One more on MRSA in meat

It turns out that European governments — in contrast to the United States — are taking very seriously the emergence of MRSA in food animals and its potential for transfer to humans. (For background, posts here, here, here and here.)

How seriously? They're doing a sampling survey of pigs on farms across the European Union, at a cost of about $3 million in EC funds, with matching funds expected from each government.

The MRSA survey piggybacks (sorry) on a year-long survey of Salmonella incidence that the EC called for in September 2007. But in December, following publication of several significant papers about the ST 398 MRSA strain in pigs and pig farmers, the EC Directorate-General for Health and Consumer Protection pushed for an addition to the Salmonella study: a same-time sampling for the presence of MRSA strains in pig operations across 29 countries.

The sampling is taking place from January to December of this year, with results mandated by mid-2009, though individual country authorities may release data earlier if they choose. (In the wake of the finding of three ST 398 cases apparently caused by retail meat in the UK, the Soil Association has called on the British government to release whatever data it has ASAP. Before the EC decision, the UK government had refused to test its pigs; cf. these House of Lords minutes.)

Of note: The Soil Association is pressing the argument that ST 398 has developed in the setting of widespread use of antibiotics in food animals, and contends the strain's arising in the Netherlands is especially alarming because they have some of the lowest animal-antibiotic use rates in the EC it illustrates the difficulties that even a society conscientious about antibiotic overuse can have keeping track of veterinary applications. The Netherlands has been successful limiting overuse in humans, but has found controlling veterinary use much more of a struggle. (Thanks to the Soil Association for correcting my misunderstanding!)

MRSA in the food chain?

Behind the growing number of findings of MRSA in food animals and the humans who work with them — in the Netherlands, Canada and now in the US — there lurks a persistent concern that the meat of those animals could be a vector for MRSA transmission. Dr. J Scott Weese of the Ontario Veterinary College raised the possibility in a presentation I reported on at the International Conference on Emerging Infectious Diseases, and Dutch researchers raised it in a paper last year as well.

Until now, though, it has been a hypothetical concern, since the humans found with pig-associated MRSA (both the already-recognized community and hospital strains and the emerging ST 398 strain) have all been animal workers.

So much for hypothesis. The London newspaper The Independent is reporting that the ST 398 strain has sickened three patients in Scotland who have no connection to animal raising or slaughtering, suggesting their infections came from contact with raw meat.

All three patients, who were being treated in at least two different Scottish hospitals, recovered. Confirming the cases, Dr Giles Edwards, director of the Scottish MRSA Reference Laboratory, said: "A lot of the patients who got this infection in Holland and Canada have been people who work with animals, such as farmers and vets. But none of the three individuals in Scotland have been in contact with animals, not that we could find." (Byline: Martin Hickman)

The bug has not currently been found in pigs raised in England, but about two-thirds of pork sold in the UK is actually imported from the Netherlands. So the Soil Association (the British farming lobby) has asked the government to begin testing imported pork for MRSA strains. The British Food Standards Agency disagrees, however, telling the Independent it does not "see serious food safety issues."

Which is strikingly close to what CDC Director Dr. Julie Gerberding said in February when asked by the House Committee on Agriculture about the Dutch and Canadian reports:

... although the finding of MRSA in retail meats suggests a possible role for foodborne transmission, if such transmission occurs, it likely accounts for a very small proportion of human infections in the United States. (Letter .pdf archived here on the site of the National Pork Producers Council.)

Hmmm.

UPDATE: The Soil Association's statement, with some good additional references (including to a newspaper report by the Sunday Post two days before the Independent's) is here. More to come on this, I think.

Much more on MRSA and animals

Again from the 108th General Meeting of the American Society for Microbiology: new findings on the complex interaction of MRSA in humans, pets and food animals.

• From the University of Iowa, the first finding of MRSA in US pigs, on seven farms in Iowa and Illinois. The abstract doesn't say what subtype of MRSA was found, but a new strain of MRSA was found last year in pigs in the Netherlands and both that strain and a known human strain have been found in pigs in Canada. Carriage rates among the Midwestern pigs: from 100% of very young animals to 36% among adult swine. (Poster 983, first author AL Harper)
• From Nicholls State University and two veterinary practices in southern Louisiana, results of screening tests on pets show high rates of carriage of methicillin-resistant Staph species. The pets carried both S. aureus and S. intermedius. (Poster 1017, first author T. Rachal.) For an earlier post on pets harboring MRSA, look here.
• And from the University of Georgia, an analysis of MRSA strains isolated from 50 humans and 60 companion animals (dogs, cats, horses, birds) found the same strains in both: SCCmec type II, a hospital strain, and SCCmec type IV, the main community strain. Human carriage rates: 78% type IV, 22% type II. Animal carriage rates: overall, 40% type IV and 60% type II, but with some important differences between species — all of the cats and birds harbored type II, while the dog isolates were overwhelmingly II and the horses overwhelmingly IV. Of greatest importance, the types did not have identical resistance patterns: In humans, the type IV was sensitive to vancomycin and tetracycline, but the animal IV was sensitive to vanco only, suggesting that MRSA may be evolving differently in its transient animal hosts — an especial concern if the animal-carried strains pass back to humans. (Poster 1027, first author S. Sanchez.)

Antibacterial wipes - as reliable as they seem?

The general meeting of the American Society for Microbiology is taking place in Boston this week, and the agenda is rich with papers on MRSA. Here is one from today, with interesting and dismaying news.

A team from the Welsh School of Pharmacy at Cardiff University tested the killing efficacy of premoistened antibacterial wipes used to decontaminate surfaces in hospitals. No brand is specified in the abstract, but they are described as "commercially available wipes containing either disinfectant, detergent or natural antimicrobial" that are called for in the "disinfection regimens adopted in [intensive care units] in the UK."

The team, led by Dr. Gareth Williams and funded by the Wales Office of Research and Development for Health and Social Care, devised a three-step protocol to test the ability of the wipes to remove, kill, and prevent transfer of Staph aureus and MRSA from surfaces. To guarantee consistency and replicability, the protocol included the use of a device that mechanically rotated the wipes against contaminated surfaces at a particular pressure (100 grams +/- 5) and speed (60 rpm).

And the results are: not so great. The wipes did remove bacteria, but did not kill them. When the used wipes were pressed against agar plates, the plates grew bacterial colonies, raising the possibility that the wipes would transfer viable bacteria between surfaces in real-world use. The team's conclusion:

We recommend that a wipe is not to be used on consecutive surfaces, but only on a small area and discarded immediately after use.

The cite is: Determining the Ability of Surface Wipes to Remove, Kill and Prevent the Transfer of Staphylococcus aureus from Contaminated Surfaces. GJ Williams, SP Denyer, IK Hosein, DW Hill and JY Maillard. Poster 860, 108th General Meeting ASM.

(By the way, I am posting this using Blogger's new post-date utility. If it works, this post should magically appear at 1p EDT on 3 June. If it shows up early, someone will have some splaining to do.)

Studies: gator blood, sudden infant death syndrome

I blogged earlier on new research that alligator blood may contain potent antimicrobial compounds. Now the Miami Herald has done a nice long story that thoughtfully explores the possibilities and limitations of that research. (Hat tip to KSJ ScienceTracker for noting the story.)

And via the BBC, here is a report that British researchers believe some vases of Sudden Infant Death Syndrome (which the English call " sudden unexpected death in infancy (SUDI)") may be due to undetected bacterial infections.

The researchers took samples from 470 babies who had died suddenly, and tested them for the presence of bacteria, particularly those capable of causing illness, such as Staphylococcus aureus or E. coli.
In some cases, the cause of death was known to be a bacterial infection, or completely unrelated to infection, for example a heart defect or accident. The rest were entirely unexplained.
Among those known to have died from a bacterial infection, 24% of the bacteria found were potentially harmful, compared with only 11% of those found in the non-infection group.
However, among the "unexplained" group, the figure was 19%, with 16% of bacteria found in this group identified as Staphylococcus, compared with 9% in the non-infection group. (Emphasis added.)

The authors theorize that toxins produced by staph could interfere with breathing or affect the nervous system. The paper, just published by The Lancet, is here and a Lancet-produced podcast (.mp3) is here.

Hospital gives patient MRSA. Should Medicare reimburse?

You have until June 13th to tell the government what you think. Details of how to comment at the end of this post because they are complicated.

Here's the back-story: Until recently, hospitals were reimbursed by the Center for Medicare and Medicaid Services (part of the US Department of Health and Human Services) whenever they provided care to Medicare or Medicaid patients, even if that care included a mistake, error or hospital-acquired infection. Thankfully, that is beginning to change. Last December, CMS proposed a rule change. In the agency's language:

Beginning October 1, 2008, Medicare will no longer pay hospitals at a higher rate for the increased costs of care that result when a patient is harmed by one of several conditions they didn’t have when they were first admitted to the hospital and that have been determined to be reasonably preventable by following generally accepted guidelines. (Quoted from this press release.)

In other words: Hospitals, you break it, you bought it.

These are the conditions for which, as of Oct. 1, 2008 (the first day of federal fiscal year 2009), Medicare will not reimburse:

• Object inadvertently left in after surgery
• Air embolism
• Blood incompatibility
• Catheter associated urinary tract infection
• Pressure ulcer (decubitus ulcer)
• Vascular catheter associated infection
• Surgical site infection - Mediastinitis (infection in the chest) after coronary artery bypass graft surgery
• Certain types of falls and trauma.

Note: MRSA is not on that list. But: At the same time, CMS proposed a second set of error-related conditions for which it will consider not-reimbursing, based on public comment. Some of those conditions are MRSA-related. The conditions are:

• Surgical site infections following certain elective procedures.
• Legionnaires’ disease (a type of pneumonia caused by a specific bacterium)
• Extreme blood sugar derangement
• Iatrogenic pneumothorax (collapse of the lung)
• Delirium
• Ventilator-associated pneumonia
• Deep vein thrombosis/Pulmonary Embolism (formation/movement of a blood clot)
• Staphylococcus aureus septicemia (bloodstream infection)
• Clostridium difficile associated disease (a bacterium that causes severe diarrhea and more serious intestinal conditions such as colitis)

CMS will decide whether or not to include any or all of those additional events by Aug. 1. The non-reimbursement would start at a later date that the first list.

This a complex topic and there is a long paper trail attached to it. Fact sheets are here. Definitions of the conditions, as accepted by CMS and the CDC, are here. The records of the Dec. 17. 2007 hearing in which this was discussed, including complete transcripts, is here.

Directions for how to comment electronically and by mail and hand-delivery (faxes are not accepted) are contained in this long Federal Register entry. Here is how to do it electronically:

• Go to http://www.regulations.gov
• Under "Comment or Submission," enter this file-code: CMS–1390–P
• Click on "Send a comment or submission" in the left-middle of the page.
• Fill out the form that comes up (you may have to page-down to see the full form).

Rumors of the blog's death are only slightly exaggerated (3d ed.)

Apologies for the non-appearance: I am deep into writing (and also continuing research travel) and it's hard to carve out the extra hour a day. But here is something new that is worth posting on. Jeanine Thomas, MRSA patient and prominent activist, has put up a site, blog and online community for MRSA stories and activism. Thomas, who lives in Chicago, contracted and almost died from a MRSA infection following ankle surgery in 2000 and went on to lead one of the first successful efforts to enact state legislation for MRSA control.

Find the MRSA Survivors Network in the blogroll and here.