As I wrote yesterday, MA is no longer reporting good data to the CDC on Lyme disease. Starting in 2019, however, MA has been publishing tick-borne disease reports. They include this misleading chart:

The caption includes "Although there are differences in the rate of patient visits, this shows that people are exposed to ticks throughout all of Massachusetts and should take recommended steps to reduce the chance of being bitten."

One issue is that they've chosen to chart the rate of visits and not the rate of diagnoses, but the main issue is that the scale hides the degree of variation between counties. Pulling the numbers and manually dividing by population estimates, I see:

The rate in the Islands (Dukes and Nantucket Counties) is 10 times any other MA county!

(Even though these are also vacation areas, people are categorized by their home county not their infection county.)

Now, I agree with them that taking precautions is worth it when walking through tick-friendly terrain anywhere in the state. But there are still degrees of precautions, from clothes, to tick checks, to choosing different activities, to choosing other counties, and the report should emphasize the difference in risk so people can make good decisions.

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