Deadly bacteria escape
A dangerous, often deadly, type of bacteria, Burkholderia pseudomallei, that lives in soil and water has been released from a high-security laboratory at the Tulane National Primate Research Centre in Louisiana. Officials say there is no risk to the public.
The cause of the release and the extent of the contamination remain unknown. The incident has raised concerns that bacteria from the lab may have contaminated the facility’s grounds and though initial, limited tests didn’t detect it, some officials are pressing behind the scenes for more action.
The safety breach at Tulane’s massive lab complex 35 miles north of New Orleans is the latest in a recent series of significant biosafety accidents at some of the most prestigious laboratories in the country where research is performed on bacteria and viruses that are classified as potential bioterror agents.
Tulane’s research, which has been halted by federal officials, was part of an effort to develop a vaccine against the bacteria. It was conducted mostly with rodents inside a secure biosafety level 3 laboratory with multiple layers of safety equipment that were supposed to ensure the pathogen couldn’t get out.
Yet at least 4 rhesus macaques, that were never used in the experiments and were kept in large outdoor cages in another part of the 500-acre facility, have been exposed to the bacteria, initial tests have found. 2 of the macaques became ill in Nov; both eventually had to be euthanised.
Meanwhile, a federal investigator, who became ill 24 hours after visiting the facility in Jan as part of the ongoing release investigation, has also tested positive for exposure to the bacteria – though it remains unclear whether her exposure may have occurred during international travel and not at the lab. The investigation so far indicates that the 4 macaques were exposed to the bacteria while being cared for in the complex’s veterinary hospital and tests of 39 soil and 13 water samples from the centre’s grounds have not detected the presence of the bacteria.
Yet studies reviewed by USA TODAY indicate too few samples were taken to detect what can be an elusive bacterium.
The Louisiana Governor’s Office of Homeland Security and Emergency Preparedness, which is leading the joint federal-state response, expressed concerns about “whether the organism has escaped the compound and whether livestock and domestic animals are at risk,” in a Feb. 20 letter from the state to the U.S. Environmental Protection Agency.
The primate centre is located near wetlands and a river, across the street from a school and close to a neighbourhood. The strain — known as Strain 1026b — was originally recovered from a rice farmer sickened in Thailand in 1993. Rice farming is a common way people are infected because the bacteria live in contaminated soil and water and can enter the body through cuts or sores on the skin.
The research will remain suspended until the lab breach investigation is completed and any problems are corrected, said the CDC, which jointly runs the Federal Select Agent Program with the USDA.
Burkholderia pseudomallei can cause a potentially serious disease in people and animals called melioidosis, that has a wide range of non-specific symptoms, such as fever, headache, loss of appetite, muscle and joint pain, and infections are often mistaken for other diseases such as pneumonia or tuberculosis. In Thailand, where the bacteria is endemic, the fatality rate for patients with melioidosis is up to 50%; in Australia it can be up to 20%, according to published studies.
Confirmed infections are relatively rare. There were 176 culture-confirmed cases of melioidosis in Australia’s north Queensland during the 10-year period 2000-2009, according to that country’s health department. By Feb. 25, ongoing tests had identified 2 additional animals from the outdoor breeding colony that had antibodies to Burkholderia pseudomallei, indicating they had been exposed even though they were not showing any signs of illness. Only 2 of the 4 exposed animals shared the same outdoor field cage, Lackner said.
But all 4 had been in the centre’s veterinary hospital around the same time, which has led CDC and Tulane to say the hospital is the leading suspect for where the animals were exposed to the bacteria. The deadly bacteria should never have been in the hospital — or anyplace else where the outdoor macaques could have been exposed to it.
Burkholderia pseudomallei should only have been inside the specific Tulane lab that was doing vaccine development research. That research was being conducted in a biosafety level 3 laboratory – the second highest containment level – with a wide range of high-tech safeguards, physical barriers and procedures that are supposed to ensure dangerous pathogens can’t escape.
The lab, as Tulane describes it, is essentially a “box-within-a-box within a box.” The research was being done in a completely contained lab under negative air pressure, inside Building 5. Air leaving the chamber passes through multiple HEPA filters before leaving the building. Access to the BSL-3 lab is strictly controlled. Everything that goes in can’t come out without being sterilized.
Research animals that go into the BSL-3 labs do not come out alive and never go to the hospital.
So how did the bacteria get out of the lab? Sloppy biosafety practices can result in pathogens being tracked out of labs. For now, Tulane is not planning to remove soil or fumigate the area. With no bacteria detected outdoors, the centre sees “growing evidence that makes it increasingly unlikely that Burkholderia pseudomallei has been in our outdoor breeding colony,” said Tulane spokesman Michael Strecker.
Testing of the animals in the outdoor breeding colony, however, will continue.
Filed under: GENERAL NEWS - International / National / Regional | Leave a comment »
Serbian Animals Voice (SAV) 