Rise in cases could be due to sports, school-mandated COVID-19 testing, McHenry County officials say

McHenry County is seeing more cases in young people, fewer cases in seniors; highest incident rate is among residents in their twenties

An increase in COVID-19 cases among McHenry County’s youth in recent weeks could be due to increased testing of students by school nurses now that in-person learning has resumed countywide, county Public Health Nursing Director Susan Karras said Monday.

The number of COVID-19 cases and hospitalizations in McHenry County have continued to increase this month despite more and more of the population being vaccinated, Karras said in a McHenry County Board of Health meeting Monday evening. But it is important to consider the context around these data points.

“There’s testing requirements that the school nurses are encouraging or having these students do and these families do, so I think we might be identifying more which could be driving up our positivity rate,” Karras said.

The increase in cases has been sharper in younger demographics like teenagers than the population overall and the highest rate of COVID-19 cases remains among the county’s 20- to 29-year-olds, she said.

The Illinois Department of Public Health also reported one outbreak among McHenry County schools, which was at Prairie Ridge High School in Crystal Lake that was related to nonsports activities. The outbreak involves five to 10 cases, according to state data, which was last updated Friday.

County residents 65 and older, on the other hand, are below the local historical average when it comes to their rate of COVID-19 cases, Karras said, which she attributed to the fact that 79% of the senior population in McHenry County has received at least one dose of a COVID-19 vaccine.

McHenry County is currently reporting a 7-day average of 28 positive cases of COVID-19 per 100,000 people and its positivity rate – the percentage of COVID-19 tests that return positive results – is 8.3%, which is above the state’s maximum threshold that can trigger the return of mitigation measures like reduced capacity in businesses.

The state tracks its metrics by health regions and McHenry County joins Lake County in forming Region 9, which is reporting a cumulative positivity rate of 4.3% as of Tuesday, according to data collected by the Illinois Department of Public Health. This means the region likely will not see the return of mitigation measures anytime soon.

The county’s hospitalizations for COVID-19-like illness also increased for the four out of the past ten days, Karras said. In general, hospital admissions have increased by 20% over the last couple of weeks.

Given this, McHenry County is now considered to have “substantial spread” of COVID-19, Karras said. She offered a few theories on what might be contributing to these increases.

Her first theory was that the COVID-19 testing required by school nurses could be revealing more cases of COVID-19 than were previously identified. The second theory was that the return of school sports and extracurricular activities could also be causing an increase in cases, she said.

A spike in cases also followed spring breaks, which occurred at different times from district to district, Karras said.

“We’re kind of contributing it to those types of things that are happening,” she said. “If that’s true, we hopefully will be flattening out once things kind of settle down.”

“The thing that we do worry about is, once these kids get out of school, we can’t track them anymore,” she added.

Without the testing mandated by schools, it will be very difficult for the McHenry County Department of Health to keep track of the infection rate among children and teenagers, Karras said.

Kelli Duncan

Kelli Duncan

Kelli Duncan is a reporter for the Northwest Herald covering county government as well as the communities of Huntley, Lake in the Hills, Marengo and Harvard. She has previously covered local politics, immigration and feature stories.