MILWAUKEE (AP) — Wisconsin health officials said Saturday that 331 tests for the coronavirus have come back positive in the last 24 hours, the largest single-day rise since the outbreak started. An additional four people have died.

The update raises the total number of positive cases to 5,687 and the statewide deaths to 266. State Department of Health Services data shows that 24 percent of infected people have been hospitalized.

There has been a significant spike in cases in Brown County in recent days, according to Wisconsin Public Radio. Health officials believe the increase is connected to positive tests at meatpacking facilities. As of Saturday afternoon, Brown County had 720 positive COVID-19 cases, 115 more than Friday.

State health leaders have said that cases are trending downward, though DHS charts continue to show a steady climb. The actual number of infections is thought to be far higher because many people have not been tested, and studies suggest people can be infected with the virus without feeling sick.

For most people, the coronavirus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. For some, especially older adults and people with existing health problems, it can cause more severe illness.