October 15, 2009

More on HPV

A couple of excellent science bloggers have taken the time to fill in some of the details around HPV and the vaccines that I left out in my self-preoccupation. PalMD did a great job of putting my situation into the context of regular screenings.

When a woman lays back on the exam table at her yearly exam, the doctor or nurse first looks at the outside of the vagina for any abnormalities such as external yeast infections or genital warts. They then open up the vagina with a speculum and can see the vaginal walls, and eventually the cervix, which at this angle looks a bit like a think donut. Depending on technique, a small, cylindrical brush is inserted into the cervix and rolled around to collect cells, and a wooden spatula is scraped around the outside of the cervix. Then the speculum is removed, and fingers are inserted internally and a hand is pressed against the pelvis to feel for any other abnormalities. Usually a finger is also inserted into the rectum to feel the tissue between the rectum and vagina.

If all this sounds rather invasive, it is. Some women have very little sensation in their cervix, but many women have a very sensitive cervix and yearly pelvic exams can be very, very unpleasant. For women with a history of physical/sexual abuse, the discomfort can be magnified a thousand-fold. So if you're wondering how a woman could possibly fail to get a regular Pap smear, try a little empathy. In medicine, we find it tempting but ultimately not useful to blame people for their diseases.

Empathy is one of Pal's strong suits, and there's plenty to be found in his post, even though I told him not to worry about my feelings or privacy in getting his message out. Which he did.

Abbie at ERV also wrote a post that made my unforgiving self very happy. (What? It's a virus. It doesn't care how I feel about it.) She explained why the vaccine can do permanent good--why we don't need to be too concerned about another HPV strain taking over and causing the same number of cancers as the vaccine prevents.

There is no adaptive advantage to an HPV that causes cancer.

It could be that 'any' HPV can cause cancer, by accident, its just that HPV 16 and 18 are the most prevalent HPVs, so they get the most 'chances' to make a mistake.

But thats not the case. 16 and 18 cause a teeny-tiny minority of all HPV infections.

Getting rid of them is not going to create an ecological vacuum that will necessarily be filled. While 'shit might happen' again, there is no evolutionary 'reason' to fill the 'HPV cancer' void.

Get your vax against HPV 16 and 18. Obliterate those assholes from the planet.

What she said.

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