SPRINGFIELD, Ill. (AP) — The Illinois Department of Public Health is working to identify people who may have been in contact with a woman who has a rare and deadly form of hard-to-treat tuberculosis.

State health officials said Tuesday they are continuing to work with local health departments in northern Illinois and the Centers for Disease Control and Prevention.

The woman traveled from India to the United States in April. She arrived at Chicago’s O’Hare International Airport, and spent time in Missouri, Tennessee and Illinois before getting sick. She was admitted to an isolation unit at a suburban Chicago hospital and is now a patient at the National Institutes of Health Clinical Center in Bethesda, Maryland.

Health officials are tracing the woman’s contacts to determine who needs to be tested for TB infection.