Federal and state health officials are searching for individuals in at least three states who may have come in close contact with a woman from India now being treated for extensively drug-resistant tuberculosis (XDR TB) at the National Institutes of Health Clinical Center in Bethesda, Maryland.

XDR TB, a rare form of the disease, is resistant to isoniazid and rifampin plus any fluoroquinolone and at least one of three injectable second-line treatments (amikacin, kanamycin, and capreomycin). There have been 63 reported cases of XDR TB in the United States between 1993 and 2011.

The woman entered the United States in early April through Chicago O’Hare International Airport, spent time in Tennessee and Missouri, and then visited relatives in McHenry County, which borders Chicago.