Worker at Tulane possibly exposed to bioterror bacteria

Alison Young | USA TODAY

New tests indicate a worker at the Tulane National Primate Research Center near New Orleans has been exposed to the dangerous bioterror bacteria that was somehow released from a high-security lab on the property, a federal official said Wednesday night.

Blood tests conducted by the Centers for Disease Control and Prevention indicate the employee of the primate center's veterinary clinic has a "possible current or prior exposure" to the bacterium Burkholderia pseudomallei, agency spokesman Jason McDonald said. The worker shows no signs of illness and additional testing is needed to confirm the exposure, he said.

It is the first indication that a worker at the huge research complex has been exposed to the bacteria, which can cause potentially fatal disease. Tests of other employees have been negative. McDonald said ongoing tests also identified an additional monkey that has antibodies to the bacteria, bringing to eight the number of monkeys that tests indicate have been exposed or sickened at the complex.

None of the exposed monkeys was being used in experiments and they never should have come into contact with the bacteria, which is tightly regulated as a research material because of its potential for use in a bioweapon.

Tulane officials did not immediately provide any comment.

The primate center became the focus of federal and state investigations after tests in December showed two rhesus macaque monkeys — which were not part of any experiments — were sickened by a strain of bioterror bacteria being studied in the biosafety level 3 lab elsewhere on the 500-acre campus in Covington, La. Both of these initial monkeys, which became so ill they eventually were euthanized, were housed in large outdoor cages in a breeding colony of about 5,000 animals before being taken to the veterinary hospital for treatment.

In recent weeks, additional tests have identified more monkeys that were exposed to the bacteria, possibly during treatment in the hospital.

The lab incident is of particular concern because Burkholderia pseudomallei lives and grows in soil and water. It is primarily found in Southeast Asia and northern Australia. It is not found in the United States, the CDC says. Louisiana state officials have expressed concern that the lab accident may have resulted in the environment around the primate center becoming contaminated with the bacteria. They formally asked the U.S. Environmental Protection Agency for help testing soil for contamination.

Tulane officials have said they do not believe the bacteria got out of their buildings and they point to initial, limited soil and water tests that have not detected it. USA TODAY previously reported that studies indicate that too few tests were done to find the potentially elusive bacteria if they are present.

Tulane this week said it is going to begin testing wildlife and feral cats on its property for possible exposure, at the request of the U.S. Department of Agriculture and state officials.

"The CDC has found no evidence to date to suggest Burkholderia pseudomallei was released into the surrounding environment and therefore it's unlikely there is any threat to the general population," McDonald said Wednesday.

Despite weeks of investigation by the CDC and numerous other federal and state agencies, it remains unknown how the bacteria got out of one of the primate center's biosafety level 3 labs. Federal officials returned to the primate center this week to continue investigating.

The CDC and Tulane have said they suspect that the monkeys, which lived in the outdoor breeding colony and away from the lab, were exposed to the bacteria inside the center's veterinary hospital. All of the animals that have tested positive for the bacteria were treated in the hospital sometime between last fall and Feb. 2, when the clinic was decontaminated.

It is not known how the bacteria got into the hospital, which is in a different building about a five-minute walk from where the lab is located.

The veterinary clinic worker with preliminary tests indicating exposure, is well and not showing any signs of illness, McDonald said. "The amount of antibodies found in the employee was just at the threshold for a verified positive result," he said in an e-mail. "This level is sometimes found in members of the public, even among those who have no history or knowledge of actual exposure."

Additional tests are needed to confirm the employee's exposure and, if confirmed, to determine whether it occurred at the primate center. The results of those additional tests could be available by early next week, McDonald said.

A U.S. Department of Agriculture inspector, who was part of the original federal team investigating the bacteria release, became ill after leaving the primate center. While tests showed she had antibodies to the bacteria, CDC has said that further testing indicates that the exposure is not new and didn't occur at Tulane. The investigator has a history of international travel to an unidentified country where the bacteria is endemic, the agency has said.

The bacteria can cause a potentially serious disease called melioidosis in people and animals. It has a wide range of symptoms, from fever to localized skin infections to deadly pneumonias. Contact with contaminated soil or water is the main route of exposure. Most of those exposed will not show any symptoms. But the bacteria can hide for years in the body, CDC officials said. In countries where the bacterium is endemic, the fatality rate for patients with melioidosis can be up to 50%. And even with the best medical care, serious infections can be difficult to treat and involve long courses of antibiotics, CDC officials said.

The bacterium has been studied in other countries as a possible bioweapon, and Tulane said its research involved work to develop a potential vaccine.

As a result of the release of the bacteria, federal regulators ordered Tulane's primate center to halt all research involving select agents until the cause of the accident was identified and corrections were made. Andrew Lackner, primate center director, has said about 10 projects involving a variety of select agents were impacted by the order.

News of the Tulane worker's initial test result prompted one local official to call for more action.

"We are awaiting the confirmation test results to know exactly how this could have happened. However, I am calling on our federal partners to be more aggressive and commit more resources, because we must move up the timeline on the investigation," said Pat Brister, president of St. Tammany Parish, where the primate center is located. "We also are calling on Tulane and CDC to present the facts to the people of this parish in a public meeting."

Deadly bacteria released at Louisiana high-security lab USA TODAY​'s Shannon Rae Green interviews investigative reporter Alison Young about the latest incident in a series of security lapses at bio labs across the country.

For full coverage of the Tulane bacteria release incident and other laboratory safety issues nationwide, go to: biolabs.usatoday.com

Follow USA TODAY investigative reporter Alison Young on Twitter @alisonannyoung