The other day I came across this alarming video of what it’s like to drive in Poland. My first thought after watching the clip was “What’s the Toxoplasmosis gondii infection rate in Poland?” T. gondii is a brain parasite easily acquired from eating undercooked meat, or contact with cats, and is associated with a six-fold increase in traffic accidents (this association has been replicated a number of times, in different countries). Well, I looked it up, and found that the latent infection rate in 2003 was around 41% (at least among pregnant women). That’s quite high — in the U.S. the infection rate is only about 11%.
Is there anything to my hypothesis that terrible driving in Poland is related to the relatively high T. gondii infection rate? Probably not. The accident fatality rate in Poland is relatively high for a modern industrialized country. But France has a very low accident fatality rate, and a much higher rate of T. gondii infection. So while T. gondii might be a contributing factor, it’s probably not the most important variable.
I’m fascinated by latent/chronic biological infections, and how they affect human health and behavior. T. gondii in particular is linked to changes in personality, and even schizophrenia.