Latest on swine flu from CDC

Two recent sources of information, a conference call for clinicians and a just concluded media conference call held by CDC Acting Director Richard Besser.

Clinician call:

An emergency conference call for the Clinician Outreach and Communication Activity (COCA) was announced just hours ago on the Clinicians Terrorism and Emergency Preparedness listserv. It was "live blogged" via the Comments Thread by reader Abigail, MD. Here's the gist (lightly edited), as typed by her in real time (thanks!):

  • Update on current emergency situation - 8 individuals in US with swine flu, the hospitalized patient was immunosuppressed because of autoimmune hepatitis.
  • Unrelated to any swine influenza virus that has ever been identified in North America.Incubation period unknown but probably 1-7 days, most likely 2-5 day.
  • Mexico virus studied by CDC appears the same.
  • US cases have been uncomplicated, Mexico cases involve severe lower respiratory symptoms.
  • Clinical recommendations: Expect secondary bacterial infections and exacerbation of underlying conditions. More on CDC website.
  • There are parallel calls going on with Canada and Mexican clinicians and WHO right now. They repeat that the situation is evolving. There will be a number of documents posted on the CDC website in the next 24-48 hours. "This is just the beginning of this event."
  • No good info yet about infection in animals in US. It's "h2h ongoing transmission."
  • First known Mexican case onset 3/22

Questions from participants:

Question: Is there any explanation for the high fatality rate in mexico as opposed to US?

Answer: Don't know, but it is "quite a concern." "Current diagnostics... for seasonal influenza ... will not be able to tell you if individual has swine flu or seasonal flu." Thus it's hard to know how to treat patients with influenza symptoms in US, since swine flu is amantadine resistant and seasonal is resistant to Tamiflu.

Question: Is there discussion of upgrading WHO phase?

Answer: "Stay tuned" - discussions are ongoing.

Question: Were current cases vaccinated?

Answer: 1 of the 8 US cases received current vaccine. Others either not vaccinated or unknown. Looking at cross-reactivity with seasonal H1N1. Preliminary evidence is that the current vaccine is not a good match. Vaccine development is underway - traditional and reverse genetics - and live virus vaccine.

Question: Any plan for a CDC health advisory?

Answer: MMWR dispatch to be released today.

CDC media briefing:

In a short opening statement Besser noted that this is a follow-up to yesterday's briefing. Since then the situation has continued to evolve and CDC's concern has grown. He expects that things will change as we learn more, and that various localities in the US will likely respond in a variety of different ways. CDC considers this a strength, as it allows us to see what works well and also allows local adaptation. Because of such local variation there is also potential for confusion and conflicting information, which CDC will do its best to minimize.

One additional (mild) swine flu case has been discovered in San Diego. The concern arises from the parallel developments in Mexico, where the disease is much more severe. 14 clinical specimens from "severely ill" patients in Mexico were sent to the CDC lab and they have confirmed that 7 of them were swine flu, so far the same as the US cases, although they have yet to sequence the entire genome. Considering all the cases together, CDC has yet to get a good fix on the extent of spread or the illness spectrum (virulence).

There are no travel restrictions, but an "outbreak notice" has been issued for Mexico City and southern Mexico, alerting travelers that there is disease in those areas. CDC does not know if these developments will lead to a pandemic.

Besser then took questions from the media, although not much new information was revealed. He deflected several questions about Mexico, including the number of cases and number of deaths, by saying, "Ask the Mexicans or WHO." Similarly, he deflected questions about the age distribution (was it like 1918?). Not good.

Regarding the apparent difference in virulence between the Mexican version and the US, he said that additional sequencing of is being done to see if there are genetic differences that might explain it.

CDC is not at the point of declaring this the start of a pandemic. WHO is said to be convening its expert committee to decide whether to raise the pandemic threat level from phase 3 to phase 4 (novel virus, ongoing transmission in an area). In response to a question about whether there would be any attempt at containment, he said the obvious: the cat's out of the bag. There are scattered cases without obvious links. It has likely gone through several person to person transmission cycles and is not confined to a focus or geographic area.

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Isn't it just practical that we should expect a declaration of level 6 pandemic flu from the WHO within the next few weeks? (assuming that it continues to grow)

already mutated in less than one month while shifting northward across the US/MEX border?

CBC radio here in Canada just reported that a prosecutor, who just returned from Mexico, was hospitalized in Ottawa with a severe respiratory infection. Samples have not been analyzed yet.

Revere, two questions.

Isn't it possible that the apparent difference in virulence could reflect a much larger number of undetected cases in Mexico? After all, the U.S. cases were only found because they happened to be seen by people doing flu monitoring, who could tell they had a non-human-type H1N1. Most people with ILIs aren't tested in the U.S., and I doubt they are in Mexico either.

And in a way, that would make the news worse, because it would mean the scope of the problem in Mexico is bigger than we know.

Two, Crof reports that they're giving out a million doses of vaccine in Mexico City. I assume that means the seasonal flu vaccine, the one that's not a good match? Are they going on the theory that some possibility of cross-protection is better than nothing, or is this public health theatre?

caia: It is possible the severe cases are the tip of the iceberg, which is good and bad. The good part is that what we see there is not the full spectrum of illness. Lots of mild or inapparent disease. The bad part is that there is a lot of it around. But if it isn't very virulent, that's not bad, either. I doubt it's the case. But it might be that many of these cases are from other viruses and it isn't apparent how much bad respiratory disease is around. The H1N1 is now a part of that. That's my optimistic scenario. But I don't really believe it. I think we are definitely at Phase 4 and WHO needs to acknowledge that or lose whatever credibility they have left.

I've been away from the keyboard talking science with a collaborator so I haven't seen crof's report yet. But this may be just in the line of "we'll do whatever we can." It may even be helpful. Who knows? Probably won't hurt.

If this outbreak is happening at the end of the traditional flu season could it have any positive impact on its potential reach/scope or do these things run their course regardless of the traditional seasonal flu cycle?

And, as someone else pointed out, we don't want this reassorting with seasonal flu, because it might pick up resistance to Tamiflu. So that's another reason to vaccinate for seasonal flu.

COnsidering all the new Bio-weapons lab that were built during the Cheney/Bush era for their futur war.

Project for a New American Century, 2000:

The report calls itself a âblueprint for maintaining global US preeminence, precluding the rise of a great power rival, and shaping the international security order in line with American principles and interests.â The plan shows that the Bush team intends to take military control of Persian Gulf oil whether or not Saddam Hussein was in power and should retain control of the region even if there is no threat. It says: âThe United States has for decades sought to play a more permanent role in Gulf regional security. While the unresolved conflict with Iraq provides the immediate justification, the need for a substantial American force presence in the Gulf transcends the issue of the regime of Saddam Hussein.â The report calls for the control of space through a new âUS Space Forces,â the political control of the internet, the subversion of any growth in political power of even close allies, and advocates âregime changeâ in China, North Korea, Libya, Syria, Iran and other countries. It also mentions that âadvanced forms of biological warfare that can âtargetâ specific genotypes may transform biological warfare from the realm of terror to a politically useful toolâ

A new variant of H1N1! What a surprise. Please see my extended comments on

The CFR is about 8% in Mexico; quit severe, in fact catastrophic if this rate persists. Did this strain originate in NA or elsewhere? If elsewhere, where. If it began in China, Indonesia, or west Africa, the most likely loci by most accounts, a month or two ago, they must be overwhelmed with cases by now and this will become apparent soon as it will not be possible to hide them much longer.

Given the fact that the virus has affected so many on the North American continent already, it is likely to be everywhere within it within a very short time; days not weeks or a month.

The US DHHS predicts that global spread of the next pandemic virus will happen 30 days after outbreak anywhere on the planet. Well, if this strain is the pandemic strain, then the world will be engulfed shortly.

If we are witnessing the advent of a new pandemic, then it has come upon NA much more rapidly than predicted. Since the strain in question is already within NA, a prudent assessment is that the pandemic is already present within most of our metropolitan areas now.

Those who have prepared for this occurrence should consider activating their pandemic preparedness plans now. If this is a false alarm, it won't take long for this to be recognized.

The key is the CAR. A high case rate is the sign that this is a pandemic strain. A CFR in the low single digits signifies an moderate pandemic but one in the high single digits of low double digits sigifies a severe pandemic with catestropic consequesnces.

Grattan Woodson, MD

By The Doctor (not verified) on 24 Apr 2009 #permalink

Gratton, having fun I see. I'm glad to see that you are enjoying yourself so much.

If it began in China, Indonesia, or west Africa, the most likely loci by most accounts, a month or two ago, they must be overwhelmed with cases by now and this will become apparent soon as it will not be possible to hide them much longer.

WHO reports that the first confirmed case in Mexico was 22 March.

By D. C. Sessions (not verified) on 24 Apr 2009 #permalink

How worried by this new virus should we be.i live in the uk,and so far we have no cases of it yet.

Hey trolling MattK, at least Gratton freely gave us laypeople info on how to keep our families hydrated if push comes to shove.

Thanks, Revere and everyone else, for your steady updates.


So what should we do about the impending danger of swine flu? I think I will go get a general flu shot, buy a face mask, increase my intake of Tahitian Noni Juice and antioxidant-rich foods to bolster my immune system, make sure I get enough sleep, wash my hands before eating. Is it enough though? And if swine flu is nowhere near my home town, then I would still go to work with a cold unless it was really bad...