South County had the highest concentration of COVID-19 cases in St. Louis County for the last two weeks, continuing a disturbing trend that started in the summer but has become more noticeable heading into winter.

In cases per 100,000 people in the last 14 days, South County’s ZIP codes of Oakville 63129, Concord 63128, Sunset Hills 63127, Crestwood 63126, Affton 63123 and Lemay 63125 tallied the highest number of cases per 100,000 of population in the county, next to nearby areas that are also near Jefferson County like Valley Park and Fenton.

“The highest concentration of cases is in South County, south St. Louis County, we know that,” said County Executive Sam Page Nov. 30. “We see less masking compliance in general in South County, but we’re getting there —  the community is responding, and we know that they want to do what they have to do to protect their families and their loved ones. But we do recognize that COVID is being transmitted at a much greater rate in South County, and we hope to continue to get more compliance with our public health orders in that part of our community.”

Early in the pandemic, North County saw the highest case numbers, but in the last few months South County has consistently reported the highest case numbers in the county and has repeatedly been singled out by the St. Louis Metropolitan Pandemic Task Force for racking up the highest numbers of cases per ZIP code.

The highest totals for cases also extends to Mercy Hospital South having the highest number of COVID-19 cases per bed in the Mercy system and perhaps the St. Louis region, said Mercy South Chief Medical Officer Dr. Aamina Akhtar.

St. Louis County set a record for number of daily new COVID-19 cases Nov. 15 with 815, and in numbers updated Nov. 23, the largest number of new positive tests were in South County, which had 91.3 cases per 100,000 diagnosed per day, compared to rates of 72.2 per 100,000 in West County, 69.7 in Outer North, 65.3 in Central and 55.6 in Inner North.   

The positivity rate is highest in South County at 23.2 percent, followed by Outer North at 19.1 percent, West at 17, Inner North at 16.8 and Central at 13.2 percent.

The same report showed that while South County has higher case counts and positivity rates, it has lower rates of testing than other areas in the county.

Central County and West County had higher rates of testing going into Thanksgiving, with South County ranking in the middle of the county’s regions.

As of Sept. 14, the county had received 37 percent of its complaints about businesses not enforcing the mask mandate in South County, compared to 34 percent in North County and 29 percent in West County.

The county did not respond with updated data last week.

The reason behind the higher case numbers in South County could trace back to geography: The highest numbers within South County have consistently been reported in Oakville’s 63129 and Concord’s 63128 ZIP codes, which are close to Jefferson County.

That was true at the time of St. Louis County’s last two-week report heading into Thanksgiving, when all the darkest areas of the county were in South County, signifying the highest numbers of cases.

All South County ZIP codes were ranked with the highest numbers in the county: Oakville 63129, Concord 63128, Crestwood 63126 and Sunset Hills 63127 all ranking between 1,257 and 2,688 cases per 100,000. The 63123 and 63125 ZIP codes of Affton and Lemay ranked slightly lower at 1,046 to 1,257 cases per 100,000.

Arnold and Jefferson County have also repeatedly been singled out by the task force as having the highest numbers of cases per ZIP code alongside Oakville and Concord, and Jefferson County has gone in and out of the “red zone” but had not taken any countywide measures to stop the spread of the virus until late November. After months of debate, Jefferson County finally implemented a mask mandate Nov. 25.

Page said he believes that mandate could help efforts to combat the virus within St. Louis County’s borders.

“There is a lot of back and forth between South County and Jefferson County — we believe that their recent mask order will help us a great deal,” Page said.

The science behind face masks is indisputable after multiple studies have shown they work, but has been damaged by misinformation, said Akhtar.

“The simple science behind this is wearing a face mask keeps you from passing COVID to other people and most recently it’s shown that it also keeps each person wearing it from getting ill, so face masks do work,” Akhtar said.