Maryn McKenna

Journalist and Author

News break: Hospital-acquired MRSA trending down – but why?

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There’s good news today in the Journal of the American Medical Association: A 4-year study by the CDC and its partners in the Active Bacterial Core Surveillance System reports significant declines in invasive MRSA infections contracted in hospitals. The study, which covers 2005 through 2008, finds a decline of 9.4% per year among infections that were contracted in hospitals and also diagnosed there, and a parallel decline of 5.7% per year in what the CDC calls “hospital-acquired community-onset” infections, ones that were acquired in the hospital but didn’t become evident until after the patient was discharged. Overall, the decline over the study period of hospital-onset infections was 28%, and the decline in hospital-acquired community-onset infections was 17%.

MRSA is the leading organism in the vast national epidemic of hospital-acquired infections (HAIs), which conservatively sicken 1.7 million Americans per year and kills 99,000 of them. (Those numbers date back a decade to an Institute of Medicine report, and have been challenged by Consumers’ Union as an underestimate.) So any solid indication that the epidemic is decreasing is good news. And the CDC study is a solid indication, built on a population-based survey that covers about 15 million people in 9 geographical areas.

So it’s a great pity that we don’t really know why MRSA has declined in this fashion. The study can’t tell us. And because we don’t know, we’ll find it harder than it ought to be to keep the trend going in the appropriate direction.

Here’s the problem: Though it is about healthcare infections, this study doesn’t use data from hospitals. The study itself says: “National data describing changes in incidence in US healthcare institutions are not available.” The data that hospitals report on infections that occur within their walls or result from their actions, contained in the CDC’s National Healthcare Safety Network,  is voluntary, partial and anonymous; in fact, to participate, hospitals are guaranteed confidentiality. The only surveillance systems in the US where hospitals are not anonymous are the various states where legislators, out of exasperation or in response to citizen pressure, have passed laws mandating that infections be reported.

So the declines in MRSA incidence that are reported in this study can’t be linked to specific practices — and that’s important, because for more than a decade, American healthcare has been locked in a ferocious argument over the best way to reduce MRSA and other HAIs in hospitals.

On the one hand, there are institutions such as the Pittsburgh VA (in a project partially funded by the CDC and since adopted across the entire VA) and Evanston Northwestern Healthcare (now called Northshore University Health System) that follow some variant of “active surveillance and testing” or simply “search and destroy,” which tests incoming patients for MRSA carriage and isolates and treats them until they are clear. On the other hand, there are institutions that reject “search and destroy” as too MRSA-specific (and too dependent on expensive rapid-test technology) and opt instead for broader infection-control programs with special emphasis on hand hygiene and antibiotic stewardship. (This paper by physicians from Virginia Commonwealth University summarizes the issues well.) The patients whose data ended up in the JAMA CDC study might have attended hospitals that followed either of these paths, or neither. There’s no way to know.

In addition, a significant proportion of the decline in the CDC study fell into the category of bloodstream infections — which are now also being targeted by the checklist approach espoused by Macarthur Fellow Dr. Peter Pronovost and New Yorker writer and surgeon Dr. Atul Gawande, and adopted patchily across the US. Plus, there’s a further confounder: Since 2009, the Center for Medicare and Medicaid Services has been applying a carrot-and-stick approach — refusal to reimburse for the extra care needed — to certain preventable hospital-caused conditions, including central-line associated bloodstream infections (which are caused by a variety of organisms including MRSA). How successful that has been, or how much influence it has exerted, has not been assessed.

So, to recap: MRSA appears to be declining in hospitals; that’s good. From this study, we can’t say why: That’s frustrating. And, one more point: If we had truly accountable, truly transparent hospital reporting for preventable infections and other medical errors, we would not be in this data fog. Surely it’s past time to clear the air.

Cite:
Kallen AJ, Mu Y, Bulens S et al. Health Care–Associated Invasive MRSA Infections, 2005-2008. JAMA. 2010;304(6):641-647. doi:10.1001/jama.2010.1115
Accompanying editorial:
Perencevich EN, Diekema DJ. Decline in Invasive MRSA Infection: Where to Go From Here? JAMA. 2010;304(6):687-689. doi:10.1001/jama.2010.1125

Hospitals want patients to eat antibiotic-free meat

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Huge news, and hat tip to excellent food-policy writer Monica Eng at the Chicago Tribune: In a piece published Tuesday, she details that 300 hospitals in the Chicago area and nationwide have begun preferentially buying and serving meat that is raised without the use of antibiotics.

Using the ingredients is primarily a response to patient demand, said (Carolyn Lammersfeld, national director of nutrition at Cancer Treatment Centers of America) but the centers are also “watching the controversy over the nontherapeutic use of antibiotics and their potential to cause resistant strains of bacteria.”

The issue is of particular concern for cancer patients, who have compromised immune systems, she noted. “Many also might already being taking antibiotics, so they don’t want additional ones in food if they can avoid it,” Lammersfeld said.

The drug-free meat is more expensive, but the cost balances out within the budget:

(Diane Imrie, director of nutrition services at Fletcher Allen Health Care in Vermont) estimated that her food costs rose about $67,000 last year when she switched to antibiotic-free chicken from conventional. “But that’s also about the same cost as treating a single MRSA infection,” she said.

It’s interesting to see this story land just as a new paper in Foodborne Pathogens and Disease is making the rounds. The paper (Jiayi Zhang, Samantha K. Wall, Li Xu, Paul D. Ebner. “Contamination Rates and Antimicrobial Resistance in Bacteria Isolated from “Grass-Fed” Labeled Beef Products,” doi:10.1089/fpd.2010.0562) compares the bacterial burden in grass-fed and conventionally raised beef and finds no significant  differences: equivalent amounts of both drug-sensitive and drug-resistant bacteria in both types of beef. 
It concludes, “There are no clear food safety advantages to grass-fed beef products over conventional beef products” — an assertion that’s likely to be seized on by those who see no need to change current antibiotic use in agriculture. (For an example of that POV, here’s the testimony from last week’s House of Representatives hearing by Richard Carnevale, DVM of the Animal Health Institute.)
I suspect though that the paper’s analysis doesn’t look far enough. Here’s one example: the authors found that Enterococcus species in both conventional and grass-fed meat were resistant to chloramphenicol, erythromycin, flavomycin, penicillin, and tetracyline — drugs that are used in agriculture (and that could have been given to the grass-fed animals, which were not guaranteed to have been raised drug-free). But  Enterococcus spp. isolates from conventional beef were more frequently resistant to daptomycin and linezolid — which are new-to-market drugs of last resort in human medicine that are not given to animals.
That finding, right there — the migration of resistance to a human-only drug into an organism carried by an animal — signals one of the insoluble problems of overuse of antibiotics. Once created, resistance factors move horizontally among bacteria, from the farm to humans, and apparently in this case, from humans to the farm as well. We have almost no control over their movement, and on the agricultural side, almost no surveillance to detect it, either. That argues for reducing the overuse of antibiotics in human medicine and on the farm. 
If this health care coalition’s refusal to purchase meat raised using antibiotics helps to enlarge the market for drug-free meat, then it may reduce ag antibiotic use, and therefore the selective pressure that encourages resistant organisms to emerge. That can only be a good thing.
(The paper in Foodborne Pathogens has also been covered by my former colleagues at CIDRAP; here’s their link.)

Catching up to MRSA news (not about me)

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Constant readers: I’m looking forward to having the breathing space to get back to in-depth blogging. Meanwhile, though, news is zipping by — so here’s a quick list of recent things worth reading.

“Cows on Drugs” — a superb history of the 30-year-old fight to get unnecessary antibiotics out of food animals. Note, written by a former commissioner of the Food and Drug Administration, not exactly a wild-eyed radical:

More than 30 years ago, when I was commissioner of the United States Food and Drug Administration, we proposed eliminating the use of penicillin and two other antibiotics to promote growth in animals raised for food. When agribusiness interests persuaded Congress not to approve that regulation, we saw firsthand how strong politics can trump wise policy and good science.Even back then, this nontherapeutic use of antibiotics was being linked to the evolution of antibiotic resistance in bacteria that infect humans. To the leading microbiologists on the F.D.A.’s advisory committee, it was clearly a very bad idea to fatten animals with the same antibiotics used to treat people. But the American Meat Institute and its lobbyists in Washington blocked the F.D.A. proposal.

 Antibiotic resistance in your kitchen, playroom, car... — After years of begging from health advocates, the FDA and EPA are taking a second look at the chemical compound triclosan, an antibacterial that is put into, well, almost anything you can name: soaps, hand sanitizers, cutting boards, toys. Triclosan is suspected of interfering with hormone regulation in the body, and also increases resistance in organisms in our environment. (When I ask you to use hand sanitizers that contain only alcohol or salts, not antibacterials, triclosan is one of the things I’m thinking of.) The FDA will report its findings in a year. I’d rather see it happen sooner, but it’s a great move.

No progress on hospital-acquired infections — The Agency for Healthcare Research and Quality, part of the Department of Health and Human Services, has published its 2009 National Healthcare Quality Report. The news is not good. To quote the agency’s own language: “Very little progress has been made on eliminating health care-associated infections.” This is all hospital-acquired infections, not just MRSA, but MRSA is a leading organism. The ugly details:

  • Post-operative bloodstream infections up 8%
  • Post-operative catheter-associated urinary-tract infections up 3.6%
  • “Selected infections due to medical care” up by 1.6%
  • Bloodstream infections as a result of central lines unchanged.

(NB, three professional organizations — the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, and the Association for Professionals in Infection Control — put out a statement in response to this report saying it “presents an outdated and incomplete picture on healthcare-associated infections (HAIs) in our healthcare system.” The gist of the statement seems to be that they’ve got better numbers coming… soon. When there’s actual data, I’ll let you know.)

MRSA research round-up: hospitals, vitamins, pets

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Because I’ve been so behind, there’s so much to cover! So let’s dive in:

In today’s Archives of Surgery, researchers from Seattle’s Harborview Medical Center report that one simple addition to the routine of caring for trauma patients made a significant difference to the patients’ likelihood of acquiring a hospital-associated infection: bathing them once a day with the antiseptic chlorhexidine (in an impregnated wipe). Patients who were bathed with the antiseptic wipe, compared with patients wiped down with an inert solution, had one-fourth the likelihood of developing a catheter-related bloodstream infection and one-third the likelihood of ventilator-associated MRSA pneumonia. Cite: Evans HL et al. Effect of Chlorhexidine Whole-Body Bathing on Hospital-Acquired Infections Among Trauma Patients. Arch Surg. 2010;145(3):240-246.

How important are hospital-acquired infections? Here’s a piece of research from a few weeks ago that I sadly failed to blog at the time: Just two categories of HAIs, sepsis and pneumonia, account for 48,000 deaths and $8.1 billion in health care costs in a single year. Writing in the Archives of Internal Medicine, researchers from the nonprofit project Extending the Cure analyzed 69 million hospital-discharge records issued in 40 states between 1998 and 2006. Hospital charges and number of days that patients had to stay in the hospital were 40% higher because of those infections, many of which are caused by MRSA — and all of which are completely preventable. Cite: Eber, MR et al. Clinical and Economic Outcomes Attributable to Health care-Associated Sepsis and Pneumonia. Arch Intern Med. 2010; 170(4): 347-53.

 What else could reduce the rate of MRSA infections? How about Vitamin D? South Carolina scientists analyze data from the NHANES (National Health and Nutrition Examination Survey 2001-2004), a massive database overseen by the CDC, and find an association between low blood levels of Vit. D and the likelihood of MRSA colonization. More than 28% of the population is Vitamin D deficient. MRSA colonization is increasing in the US. Can giving Vit. D decrease MRSA carriage? More research needed. Cite: Matheson EM et al. Vitamin D and methicillin-resistant Staphylococcus aureus nasal carriage. Scand J Infect Dis. 2010 Mar 8. [Epub ahead of print]

And finally: Who else carries MRSA? Some unlucky pet owners have found that animals can harbor human strains, long enough at least to pass the strain back to a human whose colonization has been cleared. So it makes sense to ask whether humans who spend time with pets are carrying the bug. Last month’s Veterinary Surgery reports that the answer is Yes. Veterinarians are carrying MRSA in very significant numbers: 17% of vets and 18% of vet technicians at an international veterinary symposium held in San Diego in 2008. Cite: Burstiner, LC et al. Methicillin-Resistant Staphylococcus aureus Colonization in Personnel Attending a Veterinary Surgery Conference. Vet Surg. 2010 Feb;39(2):150-7.

Recommending: Consumer Reports on hospital infections

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Constant readers, the magazine Consumer Reports has done an extended, state-by-state analysis of which hospitals do well, or very badly, in preventing one important category of infections: central line-associated bloodstream infections, or CLABSIs (pronounced klab-sees). It’s a comprehensive package in easily understandable language. It’s based on the state reporting data that some activists have managed to persuade states to disclose, along with another set of data that some hospitals voluntarily tender to the nonprofit firm The Leapfrog Group.

From the Consumer Reports story:

Poorly performing hospitals included some major teaching institutions. For instance, New York University Langone Medical Center in New York City reported 39 infections in 10,119 central-line days in 2008, roughly twice the national average for its mix of ICUs. The University of Virginia Medical Center in Charlottesville didn’t do much better, reporting 77 infections in 18,572 days for the 15 months ending in September 2009, also about two times the national average.

More encouragingly, nationwide, we counted 105 hospitals whose most recent public reports tallied zero central-line infections. They ranged from modest rural institutions to urban giants such as the University of Pittsburgh Medical Center Presbyterian hospital, which reported no infections among patients who were on central lines a total of 13,596 days in 2008.

It’s well worth reading, and checking to see whether a hospital you may have used, or may be considering using, is on the good list or the bad list. Take a look.

MRSA in the journal Science – spread, outbreaks and an argument for active surveillance

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I have a story tonight at CIDRAP about a paper published this evening in the journal Science. To respect fair use and make sure my colleagues get clicks, I just quote the story here — but then I want to talk about why I think it’s such an important study.

   A multi-national team of researchers has applied a new genomic tool to a 50-year-old bacterial foe, using minute mutations to track the spread of drug-resistant staph both across continents and within a single hospital.
   On a global scale, their sleuthing tracked the movement of one clone of methicillin-resistant Staphylococcus aureus (MRSA) back and forth across the planet, pinpointing when individual cases transported infections across national borders to spark new outbreaks. Separately, their method demonstrated that what appeared to be a hospital epidemic of MRSA was not a single outbreak, but rather a mixed event of patient-to-patient transmission of one strain that was accompanied by multiple importations from outside the hospital of similar but unrelated strains. …
   In a briefing yesterday for the press, the authors emphasized the latter finding, pointing out that the traditional infection control measures usually applied to hospital outbreaks would not curb the spread of infections that were carried in undetected from outside. Their method, they said, provides a proof of concept for using cutting-edge genomics to uncover the precise pathways by which MRSA spreads within hospitals—not only tracing its path from patient to patient, but also identifying the bug in patients whose undetected bacterial carriage could spark outbreaks but have not yet.

 If you’d like more, here’s a very good story at Scientific American, one at BBC Health and one by the Associated Press; and Science Daily‘s version.

Now, the details. This team (which has 15 members from almost as many institutions) secured two collections of MRSA isolates: 43 collected from all over the globe between 1982 and 2003, and 20 from a single hospital in Thailand, collected between October 2006 and November 2007. All of the isolates were ST239, which is a hospital-acquired strain that is particularly prevalent in Asia. They analyzed them using high-throughput sequencing, with a particular analyzer (Illumina) that could produce whole genomes of up to 96 isolates very quickly (an extraordinary advance from the weeks and months it used to take to achieve a single whole genome). Then they compared the genomes, looking for single-letter changes in the genetic code (single-nucleotide polymorphisms, SNPs or “snips,” and also insertions and deletions of nucleotides). They used those findings to construct a “family tree” of 239 that tracks very nicely with the known history of MRSA’s emergence and initial spread, and that pinpoints rare but intriguing importations of clones from certain areas into other parts of the world.

But it’s what they found in the Thai hospital isolates that is especially interesting. (Most of this is not explicit in the paper, but was related in the press briefing that Science conducted on Wednesday). The differences that can be seen in the whole-genome analysis can’t be discerned by earlier identification methods, so the isolates collected at the hospital appeared to be the same. However, they weren’t the same. Some of them were very closely related, and formed what seems to have been a chain of person-to-person transmission — a true hospital-acquired outbreak. But others of them were not so closely related, either to the outbreak or to each other. What they were, instead, were individual importations into the hospital of a hospital strain that had been acquired outside the hospital, and were carried in by staff, patients, visitors.

You can see where this is going, right? If all the cases in the hospital had represented patient to patient transmission within a known outbreak, excellent infection control might have corralled them. But some of them were not part of that outbreak, so infection control measures aimed at that outbreak would not have kept those other cases from spreading. What would have stopped them from spreading, as the authors pointed out, is detecting them at some other point in their entry into the hospital:

…”That implies you have to have a different perspective on where you are going to apply your infection-control procedures and strategies,” co-author Dr. Sharon Peacock of the University of Cambridge said during the briefing.

What that sounds like — and the authors acknowledged as much — is an argument for active detection and isolation/active surveillance and testing/search and destroy, the process of screening some percentage of patients coming into a hospital for MRSA carriage so that the bug can be detected and dealt with long before its presence triggers an outbreak. It is probably not a coincidence that the majority of the authors (including Peacock) are British, and search and destroy has recently become widely accepted in the UK; in fact, the National Health Service recently made it mandatory.

But search and destroy remains remarkably controversial here in the US, despite strong proof of concept demonstrations in healthcare institutions such as Evanston-Northwestern Healthcare, and adoption throughout the VA system. I’ll be interested to see whether this paper makes a dent in the overall resistance to search and destroy, and if not, to hear why not.

The cite is: Harris SR, Feil EJ, Holden MTG, et al. Evolution of MRSA during hospital transmission and intercontinental spread. Science 2010 Jan 22;327(5964):469-74

One surgical infection with MRSA: $61,000

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From a multi-state, public-private research team — Duke University, Wayne State University, and the Durham, NC VA — comes a precise and alarming calculation of MRSA’s costs in hospitals: For one post-surgery infection, $61,681.

The group compared the course, costs and final outcome of three matched groups of patients from one tertiary-care center and six community hospitals in one infection-control network run by Duke. The three groups were: patients with a MRSA surgical-site infection; patients with a surgical-site infection (SSI) due to MSSA, drug-sensitive staph; and surgery patients who did not experience infections, matched to the other two groups by hospital, type of procedure, and year when the procedure took place. (This same cohort has been described in an earlier prospective study that looked at risks for MRSA SSIs.) Altogether, there were 150 patients with MRSA SSIs, 128 with MSSA SSIs, and 231 uninfected surgery patients to serve as controls.

Here’s what they found. Patients with post-surgical MRSA infections:

  • stayed in the hospital 23 days longer
  • incurred an average extra cost of $61,681
  • were more likely to be readmitted to the hospital within 90 days
  • were more likely to die before 90 days had passed.

The authors write:

Our study represents the largest study to date of outcomes due to SSI due to MRSA. Our findings confirm that SSIs due to MRSA lead to significant patient suffering and provide quantitative estimates of the staggering costs of these infections. SSI due to MRSA led to a 7-fold increased risk of death, a 35-fold increased risk of hospital readmission, more than 3 weeks of additional hospitalization, and more than $60,000 of additional charges compared to uninfected controls.

For just the patients in this study, the excess costs (across 7 hospitals) totalled $19 million.

This is a highly useful study on several axes. First, remarkably, there has not been agreement over whether and how much of a problem MRSA poses in post-surgical settings, particularly when compared to drug-sensitive staph. This study provides careful, thoughtful, well-documented proof that combating MRSA infection is worthwhile. (NB, MRSA infections did not increase the risk of death relative to MSSA infections, which should remind us both of the often-forgotten virulence of MSSA, and also that MRSA’s perils can lie in extended illness and disability as much or more as in early death.) Second, by putting a very specific number on the cost of a post-surgical MRSA infection, it gives healthcare administrators a benchmark against which they can judge the cost of a prevention program. We’ve all heard complaints that prevention programs can be costly and their benefit is hard to measure in a bottom-line way. With this very specific number, that complaint should no longer be valid.

There’s a final point that is implied in the paper but not called out, so let me call it out on the authors’ behalf. These results are very likely an under-estimate of MRSA’s costs. That’s because, first, the specific procedures the patients underwent were cardiothoracic and orthopedic; those are not the surgical procedures most likely to be followed by a MRSA infection. And second, data collection for this study ceased in 2003, about a year after the first emergence of USA300 and several years before that very successful community strain began its current move into hospitals. However much MRSA was extant in 2003, there is more now.

The cite is: Anderson DJ, Kaye KS, Chen LF, Schmader KE, Choi Y, et al. 2009 Clinical and Financial Outcomes Due to Methicillin Resistant Staphylococcus aureus Surgical Site Infection: A Multi-Center Matched Outcomes Study. PLoS ONE 4(12): e8305. doi:10.1371/journal.pone.0008305

Bad news from California: MRSA quadrupled

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Via the Fresno Business Journal and the Torrance Daily Breeze come reports of a new study by California’s Office of Statewide Health Planning and Development: Known MRSA cases in the state’s hospitals increased four-fold between 1999 and 2007, from 13,000 to 52,000 cases per year.

From the Torrance paper:

The good news is that the percentage of people who die of MRSA has decreased, from about 35 percent in 1999 to 24 percent in 2007. The raw number of deaths, however, more than doubled to about 12,500. (Byline: Melissa Evans)

From the Fresno paper (no byline):

Fresno, Kings, Madera and Tulare counties were among 38 counties in California that had 61 to 80% of patients with staph infections.
Only one county, Sierra, fared worse. Eight-one to 100% of patients ended up with staph infections in that county’s hospitals.
In 1999, Kings and Madera counties were in the 0 to 20% range and Fresno and Tulare counties were in the 21 to 40% range.

100%??



Community MRSA rates rising, and epidemics converging

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A study published Tuesday in Emerging Infectious Diseases makes me happy, despite its grim import, because it confirms something that I will say in SUPERBUG: Community MRSA strains are moving into hospitals, blurring the lines between the two epidemics.

The study is by researchers at the excellent Extending the Cure project of Resources for the Future, a group that focuses on applying rational economic analysis (think Freakonomics) to the problem of reducing inappropriate antibiotic use. (Here’s a post from last year about their work.)

Briefly, the researchers used a nationally representative, commercial (that is, not federal) database of isolates submitted to clinical microbiology labs, separated out MRSA isolates, divided them into whether they originated from hospitals or outpatient settings (doctors’ offices, ambulatory surgery centers, ERs), and analysed them by resistance profile, which has been a good (thogh not perfect) indicator of whether strains are hospital or community types (HA-MRSA or CA-MRSA). They cut the data several different ways and found:

  • Between 1999 and 2006, the percentage of staph isolates from outpatient settings that were MRSA almost doubled, increasing 10% every year and ending up at 52.9%. Among inpatients, the increase was 25%, from 46.7% to 58.5%.
  • Among outpatients, the proportion of MRSA isolates that were CA-MRSA increased 7-fold, going from 3.6% of all MRSA to 28.2%. Among inpatients, CA-MRSA also increased 7-fold, going from 3.3% of MRSA isolates to 19.8%.
  • Over those 7 years, HA-MRSA did not significantly decrease, indicating that CA-MRSA infections are not replacing HA-MRSA, but adding to the overall epidemic.

So what does this mean? There are a number of significant aspects — let’s say, bad news, good news, bad news.

Bad: CA-MRSA strains are entering hospitals in an undetected manner. That could simply be because patients entering the hospital are colonized by the bug and carry it with them. But it could also be because healthcare staff who move back and forth between outpatient and in-patient settings — say, an ambulatory surgical center and a med-surg ward — could be carrying the bug with them as well.

Good: If they are detected (analyzed genotypically or for drug sensitivity), CA-MRSA strains are less expensive to treat because they are resistant to fewer drugs, and some of the drugs to which they are susceptible are older generics, meaning that they are cheaper.

Very Bad: The entrance of CA-MRSA strains into hospitals risks the trading of resistance factors and genetic determinants of transmissibility and colonization aptitude in a setting where bacteria are under great selective pressure. Several research teams have already seen this: In several parts of the country, CA-MRSA strains have become resistant to multiple drug families.

Is there a response? The work of Extending the Cure focuses on developing incentives that will drive changes in behavior around antibiotic use. These results, lead author Eili Klein told me, call for developing incentives for creating rapid diagnostic tests that will identify not just that a bug is MRSA, but what strain it is, so that it can be treated appropriately and not overtreated.

The results also underline the need for something that is particularly important to me: enhanced, appropriately funded surveillance that will define the true size of the MRSA epidemic and delineate the behavior of the various strains within it. Right now, surveillance is patchy and incomplete, done partially by various CDC initiatives and partially by the major MRSA research teams at academic medical centers. As we’ve discussed, there is no national requirement for surveillance of patients, and very few state requirements; there is no incentive for insurance companies to pay for surveillance, since it benefits public health, not the patient whose treatment the insurance is paying for; and there is a strong disincentive for hospitals to disclose surveillance results, because they will be tarred as dirty or problematic. Yet to know what to do about the MRSA epidemic, we first have to know the size and character of what we are dealing with, and we do not now.

The cite is: Klein E, Smith DL, Laxminarayan R. Community-associated methicillin-resistant Staphylococcus aureus in outpatients, United States, 1999–2006. Emerg Infect Dis. DOI: 10.3201/eid1512.081341

Antibiotic-resistant infections: millions in cost to hospitals, families, all of us

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Folks, I mentioned that I’m way behind in working down a stack of great articles. Here’s a very good one that I missed when it came out two weeks ago and is well worth your time.

A team from John H. Stroger Hospital (the new location of the iconic Cook County Hospital, public hospital for downtown Chicago) and from the Alliance for the Prudent Use of Antibiotics at Tufts University (headed by Dr. Stuart Levy, dean of antibiotic resistance scholarship in the US) has analyzed the direct and distributed costs of resistant infections, and their results are stunning. They took a random sample of patients seen at the hospital, sorted out a subgroup that suffered from resistant infections, and computed the costs that those infections imposed: in medical costs, increased length of stay, and excess deaths. Those sort of calculations have been done before at other institutions (cf. for instance the excellent work of Susan Cosgrove of Johns Hopkins), but what makes this Chicago study striking is an additional layer of analysis that computes the “social cost” to the families of those infected.

In the study’s words:

In a sample of 1391 patients, 188 (13.5%) had [antibiotic-resistant infections]. The medical costs attributable to ARI ranged from $18,588 to $29,069 per patient in the sensitivity analysis. Excess duration of hospital stay was 6.4–12.7 days, and attributable mortality was 6.5%. The societal costs were $10.7–$15.0 million.

(Just to underline: These are almost certainly underestimates of the current problem and its current costs — because to get very solid data, the Stroger team went back in their database to patients who were treated in 2000. That’s before the emergence and dominance of CA-MRSA USA300 nationwide, and its subsequent movement into hospitals. Since 2000, the MRSA epidemic has gotten worse.)

An accompanying editorial takes the next step in logic, stressing that if we’re not going to work to reduce ARIs because it is good medicine to do so, we should do it because it is critically cost-saving:

…[T]he findings of Roberts et al [11] are significant, making a strong case for both the medical and financial benefits of reducing antimicrobial resistance. This is an important and timely question, considering the national focus on the prevention of health care–acquired infections, a significant proportion of which are caused by antimicrobial-resistant organisms, and the call for institutions to develop antimicrobial stewardship programs. These data should help inform decisions regarding the structure and implementation of health care initiatives designed to improve patient care while controlling unnecessary costs.

The cite for the study is: Rebecca R. Roberts, Bala Hota, Ibrar Ahmad et al. Hospital and Societal Costs of Antimicrobial‐Resistant Infections in a Chicago Teaching Hospital: Implications for Antibiotic Stewardship. Clinical Infectious Diseases 2009 49:8, 1175-1184.