The accidental release of dangerous bacteria at a Louisiana research center probably occurred because workers were lax about how they wore protective garments in the lab where the germ was kept, federal officials said Friday.
However, officials with the Centers for Disease Control and Prevention say the release is not a danger to the general public.
Federal officials believe that in November, the bacteria spread from a lab to other areas of the Tulane National Primate Research Center in Covington. Eight monkeys kept outside the lab were later found to be infected.
A two-month investigation found some lab workers were lax about tying closed and taking off outer garments. When they finished their work in the lab, Tulane workers commonly kept on the scrubs and shoes they wore underneath those outer garments, CDC investigators found.
Officials believe the bacteria hitched a ride on those scrubs and shoes when workers walked to other areas. "That's what we think is the most likely cause" of the release, said the CDC's Robbin Weyant.
CDC officials presented the findings of their investigation to Louisiana officials during a meeting Friday morning.
A Tulane spokesman could not immediately be reached for comment.
The germ, called Burkholderia pseudomallei, is found in contaminated water and soil in tropical climates - particularly Southeast Asia and northern Australia. It is spread to humans and animals through direct contact with the contaminated source and is not believe to spread from person to person.
Most people infected with these bacteria do not get sick. But some come down with melioidosis - also known as Whitmore's disease - which can sicken humans or animals and in some cases prove fatal.
Burkholderia pseudomallei is considered a "select agent" - a germ or toxin that could pose a severe threat to the public health. The Tulane research center has been working with select agents since about 2008, CDC officials said.
The Tulane lab staff was working with the germ to develop a vaccine, in experiments involving mice.
The CDC works closely with the U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) to monitor research facilities that use select agents in experiments with animals.
An APHIS investigator was found to have antibodies to the bacteria, but officials have concluded that likely came from exposure to the germ during a past overseas trip. A Tulane worker this week was found to have antibodies during an initial test. But additional tests will be needed to confirm that the person has been infected with Burkholderia pseudomallei, and that it came from a recent exposure at the lab, CDC spokesman Jason McDonald said.