"Leaky" hospitals: Is CA-MRSA really HA? Or v.v?

Within the community of scientists researching MRSA — which must be getting bigger all the time, since MedLine records about 25 new papers every week — there is some tension over whether hospital-acquired or community-associated MRSA causes the most disease and early death (morbidity and mortality, in epidemiologist-speak).

The latest paper to stoke this fire was a much-reported, CDC-authored Journal of the American Medical Association paper and an accompanying commentary that were published last Oct. 17. The paper found that invasive MRSA (the most serious cases, of bloodstream infections and endocarditis for instance) causes an estimated 94,360 infections and 18,650 deaths per year. The commentary famously and accurately said that MRSA accounts for more deaths in the United States each year than AIDS does. (Paper: Klevens RM, Morrison MA, Nadle J, et al. Invasive methicillin-resistant Staphylococcus aureus infections in the United States. JAMA 2007;298:1763-71. Abstract here. Commentary: Bancroft EA. Antimicrobial resistance: it's not just for hospitals. JAMA 2007;298:1803-4. MedLine listing, but no abstract.)

An interesting feature of the Klevens paper, which was based on data from the CDC's Active Bacterial Core surveillance system, is that it re-sorts MRSA cases using a new set of definitions: community-associated, hospital-onset, and a new category they called "hospital-acquired, community-onset" — that is, colonized in the hospital but not symptomatic until after the person was discharged. Using these new definitions, the CDC group found that the vast majority of invasive MRSA cases were healthcare associated: 26.6% of the 8987 cases on which they based their study occurred while the patients were in hospital, and 58.4% after they left and were living at home again. Only 13.7 percent of the invasive MRSA cases turned out to be community-associated.

In other words, the most serious cases of MRSA look like they are CA cases, but actually are not.

That finding prompted the team to call for better infection control: "If, in fact, these infections represent acquisition during transitions of care from acute care, it follows that strategies to prevent and control MRSA among in-patients, if properly applied, may have an impact on these infections as well as on the traditional hospital-onset infections."

What's interesting about this is that it appears to return us to the "leaky hospitals" hypothesis of CA-MRSA. This view, which reigned from the emergence of MRSA in the 1960s to well into the 1990s, held that hospitals are the source of almost all MRSA cases if you just look hard enough. It was dislodged by microbiological analysis in several key papers in the late 90s, which showed that the strains causing CA-MRSA cases really were genetically different from the hospital strains.

The CDC paper seems to swing opinion back the other way, toward HA-MRSA as the source of the most serious cases of MRSA disease at least. But, here's an important point: The CDC paper bases its resorting on an assessment of risk factors, such as whether patients had prior exposure to the health care system. It does not sort the cases by microbiology: Of the 8987 cases used in the analysis, genetic-fingerprint (PFGE) results were available for only 864.

Now another group of researchers has arisen to say: That's not good enough. In a letter published in February, Michael David and colleagues of the University of Chicago Children's Hospital chide the CDC group for not considering that someone may have been in a healthcare environment, been discharged, and afterward picked up a community strain, In other words: Unless you do the microbiology, you won't know which cases are which. (David MZ, Siegel JD, Chambers HF, Daum RS. Determining whether methicillin-resistant Staphylococcus aureus is associated with health care. JAMA 2008;299:519. MedLine listing, but no abstract.)

Important note: The University of Chicago group, led by Dr. Robert Daum, were the first to challenge the "leaky hospitals" hypothesis and raise the alarm about CA-MRSA in a pathbreaking paper — really the first significant CA-MRSA paper — in 1998. (Herold BC, Immergluck LC, Maranan MC, et al. Community-acquired methicillin-resistant Staphylococcus aureus in children with no identified predisposing risk. JAMA 1998;279:593-8. Abstract here.)

So: Are healthcare strains, with their unique resistance patterns, responsible for the worst community cases? Are community-staph cases really healthcare cases in disguise? And what if community staph was causing healthcare cases as well?

More on that to come.

Rapid tests and detection of HAIs

From the New York Times' business section, a good discussion today of the new technologies that have made possible rapid detection and identification of patients colonized with MRSA.

The story focuses on Cepheid, a 12-year-old California biotech that may score its first-ever profits on the basis of its MRSA rapid test, which returns results in 60-90 minutes, compared to the several days required for a bacterial culture. (Other test manufacturers, with products already out or in the pipeline: Becton-Dickinson, Roche, GenProbe.) Among the early users: The company's own CEO, John L. Bishop, who picked up MRSA at his gym.

Rapid tests such as Cepheid's make "search and destroy" programs plausible: They return results so rapidly that hospitals can get started on treating or decolonizing patients before any staph that has been carried into the hospital can spread.

The piece does a nice job of exploring why hospitals would be opposed to "search and destroy." Among the reasons: Suspicion of being a new marketing opportunity for the test-producing companies; focusing on eradicating only one organism instead of instituting broad infection-control programs that will combat other HAIs as well.

HAI reporting: Should it be legislated?

So assume for the purposes of argument that hospitals do not eliminate hospital-acquired infections, and that the states in which they operate require them to begin public reporting of their infection rates — as a means of (choose your motivator) shaming them into doing better, or warning the public if they do not.

This argument is not hypothetical: Nineteen states have enacted HAI-reporting legislation, and another half-dozen have HA-MRSA reporting requirements, with more states considering MRSA bills this spring.

On the one hand, we know that infection control is difficult: Bugs linger not just in obvious places — walls, floors — but on essential objects with complex, hard-to-clean surfaces such as computer keyboards and stethoscopes. But on the other hand, we know that good infection control saves not only lives, but money and time as well.

So, infection control — specifically, "search and destroy" — by legislation: Fair or not fair?

A set of articles published last year argues the two sides. From Dr. Barry Farr, professor emeritus at the University of Virginia Health System, long-time leader in infection control: Legislation is not the best solution, but it should be enacted because the healthcare industry has been dragging its feet for too long. From the boards of directors of the Association of Professionals in Infection Control and the Society for Healthcare Epidemiology of America: Legislating specific actions that hospitals must take creates an unfunded mandate and may have unintended consequences.

More about hospital-acquired infections

As I said earlier, a panel of heavy hitters (and me, just the moderator) will meet later this month to debate the trend of states forcing hospitals to fess up to hospital-acquired infections. Nineteen states now require it and an additional handful have additional laws that specifically require MRSA reporting.

The unstated assumption behind those laws is that hospitals both should and can control hospital-acquired (AKA nosocomial) infections. But in the real world, the strategies for doing that are still being argued about. This is surprising, to say the least, since hospital-acquired MRSA has been brewing in the United States for 40 years. (First cite, for medical-history geeks: Barrett FF, McGehee RF Jr, Finland M.Methicillin-resistant Staphylococcus aureus at Boston City Hospital. Bacteriologic and epidemiologic observations. N Engl J Med. 1968 Aug 29;279(9):441-8.)

The tactic that has worked the best — in hospital units, whole hospitals, geographic areas and in Europe entire countries — goes by the jargon name "Active detection and isolation (ADI)" and the shorthand description "Search and destroy." Briefly, it calls for identifying new hospital patients whose recent history puts them at risk of being infected or colonized, testing them for the bug, and putting them under isolation until they are cleared of the bug.

It sounds straightforward, and currently there are about 150 studies to prove that it works. (Here is one of the most recent, about Evanston Northwestern Healthcare in Illinois.) But in the United States, hospitals take their infection-control cue from several official authorities, including the Healthcare Infection Control Practices Advisory Committee (HICPAC) chartered by the Centers for Disease Control; and a joint task force of the members of two professional organizations, the Society for Healthcare Epidemiology of America (SHEA) and the Association for Professionals in Infection Control (APIC). And those two groups do not agree: The task force says ADI should be used routinely — but HICPAC delinks detection from isolation and makes isolation just one of many options a hospital can try as a means of curbing a bug's spread.

The difference provokes furious debate among infection-control professionals, leaves hospitals confused, and has sparked a grassroots movement among families of victims of nosocomial infections. For a great overall exploration, check out Arthur Allen's recent article at the newly launched Washington Independent.

Hospital MRSA - should healthcare institutions be forced to report it?

I'll be moderating a panel exploring that contentious issue at the Association of Health Care Journalists' annual meeting in March. On the panel:

• Carmela Coyle, senior vice president for policy, American Hospital Association
• Betsy McCaughey, Ph.D., CEO and chair, Committee to Reduce Infection Deaths
• Carole Moss, executive director, Nile's Project
• Chesley Richards, M.D., M.P.H., deputy director, Division of Health Care Quality Promotion, U.S. Centers for Disease Control and Prevention

A number of states have passed laws in the past few years that require public disclosure of hospital-acquired infections, and a half-dozen have added provisions that specify reporting HA-MRSA. It seems like a no-brainer: Shame is a great motivator.

But some citizen-advocates are concerned that clever or well-funded institutions will be able to game the system. And some researchers who have evaluated infection-reporting regimes warn that surveillance often misses patients and reporting regimes are not standardized from state to state.

New MRSA article in Annals of Emergency Medicine

Well, that was fast: Here's a second article out of the book research, in the News & Perspectives section of the medical journal Annals of Emergency Medicine, where I am a "special contributor."

Brief synopsis: Emergency rooms are early-warning sites for detection of community-associated MRSA. Alert personnel there see the bug in all its manifestations, from minor skin infection to major invasive disease. They have been among the earliest voices warning everyday physicians of the need to change prescribing habits. They also, as the article discusses, may be at risk from the bug.

The story starts with an anecdote from one of my many post-Katrina reporting trips to New Orleans (stay tuned for a big story coming on that next month!):

The patient, a man in his 20s, walked into the emergency department (ED) on an autumn afternoon complaining of pain from a fist-sized lump under the right corner of his jaw.
The residents who had rounded on him recited their findings. He was not febrile. He was having no dental pain. The lump was thick-walled and unyielding and its outer temperature matched the nearby skin. Peter Deblieux, MD, director of emergency services at Louisiana State University Interim Hospital, asked for a syringe to aspirate it. ...
Deblieux masked the syringe with his free hand—the patient had confessed he was terrified of needles—slid the needle in, and smoothly pulled back. The cylinder filled with a creamy, cloudy substance streaked with red.
“It’s pus,” Deblieux said disbelievingly. “I was not expecting that.”
Ten years since it was first recognized as a significant pathogen, community-associated methicillin-resistant Staphylococcus aureus, CA-MRSA, still retains the element of surprise.

Full text is here.

The New England Journal of Medicine has put the full text one of the most important papers about MRSA in ERs (Moran GJ, Krishnadasan A, Gorwitz RJ, et al.. Methicillin-resistant S. aureus infections among patients in the emergency department. N Engl J Med. 2006;355:666–674) online for free.

MRSA article in Health magazine

After a long wait, some freelance articles that I've written on MRSA while researching the book have finally begun to be published! Here is the first, in Health magazine: an "as-told-to" by a Boston-area woman who struggled for more than a year with recurrent skin infections that just kept coming back:

The Truth About Staph
by Jilly Jackson* as told to Maryn McKenna
One woman’s harrowing tale of dealing with a dangerous infection called MRSA. How she got it and how it spread.
When I heard that high schools were closing and teenagers were dying because of the MRSA superbug, I felt lucky. Since the middle of 2006, I’ve had methicillin-resistant Staphylococcus aureus six times and somehow managed to avoid the worst: I’ve never been hospitalized and don’t fear for my life.

Link here and sidebar here.
Also, a CNN.com version — which has generated some great new leads for me! — here.