WASHINGTON — The Centers for Disease Control and Prevention has closed two laboratories in Atlanta and stopped sending out infectious agents and other biological materials from its highest-level bio-security labs due to recent safety and security lapses.The lapses include the accidental exposure of CDC lab personnel to anthrax and the previously unreported shipment of a deadly strain of bird flu to another government lab. No one has been found to have been infected.The moratorium on the shipment of biological materials will remain in place pending further investigation into the cause of the safety breaches and implementation of new lab safety measures.“These events serve as a warning that the protocols are not what they need to be to ensure that our laboratories operate safely,” said Dr. Thomas Frieden, the CDC’s director.The bird flu incident, which began at the CDC’s influenza laboratory in Atlanta, was discovered May 23 but wasn’t reported to senior CDC officials until Monday. Frieden didn’t hear of the situation until Wednesday.When asked Friday about the six-week delay in reporting the incident, Frieden said: “I can think of no valid explanation.”The incident occurred when a culture of relatively safe bird-flu virus was accidentally cross-contaminated with a highly pathogenic strain and then shipped to a Department of Agriculture laboratory in Athens, Ga. Although no exposures occurred from the mishap, the influenza laboratory has been closed and won’t reopen until new safety procedures are implemented following the investigation.The bird flu scare came to light after a June incident that potentially exposed some 75 CDC staffers in Atlanta to live anthrax. A new CDC report issued Friday said it was possible but extremely unlikely that affected lab personnel were exposed to the deadly toxin. None have become ill.Both incidents have shaken the sterling reputation of the CDC as the gold standard in the safe handling, storage and shipment of infectious agents and dangerous pathogens.“Fundamentally, what they revealed was totally unacceptable behavior,” Frieden said. “These events should never have happened. . . . “I’m disappointed by what happened and, frankly, I’m angry about it.”Staff at CDC who contributed to the incidents or were in a position to prevent them will face disciplinary action following further investigation, Frieden said.Earlier this month, six 60-year-old vials of smallpox virus were found in a storage room on the National Institutes of Health campus in Bethesda, Md. Frieden said that discovery and the bird flu and anthrax scares were enough for people to reasonably question the federal government’s ability to safeguard the health of the public and its own employees.“The problem was not in the creation of the materials but in the inventory control, which allowed them to remain unsecured for decades,” Frieden said of the smallpox.Tests by the CDC have shown that two of the vials contained smallpox that was viable, or alive.“Two of the six vials showed evidence of growth,” Frieden said. Scientists at the CDC will analyze the genetic sequence of the smallpox and then destroy the vials and culture materials. “That’s what should have been done a couple of decades ago. And that’s what will be done now,” Frieden said.Representatives from the World Health Organization will witness the destruction of the smallpox, which was created in February 1954, Frieden said. The entire NIH campus is being swept to see whether other dangerous stray materials are present. The CDC is monitoring the process.In the new report on the anthrax scare, the CDC found that on June 5, a lab scientist in the Bioterrorism Rapid Response and Advanced Technology laboratory in Atlanta mistakenly used a process that “they thought would kill the anthrax material, and it may not have” killed all the spores, Frieden said.As a result, workers in other CDC labs that received materials from the bioterrorism lab could have been exposed to anthrax, although it’s highly unlikely, Frieden said. “The root cause, fundamentally, was that the scientist failed to follow a scientifically derived and reviewed protocol that would have assured that anthrax was inactivated and that the material was confirmed to be sterile before it ever left the lab. That should have happened and it didn’t,” Frieden said.The resulting investigation revealed numerous problems at the lab, including a lack of standard operating procedures and oversight, the use of unapproved sterilization techniques for anthrax and the improper transfer of materials that hadn’t been confirmed as inactive.“In fact, the use of anthrax at all for this experiment should not have been done,” Frieden said. “It was not appropriate. And there was a lack of scientific knowledge in this laboratory about inactivation” of anthrax.The bioterrorism lab has ceased operations pending an investigation, implementation of new safety procedures and work to decontaminate affected areas.Frieden said he was most distressed by the procedural breakdowns that had led to the bird flu scare at the CDC’s influenza laboratory, which is also closed pending an investigation.The harmless bird flu was being prepared for shipment to another laboratory when it was contaminated with a highly pathogenic H5N1 influenza, which has caused large outbreaks in domestic poultry in Asia and the Middle East.When the other lab received the bird flu shipment from the CDC, it was tested and found on May 23 to be contaminated with H5N1. The CDC was notified and it confirmed that the contamination had occurred in its lab.Although H5N1 doesn’t usually infect humans, there have been 650 human cases reported in 15 countries since 2003, according to the World Health Organization. About 60 percent of those people have died.The investigation is underway to determine how the cross-contamination occurred. Frieden said, “We may not know for certain exactly what happened, but we’ll do everything we can to find out.”To prevent future problems, Frieden will appoint Dr. Michael J. Bell to be the CDC’s director of laboratory safety. The agency has established a high-level internal working group to review safety on a lab-by-lab basis. An external advisory group is also being formed to study the problem.