WASHINGTON -- A high-security biodefense laboratory in Texas has lost track of a lethal hemorrhagic fever virus sample in an incident said to underscore recent government warnings about how the United States oversees the deadly disease agents it holds for study.
Experts and researchers at other institutions have generally chalked up the Guanarito virus sample's disappearance to an clerical slipup at the Galveston National Laboratory. Auditors last week failed to locate the material inside a freezer in the facility's Biosafety Level 4 section, which is designated for handling potentially fatal, aerially transmissible pathogens that have no known cure.
The head of the University of Texas Medical Branch, which oversees the laboratory, on Saturday said the virus had probably been destroyed but authorities were still pushing to identify the cause of the misplacement.
Guanarito and related viruses typically spread to humans through contact with infected rodents or their excretions, but "infection can also occur by inhalation of tiny particles soiled with rodent urine or saliva," according to the Centers for Disease Control and Prevention.
The Venezuelan-origin virus "is not believed to be capable of surviving naturally in rodents in the United States" or between people, UTMB President David Callender noted in released remarks.
Laboratory representatives could not be reached by press time to offer comment, but the site's scientific director told USA Today the sample -- one of five held in the same freezer -- might have caught on a piece of protective clothing and then fallen to the ground, where it would have been removed with other materials for destruction. All five samples were in place when inspectors last checked for their presence in November, he said.
"There's really no possibility of anything leaving the lab in a viable form unless it is taken out intentionally," science chief Scott Weaver added in comments to the newspaper. Decontamination showers required before leaving would complicate any effort to secrete a virus sample from the secured facility, he said.
The House Energy and Commerce Committee has begun to scrutinize possible security threats at the nation's biodefense laboratories. The Agriculture Department last year noted failures by its inspectors to identify unauthorized transfers of anthrax and plague samples, and congressional investigators this week released findings that the Obama administration had yet to follow through on their 2009 recommendation to establish a uniform code for planning, constructing and overseeing sensitive biological defense facilities.
Even though the Galveston laboratory incident has generally been attributed to a benign cause, microbiologist John Palisano warned there is "no reason to be cavalier and say we don’t have anything to worry about."
"Sometime, someone’s going to see a lapse in security and then take advantage of it," Palisano, an infectious disease specialist at the University of the South, said in a telephone interview. He called for more frequent federal inspections aimed at ensuring compliance with existing rules.