Friday, November 03, 2006

That furry feeling

Are cat lovers sick?

Toxoplasmosis is disease caused by a parasitic protozoan. The life cycle the protozoan is aiming for goes from cats to soil to rodents to cats. When rodents are infected with toxoplasmosis their behaviour changes: their reaction times are slowed and they are attracted to (rather than being repelled by) the smell of cats. This is clearly a good thing for the protozoan as it makes the rodents it infects more likely to be eaten by cats.


In the life cycle of the protozoan it is easy for things to go wrong. Many other animals, not just rodents, can become infected from the soil. Humans can become infected either from eating imperfectly washed vegetables grown in soil with toxoplasmosis oocysts in it or from eating inadequately cooked meat from animals who became infected from such soil. Recently studies have been done that show that people infected by toxoplasmosis also have slower reaction times and much higher car accident rates.

When I was pregnant I realised that if toxoplasmosis is common in NZ then I have it - I grew up with cats who hunted and a vege garden. What I wonder is, there are clearly people who are drawn to cats, is this also an effect of toxoplasmosis? If you tested people who grew up with cats but are not 'cat people' would you find that they are not infected?

Am I infected because I'm a cat person or am I a cat person because I'm infected?

5 comments:

JK said...

Interesting, didn't know about the slower reaction times... very interesting.

I've never been tested, but they can do that to see if you have it. I probably had it as a kid 'cause of our cat and his hunting. I used to change the litter box as a small kid.

Toxoplasmosis can go away on its own... right? The real danger is if you're first infected while you're pregnant I thought... http://www.cdc.gov/NCIDOD/dpd/parasites/toxoplasmosis/factsht_toxoplasmosis.htm

JK said...

Oops...link didn't work...

http://www.cdc.gov/NCIDOD/dpd/parasites/toxoplasmosis/factsht_toxoplasmosis.htm

JK said...

Oh...

It doesn't go away...

from...Kid's Health


Once a person has become infected with toxoplasmosis, the infection remains in the body for life, usually in a latent (inactive) form that won't cause the person any side effects or harm. The infection can be reactivated, however, if the immune system becomes compromised by an HIV infection or cancer therapy.

JK said...

In case you hadn't guessed from all the links, now you made me a little paranoid about toxoplasmosis ... oh well, I'm sure in about an hour I'll be dealing with too much other stuff to think about it more.

RUTH said...

The behaviour changes are observed in subjects (rodents and people) with latent toxoplasmosis. Here is a search from Google Scholar. Before you get too paranoid consider: a) 80% of French people have latent toxoplasmosis, b) if you're anything like me most of your friends will also be cat lovers too, c) you're unlikely to be eaten by a cat and pass it on.