A University of Chicago geneticist studying the genetics of Yersinia pestis, the bacterium that causes plague, may have died from exposure to a weakened strain he worked with in the laboratory.

Wayson stain of Yersinia pestis Image: Wikimedia commons, US Center for Disease Control

Malcolm J. Casadaban died on September 13. Autopsy results on Friday (September 18) revealed the presence of the bacteria in the researcher's blood, and suggested no other possible cause of death.

The strain Casadaban worked with lacks the bacteria's harmful components and is therefore not believed to be dangerous to healthy adults. It has been approved by the Centers for Disease Control and Prevention (CDC) for routine laboratory studies, and handling it does not require any special safety procedures.

It is possible, however, that this particular strain was different than the CDC-approved strain or that Casadaban had underlying genetic or health conditions that made him more susceptible to infection, virologist and chief of pediatric infections at the University of Chicago Medical Center Kenneth Alexander told the Chicago Sun-Times.

"This death is a tragic loss to our community," James Madara, Dean of the Biological Sciences Division and Pritzker School of Medicine and CEO of the Medical Center, said in a statement. "We are all saddened to lose a valued colleague."

The city and state public health departments and the CDC are investigating the case. Although no one else in contact with the strain, or with Casadaban himself, has reported any symptoms, anyone who might have been exposed is being offered antibiotics as a precaution.


Related stories:

To Fight Plague, Look to Russia's Past
[10th October 2005]

Plague Genome: The Evolution Of a Pathogen
[29th October 2001]

Plague genome
[4th October 2001]