After announcing more than 1,500 new known coronavirus cases and 19 confirmed deaths, state health officials said Friday four counties are at a “warning level” for COVID-19 because of outbreaks of the virus.

A total of 1,532 new known COVID-19 cases were disclosed Friday by the Illinois Department of Public Health, with all new confirmed deaths from Cook, DuPage or Winnebago counties. The new numbers came a day after officials announced the highest daily total of new cases since Memorial Day, 1,624 new infections. Officials also reported 44,330 new tests in the preceding 24 hours. The seven-day statewide positivity rate was 3.4%.

In Cook County, a woman in her 60s, three women in their 70s, a man in his 70s, four women in their 80s and four women in their 90s died. The DuPage County deaths were three women in their 90s and one woman more than 100 years old. One woman in her 60s and another woman in her 90s died in Winnebago County.

The state reported 1,471 people in Illinois hospitalized as of Thursday night with COVID-19. Hospitals saw 325 of these patients in intensive care units, with 58% of ICU beds in use, and 115 patients on ventilators, with 20% of ventilators in use. Patients with reported cases range from under 1-year-old to more than 100 years old.

LaSalle County, just outside the Chicago area, and Peoria County, as well as Adams County, with a county seat Quincy, in western Illinois, and rural Randolph County in southwest Illinois were put on a “warning level” Friday. The four counties all saw outbreaks of coronavirus recently related to various risk factors, according to state officials.

Counties at warning levels are those identified as having two or more risk factors for increased COVID-19 cases. The warnings don’t necessarily change a region’s lockdown level, but are meant to be a guide for local officials and residents regarding “personal and family gatherings, as well as what activities they choose to do,” according to a state news release.

LaSalle County had a jump in coronavirus cases because of family and social gatherings, young people going to bars and inconsistent mask requirements, according to officials. The county also saw more cases reported by people younger than 29. Peoria County is also had an increase in people younger than 29 getting COVID-19, and outbreaks related to gatherings and travel to Florida, Iowa, Texas and Wisconsin.

Adams County saw outbreaks related to residents traveling to Missouri and Iowa, states identified as COVID-19 hot spots. Outbreaks also happened following large social events, health care exposure, and travel to worship and youth sports, according to state officials.

Randolph County saw cases related to bars not complying with mask and social distancing guidelines, crowded places and parties among households — including one party with more than 200 people, officials said.

Counties with 50 or more new cases per 100,000 people or death numbers increasing more than 20% for two weeks in a row are at risk, according to the state. The agency said seven-day test positivity rates above 8% can contribute to warnings.

Counties at risk also can include those with: more than 80% if intensive-care beds occupied; 20% weekly increases in COVID-19-related emergency room visits; and 20% increases in weekly coronavirus hospitalizations.