HAGERSTOWN, Md. (AP) -- At least 11 workers at U.S. biological laboratories were infected with dangerous pathogens from 2004 to 2010, the federal Centers for Disease Control and Prevention said Tuesday in a report on security measures stemming from the deadly 2001 anthrax attacks.
None of the infected workers died. The Atlanta-based agency said the infection rate of 1.6 per 10,000 workers was far lower than the rate of general occupational illnesses in scientific research and development facilities.
"If you look at the report as a whole, it's a success story," said report co-author Robbin S. Weyant, who oversees CDC regulation of about 70 "select agents and toxins" deemed a severe threat to human, animal or plant health.
"We have about 10,000 people a year working in these laboratories. To have such a small number of confirmed infections over nearly a decade, I think, is quite good," Weyant told The Associated Press in a telephone interview.
The report was published in the January issue of Applied Biosafety. It did not identify the workers or their laboratories by name.
Congress authorized the biolab reporting requirements after five people were killed and 17 sickened by anthrax mailings in 2001 that the FBI attributed to a civilian researcher at an Army lab at Fort Detrick in Frederick, Md. Labs must regularly inventory certain pathogens and immediately report any theft, loss or release of those agents.
The CDC report said there were no thefts among the 727 reports it analyzed.
Of 88 reports of lost pathogens, the CDC reconciled 87 to bookkeeping errors. The other incident involved a lost shipment of the fungus responsible for Valley fever in 2007. An FBI-led investigation concluded the package was damaged by a commercial courier, discarded as refuse and incinerated, the CDC said. Valley fever causes chest pain, headache and ankle and feet swelling in humans. It's rarely fatal.
The infections among lab workers resulted from some of the 639 reported releases of pathogens. The infections were from bacteria that cause brucellosis, a livestock disease that can cause flu-like symptoms in humans; tularemia, an infection common in wild rodents that can cause fever, headache and muscle pain in humans; and Valley fever fungus. There were no confirmed cases of infections transmitted to another person.
None of the 11 infections was linked to a recognizable event such as a cut or tear in protective clothing. Rather, they presumably resulted from aerosol releases of pathogens, the CDC said. The agency noted it's usually difficult to trace lab-worker infections to a single, identifiable event.
Gigi Gronvall, senior associate at the University of Pittsburgh Medical Center's Center for Biosecurity in Baltimore, said diagnostic lab workers often don't know what pathogen they're working with until they've analyzed it. That alone can put them at risk.
"Aerosols are generated by stirring, or opening up a plate," she said. "In the course of doing your scientific work, some of it comes into the air."
Seven of the 11 infections occurred in relatively low security labs, such as hospital diagnostic labs, with fewer safeguards than high-security research labs.
"We're hoping that this data will lead us toward some additional safety recommendations in that environment that will reduce the potential for exposure" in those labs, Weyant said.
The target of the FBI's anthrax investigation, Bruce Ivins, killed himself with an overdose of Tylenol and valium in 2008 as investigators closed in. His attorney has maintained Ivins' innocence though Justice Department prosecutors have said they had more than enough evidence to convict him at trial.