Concerns arose at the center in Covington, Louisiana, after two rhesus macaques became ill in late November with melioidosis, a disease caused by the tropical bacterium Burkholderia pseudomallei. In January, the U.S. Centers for Disease Control and Prevention (CDC) and Department of Agriculture investigators traced the strain infecting the primates to a vaccine research lab working with mice. Last month, as the investigation continued, CDC suspended the primate center’s 10 or so research projects involving B. pseudomallei and other select agents (a list of dangerous bacteria, viruses, and toxins that are tightly regulated). Meanwhile, a report in USA Today suggested the bacterium might have contaminated the center’s soil or water.

In addition, workers “frequently entered the select agent lab without appropriate protective clothing,” the release says. No center staff has shown signs of illness. On 12 March, however, Tulane announced that blood tests have found that one worker has low levels of antibodies to the bacterium, suggesting possible exposure at the center, according to ABC News.