A high-security laboratory in Louisiana recently leaked deadly bacteria, infecting four animals and apparently a federal investigator—but officials say there's no public health risk, USA Today reports. The probe began after two monkey-like animals at the Tulane National Primate Research Center were infected last year by a bacterium and had to be euthanized. Problem is, scientists were analyzing the Burkholderia pseudomallei bacterium in a lab that's billed as highly secure about a 5-minute drive away. "The fact that they can't identify how this release occurred is very concerning," says a biosafety expert. He notes that "human error," including poorly sterilized gloves, coats, and shoes, can cause such leaks. But the center's director, Andrew Lackner, says that "we're taking this extraordinarily seriously. It's very disturbing to us."
The investigation itself had issues. A USDA investigator fell ill 24 hours after visiting the site and tested positive for the bacteria, but may have been exposed during her international travels. And according to one study, the EPA ordered too few soil samples in the center's huge field cages, where some 4,000 animals live in an outdoor breeding colony. The 39 samples did, however, come back negative. If the bacteria escapes, ABC News reports that it can cause a disease called melioidosis that's common in Southeast Asia and Australia. It leads to various unpleasant symptoms and can be fatal; several countries have considered using it as a bioweapon. For now, research at the Louisiana lab is suspended but animal testing will go on as the investigation continues. (Read about two labs closed after a "dangerous gaffe.")