WASHINGTON — Army officials have suspended most research involving dangerous germs at the biodefense laboratory at Fort Detrick, Md., which the F.B.I. has linked to the anthrax attacks of 2001, after discovering that some pathogens stored there were not listed in a laboratory database.
The suspension, which began Friday and could last three months, is intended to allow a complete inventory of hazardous bacteria, viruses and toxins stored in refrigerators, freezers and cabinets in the facility, the Army Medical Research Institute of Infectious Diseases.
The inventory was ordered by the institute’s commander, Col. John P. Skvorak, after officials found that the database of specimens was incomplete. In a memorandum to employees last week, Colonel Skvorak said there was a high probability that some germs and toxins in storage were not in the database.
Rules for keeping track of pathogens were tightened after the 2001 anthrax letters, which killed five people. But pressure to improve recordkeeping and security at the Army institute intensified six months ago after the suicide of Bruce E. Ivins, a veteran anthrax researcher, and the Federal Bureau of Investigation’s announcement that prosecutors had been preparing to charge Dr. Ivins with making the deadly anthrax powder in his laboratory there.
A spokesman for the institute, Caree Vander Linden, said an earlier review had located all the germ samples listed in the database. But she said some “historical samples” in institute freezers were not in the database, and the new inventory was intended to identify them so they could be recorded and preserved, or destroyed if they no longer had scientific value.
One scientist, who spoke on the condition of anonymity because he was not authorized to comment, said samples from completed projects were not always destroyed, and departing scientists sometimes left behind vials whose contents were unknown to colleagues. He said the Army’s recordkeeping and security were imperfect but better than procedures at most universities, where research on biological pathogens has expanded rapidly since 2001.
The suspension will interrupt dozens of research projects at the institute, whose task is to develop vaccines, drugs and other measures to protect American troops from germ attacks and disease outbreaks. Ms. Vander Linden said some critical experiments involving animals — often used to test vaccines and drugs — would not be halted.
News of the suspension, first reported Monday by the Science magazine blog ScienceInsider, comes as the Justice Department has been interviewing scientists at the Army institute to prepare the government’s legal defense against a lawsuit filed by the family of Robert Stevens, the Florida tabloid photography editor who was the first to die in the 2001 letter attacks.
That lawsuit, filed in 2003 and delayed by the government’s unsuccessful efforts to have it dismissed, accuses officials of failing to assure that anthrax bacteria at Fort Detrick and other government laboratories were securely stored. Dr. Ivins was not suspected in the attacks at that time, but the F.B.I.’s conclusion last year added new weight to the lawsuit’s claims.
The F.B.I. has released evidence of Dr. Ivins’s mental problems and of a genetic link between the mailed anthrax and a supply of the bacteria in his laboratory. But many of Dr. Ivins’s former colleagues at the Army institute have said they are not convinced that he mailed the letters.
The F.B.I. has asked the National Academy of Sciences to convene a panel of experts to review its scientific work on the case, and the bureau and academy are completing a contract for the review, said an academy spokesman, William Kearney.
The anthrax case has underscored the threat of biological attack by biodefense insiders like Dr. Ivins, who have access to pathogens and the expertise to work with them.
The number of such researchers has grown rapidly since 2001, when the anthrax letters set off a spending boom on biodefense that led to a rapid addition of laboratories working on potential bioweapons, notably anthrax.
Before 2001, only a few dozen such facilities worked with anthrax. Today, the Centers for Disease Control and Prevention has registered 219 laboratories to do so, said an agency spokesman, Von Roebuck. He said 10,474 people had been cleared to work with dangerous pathogens and toxins nationwide after background checks by the Justice Department.
A version of this article appeared in print on February 10, 2009, on page A16 of the New York edition.