I was disappointed over the lack of links in a web(!) article, so I did some research over this comment: Poland notes that since then, Lyme has become more widespread and is now the most common tick-borne disease in the country.

Dr. Gregory Poland works in Mayo Clinic which is based in Minnesota. Here are statistics for Lyme disease in that country:

http://www.health.state.mn.us/divs/idepc/diseases/lyme/stati...

http://www.health.state.mn.us/divs/idepc/diseases/lyme/cases...

And for the entire United States: http://www.cdc.gov/lyme/stats/chartstables/casesbyyear.html

Looks like the number of cases is slowly growing. Charts don't seem to be normalized. The increase in cases could be due to increase in population.