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Deadly Flu Virus Strain Inadvertently Shipped to Laboratories Around the World

April 13, 2005 at 12:00 AM EDT


RAY SUAREZ: Researchers in the U.S. and 17 other countries are racing to destroy vials of a deadly flu virus that was accidentally sent to nearly 5,000 labs around the world. The World Health Organization warned authorities last night of the need to destroy the samples of virus, which is known in the medical world as H2N2.

The strain is considered responsible for several million deaths during a pandemic outbreak in 1957 and 1958. For the latest on what went wrong and what efforts are underway, I’m joined by Dr. Julie Gerberding, the director of the Federal Centers for Disease Control. The CDC is spearheading the response in the United States.

Dr. Gerberding, welcome.


RAY SUAREZ: Why would flu virus be sent out this way in the first place?

DR. JULIE GERBERDING: Well, the reason the virus was sent out is because laboratories have to know they can detect these kinds of organisms in order to do their job so it’s a routine for labs to receive unknown samples as a test to see, can you detect this or not?

Unfortunately, in this case the College of American Pathologists and other organizations sent a strain of flu that we haven’t seen in this country since 1968, and this flu strain could be a threat to laboratory workers or the public.

RAY SUAREZ: So the mistake was not in sending out virus but in sending out one that’s so dangerous. What makes it so dangerous?

DR. JULIE GERBERDING: Well, the main reason it’s dangerous or potentially dangerous is that we haven’t seen it since 1968, so people born after that don’t have any immunity to it at all. So it may not be as serious as we expected based on the fact that this particular strain has been passed in the laboratory many, many times in the intervening years and probably has lost some of its potency, but because we can’t be sure of that, we can’t take any chances. And that’s why the request to destroy the virus has gone out internationally.

RAY SUAREZ: As of this moment there’s no indication that any of the samples were improperly handled, that anybody has been exposed to or contracted the disease?

DR. JULIE GERBERDING: Well, these laboratories are undergoing this kind of testing to get their accreditation, meaning a quality seal, so to speak. And part of that accreditation requires them to use safe procedures to prevent exposure of laboratory workers and others.

We’re not aware of any breaches in those kinds of protocols but just in case we have to take these steps. We also have been tracking influenza very carefully this past season. We haven’t seen any unusual patterns and CDC’s laboratories test the flu strains to see what kind is circulating. And we have not found a single isolate of this flu virus this year.

RAY SUAREZ: When were these samples sent out to the labs from the United States?

DR. JULIE GERBERDING: These samples have gone out since early September over a long period of time. And that’s one of the aspects of this that is reassuring. If there was a problem, we would certainly have detected it by now based on the intense surveillance that we do for influenza strains, especially this year when we were worried about avian influenza.

Our health concern right now is focusing just on those people who may have received these kits relatively recently and could be in the incubation period for flu. And, you know, that’s just a few days, so our primary health concern is for people who have had recent exposure to the virus, not the people who have been handling it over the past several months, but we are advising lab workers who have been working with these kits to monitor their health and if they have anything that remotely resembles a flu-like illness to be sure and get tested for flu and let the CDC know.

RAY SUAREZ: If the kits containing this virus have been going out since September, why did it take so long for the public to find out about this?

DR. JULIE GERBERDING: Well, what the labs were doing with these virus samples was identifying what is the virus and is it Influenza A or Influenza B? This is Influenza A. And we have all kinds of influenza A. Most laboratories would never have done additional testing to detect the fact that this was actually an old strain of Influenza A.

The reason this came to light was because there was a mix-up in a lab in Canada and they mistakenly thought the specimen had come from a patient so when they worked hard to get the details of the nature of that flu virus strain they discovered it was a virus that we call H2N2 and that was a signal that something had either newly happened or we were dealing with an old virus strain.

The detective work done by the people in Canada with some technical support from CDC and other experts really discovered the fact that it was coming from these test kits and then that led to an investigation, which resulted in our appreciating that these kits have gone out to more than 4,000 laboratories around the world over the past several months.

RAY SUAREZ: More than 4,000 laboratories. So once those samples have been sent out to so many places, how do you check what happened to them and whether they’re still floating around out there?

DR. JULIE GERBERDING: Well, what we’re doing and what the ministers of health are doing in all of the affected countries is notifying absolutely every laboratory who may have received one of these samples and alerting them of the importance to immediately destroy it and then signal that act back to the source group.

So, for example, in this country if someone had received a kit from the College of American Pathologists, they would be receiving a letter and a call saying destroy this immediately and let us know as soon as that’s happened. So the College of American Pathologists is, as we speak, documenting that all of the virus strains have been destroyed.

We’re also recommending that the destruction process be one that we know will absolutely certainly completely inactivate any of the flu virus isolates that are there. I really need to….

RAY SUAREZ: Go ahead.

DR. JULIE GERBERDING: I just want to emphasize that we are taking these extreme measures to be sure that every last virus strain is destroyed. Although we know the risk is likely to be low, we’re not taking any chances. So these are very extreme measures to be absolutely certain that there’s no residual of this virus left anywhere.

RAY SUAREZ: Well, if labs need to occasionally test their procedures, to check that they’re doing the right things in the right way and if you need a live virus to do it, what has to change about the procedures so that this kind of thing doesn’t happen again?

DR. JULIE GERBERDING: Well, one of the things that we’re concerned about is that this particular virus was selected. This would not have been something that CDC would have recommended or any other influenza expert because there’s no reason why they would have to use an old strain that we don’t have immunity in our population to. We could just simply use one of the strains that had recently circulated or this year’s flu virus strain. So there was no reason to use this particular strain.

We suspect it may have been selected because it’s known to grow very fast and it speeds up the whole testing process. So there may have been a practical issue on the mind of the laboratory who chose it. But from our perspective, from a safety perspective, it is not a choice that should be made. So what we’re going to do is take some initiative here and work with the Department of Health and Human Services under Secretary (Mike) Leavitt’s direction to really pull together some experts in this field and issue some strong recommendations about how this kind of testing should be done in laboratories and what can be done to assure that no unsafe pathogens pose a risk to laboratory workers or the public.

RAY SUAREZ: Dr. Julie Gerberding of the Centers for Disease Control, thanks a lot.