MRSA and H1N1 "swine" flu - still not a lot of evidence

Hello again, constant readers. It's busy out there.

The CDC said Wednesday that new infections with the novel H1N1 virus (Formerly Known As Swine Flu) may be trending down. Nevertheless, there is still a lot of rumor and speculation out there regarding what role MRSA pneumonia may have played in serious cases.

The CDC commented on this in its May 19th press briefing:

Q: Is anybody looking for, and is anybody finding any evidence of, coinfection with MRSA?
A: We′re very interested in that question. As you know, the seasonal influenza in children we′ve been tracking pediatric deaths, and we have seen MRSA among seasonal flu cases in children at a higher rate than we had expected. MRSA is a big problem in the United States right now in terms of the community associated resistant staff or its infections. So far as we′ve been looking at the patients with the H1N1 virus, we don′t have evidence of coinfection. Not everybody has been tested for bacterial infections. But among the ones that have been tested, we aren′t seeing an important role for bacterial coinfection, including MRSA. I think this is an important issue for us to continue to follow, whether bacterial co-infections or bacterial pneumonias following the illness are featured. It′s a feature we′re interested in but haven′t seen this turn up yet.

We've talked a number of times before here about MRSA necrotizing pneumonia, and about the apparent importance of secondary bacterial infections to the death rates in prior flu pandemics.

But for anyone who needs a refresher, I recommend an excellent new paper by researchers at Emory University, published last week in the journal Lancet Infectious Diseases. It recounts the clinical course of two people who were treated at Atlanta's Grady Memorial Hospital for MRSA pneumonia. Both were adults, and both survived, but their courses were complicated; the clinicians note that they did not improve until they were given additional antibiotics aimed at shutting down MRSA's toxinproduction, a step that is not universally considered by doctors treating a MRSA patient.

The cite is: Hidron, AI et al. Emergence of community-acquired methicillin-resistant Staphylococcus aureus strain USA300 as a cause of necrotising community-acquired pneumonia. Lancet Infect Dis. 2009 Jun;9(6):384-92. The abstract is here.

MRSA in space

No, really — but not quite the way you think. The weekly geekfest that is Aviation Week and Space Technology reports that the payload of the space shuttle Atlantis includes a MRSA experiment. The goal is to investigate whether bacteria held in the microgravity of space become more virulent — this was done earlier with salmonella — and then to determine whether any new virulence markers suggest targets for a potential staph vaccine.

A vaccine of course, is the Holy Grail of MRSA research — and it has remained frustratingly out of reach. For a great review of past research and future challenges, see this review article from March.

MRSA in the House of Lords — the silly, the serious

Thanks to constant reader Pat Gardiner, we have the transcript of the UK House of Lords discussion on community MRSA, called there PVL-MRSA after the toxin. (Go to the linked page, and click down to the time-mark 3.16 pm.) It's encouraging to see some members of a government taking MRSA seriously. The members are asking for

• better surveillance
• better infection control
• consideration of MRSA as a notifiable disease
• and promotion of both vaccine research and point-of-care diagnostics.

Hear, hear to Baroness Masham of Ilton for bringing it up.

To get to that discussion, though, you'll have to click down through some silliness (the ghost of Monty Python is never far from the British government, is it?): a discussion at time-stamp 3.07 p.m. of whether a House of Lords restaurant can afford to serve British bacon, rather than Dutch bacon, given that British bacon is almost twice as expensive and Dutch pigs are associated with MRSA ST398:

Lord Hoyle: My Lords, I thank the noble Lord for that reply, although there is more than a whiff of hypocrisy about it. After all, I and many others on all sides of the House have argued that it should not be a matter of price. We have urged the British consumer to buy British bacon because of the higher welfare standards that are applied in this country. Will the noble Lord also take into account the presence in Dutch bacon of a deadly form of MRSA, ST398, which can cause skin infection, heart trouble and pneumonia? Is he not putting people in this country at risk, particularly as the strain has passed from animals to humans? Indeed, when Dutch farmers go into hospital, they go into isolation. Why is he putting the British consumer and those who buy bacon in this House at risk in this way?

The discussion quickly devolves into foolishness about British Tomato Week — but if you read carefully, you'll see that behind the silliness, there are serious issues at stake: animal welfare, farming standards, truth in labeling (the Lord Bishop of Exeter advances the very newsworthy claim that pork imported from other countries is subsequently labeled "British" only because it is packaged in the UK) and movement of zoonotic pathogens across national borders thanks to globalized trade.

Sadly, the leader of the discussion — the Chairman of Committees, AKA Lord Brabazon of Tara (no, really) — appears not to have been keeping up with the news, since he notes of ST398:

As far as MRSA is concerned, I read the article in, I think, the Daily Express a couple of weeks ago. I do not think that it has been followed up by anybody else.

Apparently the Lord's staff have not been keeping up, since MRSA in pigs in the EU has been covered by the Daily Mail, the Independent, comprehensively by the Soil Association, and by, ahem, us.

While taking a flu break, a MRSA round-up

Constant readers, the H1N1 (Virus Formerly Known as Swine) Flu story remains a bit intense. I've missed a few MRSA stories over the past few days, so here is a round-up.

First, though, if you're curious about what the swine flu reaction says about our ability to handle a pandemic, you might take a look at this story I wrote Friday at CIDRAP. Quick version: Over-reaction on the part of the "worried well" — and people seeking testing and not knowing where to get it — put ERs into meltdown nationwide. If we were facing a virus that was not only fast-spreading but virulent, we could be in serious trouble.

On to MRSA:

• Therapy animals as a vector: In a letter to the Journal of Hospital Infection, Drs. J. Scott Weese and Sandra L. Lefebvre of the Ontario Veterinary College at the University of Guelph report on two therapy dogs that became transiently colonized with C. difficile (on its paw pads) and MRSA (on its coat; found on the hands of its handler) after visiting health care facilities, demonstrating how easily bacteria can move in and out of hospitals. Constant readers will recognize Weese's name: He is one of the most important investigators of MRSA in food animals and pets, and among other things has written infection-control guidelines for therapy animals.
• In the Canadan Medical Association Journal, Drs. Anne G. Matlow and Shaun K. Morris of the University of Toronto and the Hospital for Sick Children caution that while hospitals may be getting better at infection control, there is not yet as much attention to it as there should be in ambulatory-care settings: urgent care centers, surgery centers and doctors' offices. They offer a checklist of the minimal things that a physician practice should do.
• And in the UK, Baroness Masham of Ilton, a member of the House of Lords, offers her online notes on serious infections with community MRSA, which the Brits are calling PVL-MRSA in recognition of the toxin that the strain produces. The notes are in advance of a series of questions that she intends to pose to government ministers during a Question Time on Wednesday.

More soon.

MRSA strains crossing borders: US CA-MRSA to Italy

Swine flu continues to dominate the headlines, but other pathogens don't read the papers. Case in point: New news about a US community strain being found and treated in a woman in Italy — better treated, as it turns out, than she was in California, where she was infected.

In a new letter in Emerging Infectious Diseases (a free journal published online and in print by the CDC — it's your tax dollars at work, just read it, already), Carla Vignaroli, Pietro E. Varaldo, and Alessandro Camporese of the Polytechnic University of Marche in Ancona amd the Santa Maria degli Angeli Regional Hospital, Pordenone report the case of

a 36-year-old Italian woman (who) was seen at Pordenone Hospital (northeastern Italy) for spider-bite–like skin lesions on the face, characterized by rapid evolution to furuncles and small abscesses. The infection had started ≈1 month earlier in California, where she had spent several months on business (wine import-export), and where she had been treated empirically with amoxicillin/clavulanate for 10 days (1 g, 3×/day), with no clinical improvement.

(At this point, I know every clinician reader and everyone who has had a MRSA skin infection is shaking his or her head. Surely by now the knowledge that "spider bite" is practically diagnostic for CA-MRSA has penetrated? But apparently not, since she was given amoxicillin/clavanulate, AKA Augmentin, which is partially penicillin-based.)

When the woman's lesions were cultured, they turned out to be caused by USA400, the original community strain, which back in the 1990s was known as MW2. That's interesting, especially in California, since USA300 has become such a dominant strain. Nevertheless, the key point is that USA400, as with USA300, has barely been recorded in Italy:

All 3 previously reported cases of CA-MRSA infection in Italy were caused by type IV SCCmec, PVL-positive strains, none of which, however, belonged to the ST80 clonal lineage that predominates in Europe (7). The first case (in 2005) was a necrotizing pneumonia caused by an ST30 isolate; the 2 other cases (2006) were severe invasive sepsis and a neck abscess, both caused by ST8 (USA300) isolates.

The concern, of course, is that once imported, they will not remain rare:

The case we note here documents the importation of a US pathogen into a country in Europe, from an area where the pathogen is widespread and has been highly virulent since the late 1990s, to an area where its penetration in the past has been poor.

The cite is: Vignaroli C, Varaldo PE, Camporese A. Methicillin-resistant Staphylococcus aureus USA400 clone, Italy [letter]. Emerg Infect Dis. 2009 Jun; [Epub ahead of print]. DOI: 10.3201/eid1506.081632

Quick update: Yes on bacterial pneumonia and new flu.

Constant readers, I thought you;d like to know that there are a few more indications that secondary bacterial pneumonia (as discussed in this post the other day) does seem to be playing a role in the severe cases of the new flu.

That's according to this account of the WHO's technical briefing from Wednesday, along with this item (there are three entries, go to the bottom one) from the excellent disease-alert list ProMED.

More soon.

Special extra for disease-detection wonks

Constant readers: Some of you know that my first book, published five years ago, was a narrative and history of the CDC's Epidemic Intelligence Service, the young, committed corps of MDs and PhDs who give up two years of their lives to serve on front-line outbreak SWAT teams.

The EIS are very important right now, because there are almost 100 CDC people in the field, in Mexico and in US cities and other countries where H1N1 swine flu is emerging.

My next book — the one for which this blog is the whiteboard — is being published by the same imprint, Free Press, part of Simon & Schuster. So because the EIS is so crucial to the outbreak investigation, FP has relaxed their rights and very graciously allowed me to fling up some parts of Beating Back the Devil on the web, for free, to my regular readers.

My web skills are not magnificent, and my site has outgrown the program I used to build it. However: If you go to this page, you'll see a section that announces Excerpts! And in it you'll find a prologue and two chapters in various formats. (We did this fast; it is messy. Sorry.)

I particularly recommend Chapter 13 [pdf], which is a narrative of the SARS outbreak in Asia, starting with an EIS officer named Dr. Joel Montgomery staring down a tray of blood samples in a laboratory in Vietnam. (I wrote about the importance of serology — blood-analysis — surveys to swine flu at CIDRAP tonight.) The description of that outbreak response should give you a good flavor of what the CDC investigators are doing and thinking about now. And, bonus, it talks about some little-known cases of avian flu H5N1; we did not know at the time how important those cases would turn out to be.

If you have time, there are also links to sections that FP has posted on their own site: Chapter 1, which will tell you who the EIS are and why the corps exists (Korean War veterans will know already); and the book's Prologue, which takes you inside the first bioterror-response training that EIS members ever endured.

I hope you enjoy.

World MRSA Day, coming in October

Folks, MRSA activist Jeanine Thomas, who helms the group MRSA Survivors Network and was substantially responsible for getting Illinois to pass its MRSA reporting legislation, is heading the movement to observe World MRSA Day on Oct. 2, 2009.

Jeanine has been tireless in pressing for reform despite her own MRSA injuries. Please consider visiting her site and checking out the network and the October observance.

For flu wonks: Hear from a CDC expert on novel H1N1 "swine" flu

Folks, I am a member of the Association of Health Care Journalists, a US-based organization of 1,100 journalists from North America and elsewhere committing to practicing science/health/medical journalism to a high standard. (No matter how much the collapse of the MSM undermines us. But that's a different blog post...)

One of the things the AHCJ tries to do is to get its membership in direct touch with newsmakers as much as possible. We have a conference, we have podcasts, we have newsmaker briefings. And on Tuesday, we had a live webcast/call-in with Dr. Carolyn Bridges, associate director for epidemiologic science in the influenza division of the CDC, taking questions for 45 minutes on aspects of the new flu.

Participation in the call was limited to AHCJ members, but the archived version is open to all on BlogTalkRadio. Link is here.

(And yes, the moderator/interviewer is, umm, me.)

More on MRSA and the new flu

Constant readers, I admit it: I am a bad blogger. The wave of news on the novel H1N1 (AKA the Virus Formerly Known as Swine) has been just overwhelming. Apologies for disappearing.

Out of the crashing surf, though, I picked up an interesting tidbit that speaks to our concerns about MRSA. Here's some background: If you have been following the swine flu story, you'll have noticed that one of the puzzles has been why the Mexican experience has been so different from the United States or from the other countries where this flu has appeared briefly. (North America so appears to be the only area in which there is sustained transmission.) Among the hypotheses:

• There is a difference in the medical care that victims are receiving.
• There is a statistical artifact: The serious cases are a tiny percentage of the mild cases, and the US has not seen enough cases to, probabilistically, experience significant serious cases yet.
• Or, corollary to the above: Mexico has many more cases than its surveillance systems have been able to count, and that is why we have seen that (unknown but presumably tiny) percentage that become serious cases appear there but nowhere else.

(For more on this, here's a CNN story from a few days ago, quoting me and people much more distinguished than me.)

But a commentary by a global-health expert raises another hypothesis, one that brings this outbreak around to our concerns: the possibility that the serious flu cases in Mexico are being complicated by secondary pneumonia caused by MRSA or other bacteria.

We've talked about this issue before (see this post about the importance of MRSA in a flu pandemic and this paper by, among others, Dr. Anthony Fauci, director of NIAID, and Jeff Taubenberger, PhD, co-discoverer of the virus of the 1918 flu). MRSA pneumonia secondary to flu infection is the etiology of the necrotizing pneumonia cases that kill children very quickly, and is the reason why I keep haranguing you regarding flu shots.

Is bacterial pneumonia playing a role in the current epidemic? It's too soon to tell; there is not sufficient clinical data. But it is an interesting speculation and one that we should keep in mind as this goes forward.