Gwinnett Medical Center has sent 133 letters to former patients urging them to get tested for tuberculosis.

The hospital's chief medical officer, Dr. Alan Bier, says an employee came down with an active case of TB the middle of May and they're issuing the letter to those patients who came in direct contact with that employee from February 1 to May 10.

Employees at the hospital are tested for TB annually, and the employee who contracted it tested negative in June 2012.

No information is being released about the employee or in which department the person worked.  But none of the other employees tested at the hospital have tested positive for the disease.

Bier says if anyone should test positive on the skin test, they shouldn't be fearful.

"It's important to stress that it does not mean that they have active TB and it does not mean they're infectious," says Bier.  "So, any of these patients who have a positive skin test, they shouldn't be overly concerned about their family or other close contacts."

The Department of Epidemiology of the Gwinnett County Health Department is currently investigating how that employee contracted the disease, although the hospital admits it has treated patients with TB in the past.

Bier says those former patients who received a letter can have a free skin test at any of the Gwinnett Health Department's locations.  Or they can have it done at their doctor's office, but the results have to be reported to the Department of Health.

While the number of TB cases has steadily declined in Georgia over the past two decades, the State Department of Health reports Georgia ranks 11th in the number of cases in the country.