twenties from norfolk county, who had recently traveled to italy with a school group from saint raphael academy in pawtucket, rhode island. the disease went undetected after entering boston, then re-emerged in early march and spread to the state's remaining 13 counties within three weeks. exposure clusters were reported from mid to late march 2020. community transmission began to be reported on march 16, slightly exceeding cases related to travel. cases that had been contact-traced to biogen plateaued on march 13, and were surpassed by local transmissions on march 23. cases of unknown exposure surpassed those of known exposure on march 19, then continued to grow rapidly. when the massachusetts department of public health ceased updating statistics on exposure on march 27, there were 99 cases traced to biogen, 163 cases of local transmission, 93 cases related to travel, and 2,885 cases where initial exposure was under investigation. waves massachusetts experienced a first wave of covid-19 that peaked in late april 2020. the rolling seven-day average of confirmed daily cases peaked at 2,300 on april 20, and average confirmed daily deaths peaked at 175 on april 24. average hospitalizations peaked at 3,874 on april 27. a second wave began in the autumn of the same year and peaked in january 2021, seeing higher daily case numbers but fewer deaths and hospitalizations than the first wave. the spike in cases began in october and, in the first days of december, daily case numbers surpassed those seen at the height of the first wave. the rolling seven-day average of confirmed daily cases peaked at 6,238 on january 8, 2021, and average confirmed daily deaths peaked at 77 on january 28. average hospitalizations peaked at 2,347 on january 7. a third spike in cases occurred in march and april 2021. the state's rolling seven-day average of confirmed daily cases peaked at 2,042 on march 31, and average hospitalizations peaked at 720 on april 8. the third wave resulted in fewer deaths than the previous two, which senator julian cyr attributed to vaccines. a fourth wave began in july and august 2021. another wave occurred in the winter of 2021 to 2022, coinciding with the emergence of the omicron variant in the state, and exceeding the peak number of cases in any previous wave. as of january 13, 2022, massachusetts was experiencing a rolling average of 13,314 new confirmed cases and 43 confirmed deaths per day. tests