A researcher at the Tulane National Primate Research Center near New Orleans may have been exposed to a potentially lethal bioterror bacteria.
The Centers for Disease Control and Prevention confirmed the possible exposure to CBS News, but it remains unclear how the bacteria, burkholderia pseudomallei, could have been released from the high-security lab. The CDC also confirmed that several rhesus monkeys at the facility also came in contact with the bacteria, even though the animals were housed in a cages nearly a mile away. Researchers at the lab are using the bacteria on mice with the hopes of developing a vaccine against Whitmore disease, an illness that can occur from transmission of the bacteria.
"The amount of antibodies found in the employee was just at the threshold for a verified positive result," Jason McDonald, a spokesperson for the CDC, told CBS News in a statement. "This level is sometimes found in members of the public, even among those who have no history or knowledge of actual exposure. The employee is well and showing no symptoms of illness. Additional tests will be needed to confirm any exposure and, if confirmed, determine whether it likely occurred at the TNPRC or elsewhere. CDC estimates results could be known by early next week."
In early November, two monkeys at the research facility become ill and were found to have Whitmore disease, which is caused by exposure to burkholderia pseudomallei. Both animals failed to recover with treatment and were eventually euthanized. Tulane alerted the CDC of the situation in December. The bacteria strain that killed these monkeys matched the one used for experimentation in the lab. Since then, 67 monkeys have been tested and an additional six monkeys were found to be positive for burkholderia pseudomallei antibodies, including one confirmed last night.
But a positive blood test doesn't necessarily indicate that a monkey will get sick, says McDonald. A series of four tests will be conducted over a period of six weeks, and if antibody levels stay consistent this indicates the exposure did not recently occur. The CDC has requested another blood sample from the monkey because the antibody level was also at the threshold and "additional testing would give more clarity."
A U.S. Department of Agriculture inspector involved in the investigation become ill on Feb. 7 after leaving the primate center. She was found to have bacteria antibodies that remained at a consistent level, indicating she had not recently been exposed. It was later learned that she had a history of international travel in areas where the bacteria is common.
"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," said McDonald.
Through the investigation, health officials hope to pinpoint where transmission occurred. They suspect that the animals and employee may have come in contact with the bacteria at the facility's veterinary clinic, where all of them were at some point during the time period of likely transmission. At the request of the USDA, Tulane will begin testing other wildlife and feral cats on the facility's property, according to USA Today.
Burkholderia pseudomalleim is typically found in water and soil and can be contracted through direct contact with contaminated particles or water. The bacteria causes Whitmore disease, which infects the lungs and causes abscesses. It can lead to a secondary infection such as bronchitis and pneumonia. Whitmore disease also impacts the blood, kidneys, heart, among other vital organs.
Whitmore disease is a risk in Southeast Asia and Australia, and is very rarely transmitted from person to person.