Massachusetts town-by-town COVID-19 cases

The Massachusetts Department of Public Health started publishing, on April 14, 2020, epidemiological data for each of the Commonwealth’s 351 cities and towns. The results come out once a week each Wednesday. They publish them in .pdf and .docx format. And, they don’t keep previous weeks’ data on their web site.

Here is a .csv file containing  all the data they’ve published. Thanks to Boston.com for keeping previous weeks’ data available.

What’s in this file?

  • date: the date of the report from Mass DPH
  • town: the name of the municipality
  • cases: cumulative number of COVID-19 cases in the municipality. In the .csv file this value is missing where there are less than five cases to report. That’s to preserve patient confidentiality in small towns.
  • rate: the number of cumulative cases per 100,000 population. This value too is missing where there are less than five cases to report.

I believe the cases and rates are cumulative, and do not reflect patient recoveries or deaths. So, they are not current case loads. The DPH numbers come from actual case counts. They do not include people who became ill and were never diagnosed.

The DPH reports say this at the top:

Please note: Data for these tables is based on information available in the DPH surveillance database at a single point in time. Case counts for specific cities and towns change throughout the day as data cleaning occurs (removal of duplicate reports within the system) and new demographic information (assigning cases to their city or town of residence) is obtained.

And, at the bottom they say this:

Data are current as of 12:00 pm on [the date of publication]. For populations <50,000, <5 cases are reported as such or  suppressed for confidentiality purposes.

Bureau of Infectious Disease and Laboratory Sciences calculates rates per 100,000 population using  denominators estimated by the University of Massachusetts Donahue Institute using a modified Hamilton-Perry model ( Strate S, et al. Small Area Population Estimates for 2011 through 2020, report published Oct 2016.)

[The town is marked as ‘Unknown’ when] address information for these cases are currently being obtained.

I will scrape each new DPH report each Wednesday evening and update the .csv file. It’s now updated to 4-June-2020.

Use this data as you will, but please keep in mind that it comes from DPH not me. Please give them appropriate credit. I may have made errors scraping it. Caveat lector.

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