An Army biodefense researcher at Fort Detrick was exposed to anthrax last week after a laboratory spill, and some spores escaped into an adjoining office and corridor, officials at the U.S. Army Medical Research Institute of Infectious Diseases in Frederick said yesterday.
The researcher, whose nasal passages were found to contain anthrax spores, had previously been vaccinated against anthrax and is not in danger, said Fort Detrick spokesman Chuck Dasey. He said that worker and another who was present when the spill was discovered are taking antibiotics as a precaution.
After a series of briefings yesterday, 18 workers who have not been vaccinated against anthrax reported that they had recently been in an office and corridor where anthrax spores were found, according to one official who asked not to be named. They were offered antibiotics and nasal swab tests, the results of which were not available last night.
About 100 employees who work in or near areas where spores were found were relocated yesterday to uncontaminated areas, Dasey said. He said extensive sampling is being conducted to make certain the contamination is not more widespread.
No one has complained of any symptoms of illness "suggestive of anthrax exposure," he said. He said there is no reason to expect any danger to the surrounding communities in Frederick.
While USAMRIID scientists have assisted in the investigation of the anthrax letters mailed last fall, the spilled anthrax was part of unrelated research, Dasey said. There was no indication the anthrax contamination in and outside the lab was deliberate, officials said.
The contamination inside Building 1425, the major laboratory facility at the military's premier biodefense research center, is disturbing because so many precautions are taken to keep dangerous organisms contained inside the so-called "hot" zones.
One veteran researcher who has worked at USAMRIID for more than two decades said he could not recall another such leak. "What we're still scratching our heads about is how it got out there," he said.
The anthrax work was being conducted in an "enhanced Biosafety Level 3" area. Workers in that area wear surgical suits, gloves and optional masks rather than the full-scale biohazard suits used in Biosafety Level 4, which is reserved for the most dangerous pathogens, such as Ebola.
On April 8, the two lab workers noticed a flask with a loose stopper, which had permitted a small amount of the liquid anthrax mixture inside to spill. They reported the incident and were given the nasal swab tests, which tested positive for one worker and negative for the other.
On Monday, officials decided to test for anthrax spores in areas that adjoin the laboratory. Small numbers of spores were found in a changing room and corridor, and a single spore was found on a desktop in an office.
It is not clear whether all the spores found outside the lab came from the flask with the loose stopper, officials said. Sophisticated genetic analysis is planned, to see if the spores found in different locations match the sample in the flask, they said.
Dasey said the 600 employees briefed on the findings in a series of meetings, starting at 10 a.m. yesterday, remained calm.
"The people who work at USAMRIID are scientifically oriented and understand the risk to them from this incident is quite low," he said. "These types of things happen in laboratory settings."
Last month, a Texas laboratory worker who had handled vials containing anthrax samples without gloves got a skin anthrax infection on his face, the Centers for Disease Control and Prevention in Atlanta reported. None of the 40 workers in that lab were vaccinated against anthrax.
During the old offensive biological weapons program based at Fort Detrick from 1943 to 1969, a microbiologist and an electrician died of anthrax contracted accidentally in the laboratories.