After a series of anthrax attacks in 2001, the US tightened regulations on research using many pathogens, including Ebola, pictured in a transmission electron micrograph.
In the first study of its kind, the US Centers for Disease Control and Prevention (CDC) unveiled statistics on problems related to the handling of hazardous biological agents, such as Ebola, SARS and anthrax, at hundreds of academic and government research centres.
Laboratories that work with biological select agents and toxins - materials highly regulated for their potential to cause human disease - reported that pathogens were inadvertently released 639 times between 2004 and 2010.
During the same period, laboratories also reported losing 88 samples, although bookkeeping errors accounted for all but one. The remaining lost sample was accidentally destroyed by a commercial courier.
The study, published in the current issue of Applied Biosafety
, says that no occurrences of theft were reported.
Over the 7-year period, laboratories reported 11 lab-acquired infections, at an average annual rate of 1.6 per 10,000 authorized workers. Ten of the infections were traced to bacterial sources, and one was due to fungal exposure. None of the infections were fatal, and none were reported to have spread to other people.
The infections could not be linked to obvious breaches in personal protection, such as torn gloves or cuts from sharp objects. Instead, the authors suggest that workers probably acquired infections from the release of aerosols containing the harmful agents. The team says that it is continuing to analyse reports of pathogen releases and lab-acquired infections to identify possible gaps in safety procedures.
"The bottom line is we have a lot of success to report, if you consider that it's a program that regulates over 300 [laboratories] across the US," says report co-author Robbin Weyant, director of the CDC's division of select agents and toxins.
Current regulations date back to counter-terrorism legislation passed in the wake of the 2001 anthrax attacks
in the United States. A Federal Bureau of Investigation inquiry concluded that microbiologist Bruce Ivins, who worked at a government biodefence laboratory, was responsible for mailing anthrax spores that killed five people and sickened 17 others.
In recent years, government scrutiny and restriction of research on infectious agents has escalated to the point of slowing scientific progress, says Michael Buchmeier, deputy director of the Pacific Southwest Center for Biodefense and Emerging Infectious Diseases at the University of California, Irvine. He says the report suggests that theft and accidental loss of dangerous pathogens from research laboratories are not as widespread as some people have predicted.