Eighty-four employees at the Atlanta-based U.S. Centers for Disease Control and Prevention are being monitored or given antibiotics after possibly being exposed to anthrax, the federal agency said Friday.

No one has shown symptoms of anthrax following the accidental exposure, CDC spokesman Benjamin Haynes said in an email to The Atlanta Journal-Constitution.

Haynes said 54 of the 84 employees being monitored for possible exposure had visited the CDC's Occupational Health Clinic; 52 had begun courses of antibiotics and 27 began taking an anthrax vaccine.

There is no risk of exposure to the deadly bacteria for other CDC staff, family members or the general public, according to a separate statement released by the agency. Anthrax is not contagious and cannot be caught like the cold or flu.

“Out of an abundance of caution, CDC is taking aggressive steps to protect the health of all involved, including protective courses of antibiotics for potentially exposed staff,” the agency stated.

Investigators found that the unintentional exposure occurred sometime between June 6 and June 13 — the day it was discovered. Staff took environmental samples and decontaminated the labs and hallways. The agency is investigating the incident and plans to review safety protocol with all employees.

The exposure happened after workers in a lab at the CDC’s Clifton campus failed to fully inactivate the bacteria while preparing samples for research. The samples were then sent to be used for experimentation to three other campus labs not equipped to handle live bacteria, according to the statement. Assuming the bacteria were inactive, lab workers handled the samples without wearing proper safety gear.

The problem was discovered when live colonies of bacteria were found on the original bacterial plates. Workers were using the samples to find new ways of detecting dangerous pathogens, the agency stated.

Anthrax is an infectious disease caused by bacteria known as Bacillus anthracis. The bacteria are found naturally in soil and commonly affect animals such as cattle, sheep and goats more than people, according to the National Institutes of Health. Symptoms of anthrax can include fever, chills, shortness of breath, confusion and body aches, among other conditions.

In 2001, anthrax sent through the mail killed five people and sickened 22 others, according to the institutes. While anthrax can be deadly, those infected can be easily treated with antibiotics if diagnosed early.