of some women. But it is sad to say that they are grossly outnumbered by the dummies.