The U.S. Centers for Disease Control and Prevention says approximately 75 staff working in government laboratories in Atlanta may have been exposed to live anthrax and are being monitored and evaluated for infection. The exposure is suspected to have occurred when CDC researchers failed to follow appropriate protocol while transferring the bacteria from a high-security laboratory in Atlanta to a lower security CDC lab, which wasn't equipped to handle live anthrax.
"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 said in a statement. "Based on most of the potential exposure scenarios, the risk of infection is very low."
The CDC's report says scientists at the Roybal campus biosafety level 3 labs were preparing Bacillus anthracis -- the bacteria that causes anthrax infection -- for research in a different lab. They did not use the appropriate protocol to inactivate the bacteria, which is necessary for safe transfer. The samples were then moved and used in three CDC Roybal campus laboratories. The transfer is believed to have occurred between June 6 and June 13.
The possible exposure was discovered when researchers gathered plates for disposal and discovered they were populated with live bacteria.
"Workers, believing the samples were inactivated, were not wearing adequate personal protective equipment while handling the material," the agency explained in the statement. "Environmental sampling was done, lab and hallway areas were decontaminated and laboratories will be re-opened when safe to operate."
The CDC believes that other scientists at the facility, families of employees and the general public are not at risk of anthrax infection and don't need to take medical action.
The agency says they will be reviewing safety protocols with all employees and "disciplinary actions will be taken as necessary."
"CDC's guiding principles for laboratory work are to ensure the safety of all staff and the community and be as transparent as possible about our work as we conduct high-quality scientific research to protect people in this country and around the world," the agency said.
Bacillus anthracis is found naturally in soil. Domestic and wild animals such as cattle, sheep, goats, antelope and deer can become infected after breathing or ingesting spores through soil, water and plants.
Though rare, anthrax infections can occur in humans when spores enter the body through inhalation, food or water consumption. Once spores are activated they release toxins that can have a systemic impact on the body.
Symptoms of anthrax skin infection include blisters and itchy sores. Nausea, vomiting, abdominal pain, headache, appetite loss if the bacteria enters the gastrointestinal system. Anthrax infection in the lungs may present with chest pain, flu-like symptoms, painful swallowing. Later stages may include high fever and meningitis, which is inflammation and infection in the brain.
If caught early the infection is highly treatable with antibiotics, such as ciprofloxacin or doxycycline.