With a report Monday of 1,153 new cases of COVID-19, Pennsylvania’s new infection rate increased almost 13 percent, according to state Health Department reports.

Meanwhile, Mercer County’s rate declined week-to-week, although a single-day’s report skewed last week’s figures.

In the seven-day span from Sept. 16 to 22, Mercer County reported 44 new COVID-19 infections. The following week, from Sept. 23 to 29, the county had 39 cases.

However, the Sept. 16-22 figures were inflated by a report of 21 new infections Sept. 17. That was the second-worst day since the virus arrived in Pennsylvania March 6, and worst since the 22 new cases on Aug. 12.

Had the number of reported infections matched the average, 4.7, from the other 13 days over the last two weeks, the Sept. 16-22 case count would have been less than 30.

Mercer County’s total number of COVID-19 cases, as of Wednesday, is 744, with 666 confirmed cases and 78 probables.

The Health Department lists the county with 20 fatalities. That figure includes seven deaths in September, the county’s worst month for fatalities.

Mercer County’s fatality and infection rates have been swelled by reports of 76 cases and 10 fatalities, according to the Health Department, at the Grove Manor long-term care home in Grove City.

The Grove Manor outbreak has also had an impact on a spike last month in the Grove City ZIP Code. In September, Grove City’s case count increased more than 60%, from 101 to 166 since Sept. 8.

In Mercer County, September was roughest on Grove City, but Mercer borough was also hit hard, with an increase from 95 to 125 (32%). Cases in Greenville increased 41%, from 39 to 55 during that stretch.

On the other hand, towns in the Shenango Valley appear to have flattened the curve. Farrell had experienced a spike that contributed to the Health Department’s decision in May to delay Mercer County’s move from red to yellow in Gov. Tom Wolf’s red-yellow-green reopening protocol. Since Sept. 8, the city has had only one new case, bringing its total to 43.

Cases in Hermitage increased 19%, from 100 to 119, Sharon went up 27% from 62 to 79 and Sharpsville increased 27% from 33 to 42.

With Wednesday’s report, the state’s total case count increased to 158,967. The Health Department reported 19 new fatalities, setting the total deaths at 8,142.