A suburban Cook County resident is this year’s first confirmed case of measles in Illinois, state officials said.

The resident became ill in mid-January and tested positive for measles, the Illinois Department of Public Health said. His or her vaccination status for measles was unknown, which a Cook County Department of Public Health said likely means that vaccination wasn’t done.

CCDPH spokesperson Amy Poore-Terrell said the resident was an adult living in northern suburban Cook County, but declined to give any other information to protect the person’s identity.

Officials said those who may have been exposed include:

  • Patients of and visitors to the emergency room of Northwest Community Hospital, 800 W. Central Rd., Arlington Heights, from 7 p.m. to 12:30 a.m. on Jan. 14, and from 4 p.m. to 10:30 p.m. on Jan. 17.
  • Customers of the Supermercado Guzman, 1611 N. Baldwin Rd., Palatine, from 5:30 p.m. to 8 p.m. on both Jan. 12 and Jan. 13.
  • Patients of and visitors to the Vista Clinic, 1585 N. Rand Rd., Palatine, from 12:30 p.m. to 4 p.m. on Jan. 16.

Measles is a highly contagious respiratory disease caused by a virus. It spreads through the air through coughing and sneezing, the Centers for Disease Control and Prevention says.

A person who was potentially exposed and is experiencing symptoms of a fever of 101 degrees or higher, cough, runny nose and red eyes without rash, should call the Cook County Department of Public Health at 847-818-4020 and their health care provider, state officials said. These individuals should not go to their doctor’s office or the emergency room because they could infect others around them. Rather, they should stay home.

A Northwest Community Hospital official declined to say any more about the person who was confirmed to have measles on Saturday, except to say that he or she was no longer at the hospital. Alice Brown, spokesperson for Northwest Community Hospital, added that the hospital had made phone calls and sent notice via regular mail, starting today, to alert those who were in the emergency room at the same time as the person confirmed to have measles.

A person who answered the phone at Supermercado Guzman who identified himself as the manager said he had no information about the person who got sick, and was not aware of anyone else who got sick as a result of exposure to that person.

“This case in Illinois is a reminder of the importance of immunizations,” Illinois Department of Public Health director Nirav Shah said in a statement. ”With only 10 cases reported in Illinois over the past five years, many parents may not have experienced the severe illness that can be caused by measles. Immunizations are vital to protect not only each child, but one community as a whole.”

The CDC says there was a record number of measles cases during 2014, with 644 cases from 27 states reported to CDC’s National Center for Immunization and Respiratory Diseases (NCIRD). That’s the largest number of cases since measles elimination was documented in the U.S. in 2000 and more than the past four years combined.

The majority of the people who got measles were unvaccinated, CDC said.

Measles made national headlines when there was a recent outbreak in Disneyland in California. So far, U.S. health officials say there have been at least 87 cases reported so far, the Los Angeles Times reported. Poore-Terrell said there does not appear to be a connection with the outbreak in California and the Illinois measles case, but they are still investigating.