This is another update that breaks down case and testing statistics by city and town in Massachusetts based on data published in the state’s weekly public health report. In the original community spread post https://www.masscoronavirus.net/community-spread-in-massachusetts-september-26-2020/ I outlined some of the issues with the community data in the weekly report, and described my methodology for calculating how a particular city and town has contributed to the change in either case incident rates or test positivity rates in the state.
|Table 1: Highest Case Incidence Rates and Contribution to Case Incidence Increase|
|Period Ending November 14, 2020|
|Highest Case Incidence Rates||Largest Contributors to Weekly Case Incidence Increase|
|City/Town||14 Day Case Count||Daily Case Rate per 100,000||City/Town||14 Day Case Count||Daily Case Rate per 100,000||% Contribution|
Statewide case incidence rates have more than tripled from four weeks ago when I wrote my last update, highlighting the rapid spread of covid throughout Massachusetts during that time. The list of communities with the highest incidence rates is varied:
(1) relatively small towns such as Tisbury and Marion,
(2) previously identified hotspots such as Lawrence and Lowell,
(3) and communities with large institutional complexes such as the prisons at Norfolk and Shirley. The state has stopped putting asterisks on those communities in the weekly report – a notational change it started several weeks prior.
Overall, only 31 of the 351 communities in the Commonwealth had no cases in the two weeks ending November 14, and only 34 communities have seen a decrease in cases from the previous report. The largest community with no cases is Provincetown, population about 2,600.
95% of the state’s population lives in communities which would have been labeled as red zone under the original labeling guidelines that were relaxed last month. This is up from 71% just two weeks ago. I noted this labeling change and calculated its impact in a post about two weeks ago (https://www.masscoronavirus.net/massachusetts-reporting-change-november-6-2020/ ).
As I’ve indicated in prior posts, the communities having the largest impact on the week over week increase in the statewide incidence rate tend to be either very large (e.g., Boston), have had large increases in cases (almost all), or both. The smallest community on the list is Peabody, population of about 56,000. Note that only Cambridge has a incidence rate below the statewide average.
|Table 2: Highest Positivity Rates and Contribution to Positivity Rate Increase|
|Period Ending October 17, 2020|
|Highest Test Positivity Rate||Largest Contributers to Weekly Positivity Rate Increase|
|City/Town||14 Day Test Count||Test Positivity Rate (%)||City/Town||14 Day Test Count||Test Positivity Rate (%)||Relative Impact (%)|
Table 2 focuses on testing statistics throughout the state. The communities with the highest positivity rates for the last two weeks are similar to those with the highest case incidence rates, since raw testing figures tend to correlate highly with population (95% correlation for testing over the past two weeks). The one notable exception is Tolland, which had 1 positive case and 9 tests, resulting in a positivity rate of 11.1%.
The ten communities with the largest impact on the statewide positivity rate increase are the same as the communities with the largest impact on the statewide case incidence increase with one exception – Everett has replaced New Bedford. But Everett was 11th on the case incidence list, and 10th here, so this is not a big change.