Image courtesy of the Department of Public Health

After climbing during late July, the seven-day weighted average positive test rate hit its lowest-ever observed level at 1.5 percent on Tuesday, public health officials reported in their daily data update Wednesday.

The latest report updates the comparisons offered for four of the main statistics to track how each has changed from a lowest observed value rather than changes since the mid-April peak, a step that will allow easier comparison for current trends.

Average active hospitalizations were at 396 in Wednesday’s report, 10 percent higher than the low observed in late July. DPH confirmed 229 more cases of COVID-19 for Wednesday’s report and 18 additional deaths, bringing the overall toll since the outbreak began to 8,547.

In the newest report, public health officials also upgraded their projections of the state’s contact tracing capabilities from a yellow dot meaning “in progress” to a green dot meaning “positive trend.” The report did not outline any explanation or additional information about the change, which brings the total number of key metrics the Department of Public Health describes as positive trends from three out of six to four out of six.

The report also added several towns and cities to its “red” category signifying the most severe COVID-19 hot spots in its weekly map of caseloads by town. Fall River, Holyoke, Granby, Lawrence, Salem and Saugus joined Chelsea, Everett, Lynn and Revere.

Gov. Charlie Baker has argued that communities in the “green” and “white” categories – those with the lowest case loads – should be safe to reopen schools in the fall with in-person or hybrid remote and in-person learning.