Heading into the Christmas holiday, flu activity remained at “high” levels in McHenry County.

The McHenry County Department of Health’s weekly respiratory illness surveillance report, which covers the week of Dec. 7 through Dec. 13, said flu had reached “high” activity.

Other respiratory illnesses, including COVID-19 and respiratory syncytial virus, remained at “moderate” levels, the same as the previous week.

While the levels stayed the same, flu emergency department visits were up 23.3% from the previous week, “with most visits among those aged 5 to 24 years,” according to the report. Inpatient admissions for flu were up 60%. There also was a flu cluster in a long-term care facility.

Despite “moderate” activity, emergency room visits for COVID-19 were up 120% over the previous week. Most visits were among those ages 25 to 49 or 65 and older. Inpatient admissions were up 133.3% over the last week, according to the report.

There also were two COVID-19 clusters in long-term care facilities, according to the report.

RSV was “moderate” in terms of activity, but emergency room visits were stable, “with most visits among those aged 0 to 4 years,” according to the report. Inpatient visits for RSV increased 100% from the previous week, the health department said. There was one ICU admission related to RSV.

Ahead of the Thanksgiving holiday, the health department posted that it had been seeing an uptick in respiratory illness. The department encouraged people to stay home from gatherings if they are sick, and noted that vaccination offers the best protection against respiratory illness.

The full report is available online: mchenrycountyil.gov/home/showpublisheddocument/120725/639015865777000000.