Recent stories in the Boston Globe about three Boston University researchers who became infected last year with tularemia allege the contamination came from a lab at the University of Nebraska at Lincoln.
That’s not the case, said officials at UNL and UNMC, which comprise the University of Nebraska Center for Biosecurity.
The Centers for Disease Control and Prevention (CDC) has found no evidence of contamination with the virulent strain of tularemia in the samples emanating from the UNL laboratory.
“The University of Nebraska-Lincoln does not work with the virulent strain of the tularemia bacteria in its labs; researchers work only with the vaccine strain, known not to cause disease in humans,” said Prem Paul, Ph.D., vice chancellor for research at UNL.
A UNL researcher sent vials of tularemia bacteria (safe vaccine strain) to Boston University in April 2004. The bacteria was cultured at UNL from a strain, which came from the FDA and is publicly available and known not to cause disease in humans.
Many months after the UNL vials were shipped to Boston, and the Boston University lab workers became ill, the vials in Boston were tested and found to have a virulent strain.
Original UNL vials in Lincoln have been tested by the CDC and were found to be free of virulent strain.
Tularemia, also known as “rabbit fever,” is caused by a natural occurring bacterium found typically in wild animals, especially rodents, rabbits and hares, and occasionally in pets such as cats, according to the CDC. People come in contact with F. tularensis in a variety of ways — the bite of an infected insect, usually a tick or deerfly; handling infected animal carcasses; eating or drinking contaminated food or water; or breathing the bacteria. About 200 cases of tularemia, including three to four in Nebraska, are diagnosed annually.
UNMC has a BL-3 (high containment biosafety) laboratory, a world-class repository for strains of tularensis, and has federally-funded researchers working to analyze the way that tularensis becomes infectious. UNMC has never had any infections among its researchers or laboratory staff.
“Handling pathological specimens of all kinds is something that is carried out routinely and safely by all academic medical centers across the nation. The fact that we have people on campus who are experts in tularemia assures the safety of our labs. We are disappointed that BU has chosen to follow this path and hope we can help them improve the safety of their operation,” said Thomas Rosenquist, Ph.D., vice chancellor for research at UNMC.
While there is no evidence the contamination originated in Nebraska, Boston University has a history of tularemia infections among laboratory workers. In 2001, for example, a laboratory worker became infected and died from tularemia, as published in the Journal of Clinical Microbiology (June 2002, Vol. 40, pp. 2278-2281.) Several lab workers at Boston University were hospitalized with tularemia infections in 2004.
Steven Hinrichs, M.D., Ph.D., director of the University of Nebraska Center for Biosecurity, plans to request a sample of the material from Boston University and offer the research services of the University of Nebraska to help Boston University determine the source of the more virulent strain of tularemia since Nebraska has the technology to track the source.
In detailed discussions with CDC and the Nebraska Health Department, UNL has been
assured that it is in compliance with all reporting and handling procedures, Dr. Paul said.