Massachusetts Known COVID-19 Cases vs Tests


Massachusetts Known COVID-19 Cases by City/Town as of November 19

Percent positive is for the previous 14 days. In positive rank, a higher number (i.e. 300 or more) is a preferred data point.




Massachusetts Known COVID-19 Deaths

Massachusetts Known COVID-19 Hospitalizations

MWRA's wastewater testing detects virus levels in sewage and offers a way to detect Covid-19 infection trends before testing of individuals.

Infrastructure provided by Digital Ocean.

MWRA Wastewater Covid-19 Tracking

MWRA's wastewater testing detects virus levels in sewage and offers a way to detect Covid-19 infection trends before testing of individuals. Note: You can click and drag on an area of the graph to zoom in.

Only communities in eastern Mass that are part of the MWRA sewage systems are included. To see additional MWRA testing data, go to the Massachusetts Water Resources Authority website

Note: Biobot, the external private lab running the testing, changed its data processing protocol on Nov. 17. The graph below reflects the new protocols, but does not include confidence intervals and error bars now available. Please go to the MWRA site to see those.



Most of this data come from the Massachusetts Department of Public Health Web site. You can go there now to see the latest official state dashboard. Some historical data, including deaths, comes from the New York Times GitHub repository. Note that the Times data includes probable cases from serology tests but I don't include that when reporting Mass DPH data, since I am more interested in seeing current trends than overall infections (serology tests can be positive for someone who was contagious weeks ago but is recovered). MWRA wastewater testing comes from the pilot project with Biobot; more info and raw data available from the MWRA.

Massachusetts changed its data-reporting format on April 20, so I am no longer able to report detailed demographics of fatalities.

As with all U.S. Covid-19 data, these tables and graphs are undercounting the actual number of cases. That's due to the inadequate testing. While testing rates have improved, some cases are still being missed.

We also didn't know how many tests have been performed in Massachusetts until March 23. Before then, some private laboratories were only reporting positive results. That meant the total number of tests was somewhat higher than being reported.

This application was created by Sharon Machlis with the R programming language and R packages shiny, data.table, ggplot2, plotly, leaflet, DT, and glue, among others. It wouldn't have been possible without the incredible contributions of the R core team and R package authors to make this free platform possible. (Any and all errors in the data presentation are, however, mine alone.)

Infrastructure provided by Digital Ocean.