CHICAGO (CBS) — The head of Chicago’s Department of Public Health added Hawaii, Nebraska and North Carolina to the city’s travel quarantine list.

Doctor Allison Arwady said Indiana is getting very close and could be added to the list as early as next week.

“We are really seeing some localized concerns in Indiana, more than we are seeing major widespread COVID across the whole state. And particularly, they’re having problems as many other Midwest states are related to universities,” Arwady said. “So you’ll see up north there in Indiana, where South Bend is, that’s where Notre Dame is and adding hundreds and hundreds and hundreds of cases in a single week has really turned that county to a high risk county.”

She said another college town in Indiana is reporting high case numbers.

“About halfway down in the state, where Muncie is that’s Ball State University, which similarly has had a few hundred cases and really driven that rate up. We made a decision not to put Indiana on the list this week,” Arwady said. “I want to let Chicagoans know that we have concerns about Indiana, and particularly would encourage you not to travel to college and university towns in Indiana. If we don’t see improvement across the state, we will then add them next Tuesday. So we’re keeping an eye on it.”

Arwady said in Chicago, there’s cause for concern as COVID-19 spread continues to spread within gatherings of friends and family.

“We are regularly seeing where people are getting together with friends and with families, and with neighbors and with extended families, this is not in a regulated setting,” Arwady said. “This is at somebody’s home. But where people are letting down their guard, not wearing masks, perhaps not always social distancing, we sometimes can see clusters like this.”

Last week, South Dakota was put on Chicago’s travel quarantine list, according to the city’s department of health.

In August, Puerto Rico joined the quarantine list which now includes Alabama, Arkansas, California, Florida, Georgia, Hawaii, Idaho, Iowa, Kansas, Louisiana, Mississippi, Missouri, Nebraska, Nevada, North Dakota, North Carolina, Oklahoma, South Carolina, South Dakota, Tennessee and Texas.

Chicago’s quarantine mandate requires anyone arriving in the city from states considered to be COVID-19 hot spots to self-isolate for a minimum of 14 days when they arrive in the city, including visitors to Chicago, and residents who are returning from travel to one of the states.

The list of states included in the order is updated weekly to include states with more than 15 new COVID-19 cases per 100,000 resident population per day, over a 7-day rolling average.

On Tuesday, the state of Illinois reported 1,492 new coronavirus cases, down from Monday’s new case count at 1,668.