CDC: Swine Flu Lacks Deadly Genes

The Centers for Disease Control and Prevention said Friday the swine flu virus appears to be about as contagious as the average seasonal flu. In examining the virus, it also did not find the genes they think made the infamous 1918 flu so deadly. Dr. Sylvie Briand, acting director of the Global Influenza Program for the World Health Organization, offers her insight.

Copyright © 2009 NPR. For personal, noncommercial use only. See Terms of Use. For other uses, prior permission required.


This is ALL THINGS CONSIDERED from NPR News. I'm Robert Siegel.

As new cases of swine flu crop up around the world, scientists are learning more about the virus that causes the illness. Information from the Centers for Disease Control and Prevention today suggests that H1N1 may be a milder virus than had been feared. For one thing, the CDC said the virus appears to be about as contagious as the average seasonal flu, and the virus apparently does not contain the gene suspected of making the infamous 1918 flu so deadly.

Well, joining us from outside Geneva is Dr. Sylvie Briand who is the acting director of the Global Influenza Program for the World Health Organization.

Welcome to the program, Dr. Briand.

Dr. SYLVIE BRIAND (Acting Director, Global Influenza Program; World Health Organization): Yes.

SIEGEL: And the CDC this afternoon says that the H1N1 virus lacks several of the genes that made the 1918 pandemic virus so deadly. Does that mean that we can breath easier now?

(Soundbite of laughter)

Dr. BRIAND: Well, I mean the fact that this virus differs a little bit from this 1918 virus, in fact, is a good news. And I think the first epidemiological figures we have seen shows that, in fact, most of the patients have mild symptoms. So it…

SIEGEL: Mm-hmm.

Dr. BRIAND: …gives us optimism.

SIEGEL: Our initial information about the outbreaks in Mexico, I understand, were mostly in hospital patients, not in the general population. Did those accounts give us an accurate or inaccurate picture at the outset of what this flu was all about?

Dr. BRIAND: No. I think that the difficulty in Mexico is that they had the normal seasonal influenza, let's say. So the beginning of the outbreak, it was very difficult to know if this was just a second peak in the influenza season for an unknown reason, or if it was a new virus. So I think they started to get worried when they saw that the second peak was also accompanied by some severe cases, and this is where the alert was raised at that time.

SIEGEL: And in Mexico, what should be done now in Mexico if, indeed, there is a population of people infected that's substantially larger than anywhere else in the world?

Dr. BRIAND: Well, I think the government of Mexico has taken the right measures. I mean they try now to slow down the transmission so that they can win time and put in place enough treatment and organize health care facilities to be able to treat severe patients the best way they can.

SIEGEL: How important is getting an answer to the question of why this flu sickened people worse in Mexico than it did in the U.S.? Do you need to have that answer in order to proceed or is it an interesting academic detail but one you could live without knowing the answer to for now?

Dr. BRIAND: Well, first, at the beginning of the epidemic they were recording the deaths of pneumonia, severe pneumonia.

SIEGEL: Mm-hmm.

Dr. BRIAND: But some of these cases were probably not influenza H1N1, so…

SIEGEL: You think that it may have been over reporting the deaths at the outset.

Dr. BRIAND: Yeah. At the beginning, they were counting symptomatic pneumonia and which is, in fact, the best way to start to have an estimate of the phenomenon but not necessarily completely accurate. This is one possible explanation of the apparent severity of the flu in Mexico. But maybe other factor are also influencing the severity. And this is not an academic question. We really want to understand why it - apparently it's more severe. Because if we can have a clear idea of this factor, we can also anticipate how severe could the disease be in countries with a similar social economical pattern.

SIEGEL: Well, it's been a week of much worrying about this, certainly throughout the United States and in much of the world. Are you any less worried at the end of the week than you were at the beginning?

Dr. BRIAND: Well, I think, of course, there are concerns and we are worried and we are following this very carefully. But most of the WHO messages were more to raise the alert and say to people, okay, this is something not usual and you should be prepared because we still cannot predict how it will evolve, how it will unfold, and how fast it will spread. So, and this was a warning message, basically. And some people get prepared. We don't know yet.

SIEGEL: Well, Dr. Sylvie Briand of the World Health Organization, acting director of the Global Influenza Program there in Geneva, thank you very much for talking with us today.

Dr. BRIAND: Bye.

Copyright © 2009 NPR. All rights reserved. No quotes from the materials contained herein may be used in any media without attribution to NPR. This transcript is provided for personal, noncommercial use only, pursuant to our Terms of Use. Any other use requires NPR's prior permission. Visit our permissions page for further information.

NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR's programming is the audio.



Please keep your community civil. All comments must follow the Community rules and terms of use, and will be moderated prior to posting. NPR reserves the right to use the comments we receive, in whole or in part, and to use the commenter's name and location, in any medium. See also the Terms of Use, Privacy Policy and Community FAQ.