Records of the Massachusetts Department of Public Health show that on March 1st, three cases of COVID-19 had been reported in Massachusetts. By the end of March, more than 100 new cases were being confirmed every day.
The three charts below display the counts of new cases and deaths in Massachusetts, along with the percentage of COVID-19 tests reported as positive. These measures are indicators of the spread of the disease, and each indictor peaked in April and has been steadily declining since then.
Massachusetts embarked on Phase 1 of the Baker-Polito plan for “reopening the economy” on May 18, Phase 2 on June 8 and June 22, and Phase 3 on July 6, which are highlighted on the charts by vertical yellow bars.
Technical notes: On June 1, the Mass. DPH began combining confirmed and probable cases when reporting the number of new daily cases and total number of COVID-19 cases for the commonwealth. Subsequently, the DPH began reporting only confirmed cases again on the daily dashboard, while including both confirmed and probable cases in the raw database used to update the case-count chart below. The probable cases account for the difference in the total number of deaths reported in the chart above and on the dashboard for the same date at https://www.mass.gov/info-details/covid-19-response-reporting. The raw data files containing COVID-19 related deaths updated daily by the DPH are not as current as the raw data files containing case-count data, which explains the discrepant dates on the charts above depicting cases and deaths.
Analysis: The percentage of tests reported positive peaked on April 13; the daily increase in new cases peaked on April 17; and the daily increase in deaths peaked on April 24. This sequence follows the pattern epidemiologists expect. Positive tests are a leading indicator, while numbers of deaths are a trailing indicator. Testing must be performed to confirm cases, while death usually follows diagnosis by a week or two. The number of new COVID-19 cases was 157 at the start of Phase 3 and hit 540 on July 30, which was the highest daily new case count since early June. This recent upward trend in the spread of COVID-19 is particularly evident in the daily counts of new cases in individual counties. See OTHER COUNTIES.
Effect of reopening: The recent increase in spread of COVID-19 in Massachusetts may be a result of the less restrictive set of rules associated with Phase 3, failure of residents to follow the rules, or both.