Maryn McKenna

Journalist and Author

More on NDM-1

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One of the frustrations of being a working journalist and a blogger is that, when a big blog-story breaks, you’re likely already to be working on something else. And so it is, unfortunately, with NDM-1: I’m on a magazine assignment and will be off interviewing people when I should be blogging.

(This s a great time to recommend that, for any breaking infectious disease news, you follow Crof at H5N1 (@crof) and Michael Coston at Avian Flu Diary (@Fla_Medic), who are dedicated, thoughtful, nimble and smart.)

Since I last posted, there’s been lots of additional coverage of the “Indian superbug.” Much of it, blog and media, is just echo chamber cannibalizing of the earliest reports (including but certainly not only mine), but there are some important new developments worth noting, which I’ll list below.

There are also some important points that are getting lost in the echo-chamber bounce: First, it is not correct to say that every person who acquired this was seeking cheap medical care or engaged in medical tourism; a few of them were treated on an emergency basis while traveling, and a few have no apparent healthcare tie. So this is not a situation of people seeking to save money and, as some commenters seem to be suggesting, receiving their karmic payback. (C’mon: Seriously?) Second, it is also not correct to say that every case of this has been linked to a hospital — it’s quite clear in the Lancet ID paper that in South Asia, a number of the cases were community infections. So it is not just a case of hospitals that are dirty or have poor infection control (which by the way is a problem in the US as well, right?); NDM-1 is already a community bug, which will make detection and defense much more complex.

OK, curated list:

First, if you’re interested in more from me, CNBC asked me to write up a piece about NDM-1, which ran Thursday; and Friday morning I was on the WNYC-FM (and nationally syndicated) radio show The Takeaway.

Second, the list of potential victims of NDM-1 is growing. Most of them have survived, so marking their cases is really a way of measuring the resistance factor’s previously undetected spread:

The UK has released a new statement, updating its earlier warning, and says it has found “around 50” cases carrying NDM-1, an update from the Lancet ID paper. (Side note: This statement, and the earlier warnings, came from the UK’s Health Protection Agency. The UK has just announced that it will be shutting down that agency in a cost-cutting measure. Great timing.)

The government of Hong Kong has announced that it has seen one case of NDM-1, but the patient recovered.

Canada has disclosed that it has had two cases, not the one mentioned in the Lancet ID editorial, in two different provinces.

Australia says that it has had three cases scattered across the country.

Belgium has announced one death.

And finally — sadly but probably not surprisingly — India is objecting to the stigma of being characterized as the source of NDM-1. The study’s first author has disassociated himself from the paper and members of the government are claiming a “pharma conspiracy.” Medical tourism has become a significant industry in India, and it is true  some of these reports cast doubt on its safety. But still, I find this reaction disappointing.

Evading the stigma of an emerging disease is not a new impulse: Recall how the government of China suppressed for 6 months the news of the start of the SARS epidemic. They did not stop the epidemic, of course — it eventually sicked more than 8000 people across the globe and killed about 775 — but their suppression of the details of its spread kept other jurisdictions from mounting a defense in time. From my teaching gigs in Hong Kong I can testify how much bitterness endures in Hong Kong over this.

China’s actions in 2002-03 led to the enactment of the new International Health Regulations by the WHO, which specify that, because expanding epidemics take no notice of borders, it is inappropriate for any government to attempt to impede the free flow of information about their spread. India is a signatory to the IHRs.

I am not suggesting that India is attempting any suppression of news about NDM-1 — there’s no evidence of that — but the volatile language being used does concern me. I acknowledge that India is an extremely open society, with degrees of political expression that can sound surprising from this distance. But let’s hope the government takes its commitment to the IHRs as seriously as any signatory should.

“Pig MRSA” causing human infections

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Hi, everyone. Apologies for dropping out of sight! As SUPERBUG’s publication draws closer (and it’s very close now), I keep finding new tasks that I have do to. Last week’s was to go to New York to shoot a video for the Simon & Schuster website — and while there, I got caught in Snowpocalypse, got delayed coming home, and picked up a nasty cold. So I’m a bit behind.

But there’s exciting news tonight to start us up again: “pig MRSA,” ST398, causing human infections in Canada and Denmark.

“Infections” is important, because up til now, most evidence for  the spread of MRSA ST398 in humans has been through detection of colonization, the symptomless carriage of MRSA on the skin and in the nostrils. The first finding of ST398 in the Netherlands was via colonization; so was its first identification in humans in Canada, and also in the United States just about a year ago.

But comes now a team of public and university scientists from Canada to say that ST398 is also causing infections in Canada. They analyzed 3,687 MRSA isolates that had been collected from patients seen for infections in Manitoba and Saskatchewan. Five were ST398. That is an exceedingly low percentage, of course. But it is striking, and odd, that the infections were present at all:

The earliest identified LA-MRSA isolate (08 BA 2176) associated with an infection was obtained from a postoperative surgical site. … This patient is unlikely to have had any recent direct contact with livestock because she had been confined to her home with limited mobility for several years before her hospitalization. Additional nasal swabs from this patient remained positive for this strain for at least 7 months. …
The isolate submitted to the NML by Sunnybrook Health Sciences Centre… was from a 59-year-old man from Ontario. He had been hospitalized in December 2007 for treatment of metastatic squamous cell carcinoma of the larynx. In the previous year, he had undergone a total laryngectomy, neck node dissection, and tracheostomy. …. He was unaware of any animal contact and had no history of exposure to pigs or pig farms. A review of the medical records and standard epidemiologic investigations determined that this was not a nosocomial or healthcare-associated isolate.

Just to underline, we have here a MRSA strain that is strongly associated with close contact with pigs, or with pig meat, and that has spread far enough from farms to be present in people who had no connection with pigs. You can argue that its very low prevalence means that it is not so much a threat as a curiosity. But I’d counter-argue that this is significant: because it establishes that this strain is spreading; because it demonstrates that the strain is causing infections, not just colonization; and because it inserts, into the swarm of isolates that make up MRSA, additional resistance factors that can be traded and exchanged unpredictably among the bacteria — and are likely not to be detected because our surveillance in animals is so sparse.

The authors say:

…additional surveillance efforts are required to monitor the emergence and clinical relevance of this MRSA strain in Canada, including communities, the environment, livestock, farmers, and production facility workers. Whether these strains pose a major threat to human health in light of the low livestock density and continued spread of epidemic hospital and community strains of MRSA in Canada remains unknown.

There’s also a new and tantalizing report from Denmark that appears to describe not only human infections, but human to human transmission, resulting in a very serious pneumonia in a baby. I can’t access the full-text even through my university account, but the abstract says:

Carriage of pig-associated methicillin-resistant Staphylococcus aureus (MRSA) is known to occur in pig farmers. Zoonotic lineages of MRSA have been considered of low virulence and with limited capacity for inter-human spread. We present a case of family transmission of pig-associated MRSA ST398, which resulted in a severe infection in a newborn.

Not good.

The cites for these are:
Golding GR, Bryden L, Levett PN, McDonald RR, Wong A, Wylie J, et al. Livestock-associated methicillin-resistant Staphylococcus aureus sequence type 398 in humans, Canada. Emerg Infect Dis; [Epub ahead of print] DOI: 10.3201/eid1604.091435
Hartmeyer GN, Gahrn-Hansen B, Skov RL, Kolmos HJ. Pig-associated methicillin-resistant Staphylococcus aureus: Family transmission and severe pneumonia in a newborn. Scand J Inf Dis. Epub Feb. 3, 2010 ahead of print.

Antibiotics in chickens and links to human infections

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From the January issue of Emerging Infectious Diseases, published by the CDC (and therefore free. Must I keep urging you to read it? Go, already), here’s a roundup of bad news about bad bugs.

In Canada, researchers from that country’s Public Health Agency have found a “strong correlation” between the use of ceftiofur, a third-generation cephalosporin, in chickens; the rates of a resistant strain of Salmonella in chickens; and the appearance of that same strain in humans. The strain is Salmonella enterica serovar Heidelberg, one of the most common salmonella strains in North America, and one which can be nasty: It may cause mild illness, but also causes septicemia and myocarditis and can kill. Quebec created an unplanned natural experiment: Hatcheries there were broadly using ceftiofur until 2004, backed off from its use in 2005 and 2006, and then began using it again in 2007 in response to a growing problem with a particular infection. When the drug was withdrawn, resistant infections in birds and humans plunged; when it was reintroduced, they rose again. (Look at the black and red lines in the graph above left.)

Meanwhile, broiler chickens in Iceland are passing fluoroquinolone-resistant E. coli to humans there. Researchers at the University of Iceland were puzzled by an earlier finding that bacteria resistant to fluoroquinolones (a family that includes the human drug Cipro) were increasing among chickens raised in Iceland, despite strict controls on antibiotic use in food animals and stringent disinfection in chicken batteries after cohorts of birds were sold for slaughter and removed. They have two findings: The source of the resistant bacteria in the birds appears to be feed contaminated with resistant E. coli; and resistant bacteria in Iceland residents are microbiologically indistinguishable from those in the birds. Because E. coli is a very diverse organism, the very close resemblance between the isolates from chickens and the isolates from humans pins chickens as the likely source.

And just to make clear we’re not blaming every microbiological evil on farming: Seagulls in Portugal have been found carrying multi-drug resistant E. coli in their feces. The public health concern here is obvious: Just think back to the last time you were at a beach, or anywhere else seagulls frequent, and envision a seagull perch — and the masses of seagull droppings streaking it. Now imagine those droppings transmitting antibiotic-resistant E. coli into the surrounding environment: the boardwalk, the beach, the towels… Additional problem: Seagulls are migratory birds, so the resistant bacteria easily cross borders and oceans.

Restricting antibiotics in animals: Start by restricting access

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Constant readers, those of you who follow the pressing issue of MRSA in animals will know the work of J. Scott Weese, DVS, associate professor of pathobiology at the University of Guelph in Ontario and supervising author of many crucial papers on MRSA in food and companion animals, including the first finding of MRSA in pigs and pig farmers in North America.

You may not know that Weese and his postdoc Maureen Anderson publish an excellent blog on veterinary and zoonotic diseases called Worms and Germs (in the blogroll at right). This weekend they have an important post that deserves wider attention: Antibiotics: A Dose of Common Sense. In it, they propose that one way to reduce the overuse of drugs in food animals is to make animal antibiotics prescription-only. It’s worth taking the time to read it.

Those of you in the cities may not know this, but out here in the Great Flyover, antibiotics for veterinary use are surprisingly easy to buy (as I discovered when I stumbled into a farm-related store in search of a Carhartt jacket against the Minnesota winter). They’re not even over-the-counter — they’re on the shelf, or stacked on the floor with the implements and feed, or blended into the feed itself. And as Weese points out in this post, they are also available without prescription over the Internet (as human antibiotics are too).

It’s a potentially controversial proposal: I don’t think I have any farming readers, but I would imagine their response would start with an objection to the extra cost of hiring a veterinarian to assess whatever situation might require the drugs. And since most farmers (NB: not the overarching ag-biz companies, but the farmers themselves) exist on razor-thin economic margins, they would have a point. But as we know from the excellent work of Extending the Cure and the Center for a Livable Future, unnecessary antibiotic use comes with a cost as well — one that is borne by all of us when antimicrobial resistance prevents antibiotics from working.

Did MRSA kill an Ontario nurse?

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Here is a story that was flagged by several commenters (welcome, Canadian readers), and is being reported by a number of Canadian news outlets: A nurse who worked in the critical care unit at Victoria Hospital in London, Ont. has died, possibly of MRSA, and the Ontario Ministry of Labor is investigating whether her death is an occupational exposure — that is, whether she caught the bug in the process of working in the hospital.

There’s not a lot of detail in the stories published so far. The St. Thomas (Ont.) Times-Journal, the London (Ont.) Free Press and the Canadian Press suggest that the nurse was a patient in her own hospital and acquired the infection while a patient. The Toronto Globe and Mail, on the other hand, casts the story as the nurse working, becoming sick, and then becoming a patient.

Occupational infections with MRSA have certainly been recorded. A Texas firefighter and EMT died of invasive MRSA in 2006, and his widow alleged it was because of his exposure to MRSA patients; an Illinois EMT almost lost a leg to the infection in 2007.

Let’s stipulate that this Ontario nurse’s death is terribly sad. The question will be whether it is also scientifically confounding. A hospital is going to have a substantial background rate of MRSA, in infected patients, colonized patients and colonized personnel. If her death turns out to be caused by MRSA, it will be important to ascertain both the timeline — did she become sick while working, or while undergoing care for some other health problem — and also the microbiology: Did she have whatever strain is predominant in her hospital? Or was it on the other hand a strain that is circulating in the community (provided that community strains have not moved into hospitals in Ontario as they have in the US)?

That sort of microbiological differentiation provided an important clue in the death of Maribel Espada, a British nurse who died of invasive MRSA in 2006, six days after giving birth at the hospital where she worked. Unusually for the UK, Espada was infected with a PVL+ strain of MRSA, something that is very common in US community strains, but unusual in the UK until recently. That allowed her infection to stand out from the background, and suggested that she had been infected by a patient in her hospital:

The Health Protection Agency said it was investigating the possibility Mrs Espada caught PVL MRSA from a patient who died at the hospital in March.
A spokesman for University Hospitals of North Staffordshire NHS Trust said all staff who had come in contact with the two people originally diagnosed with PVL MRSA had been screened by the hospital’s infection control team.
A further nine cases were subsequently identified, of which one was a former patient.
The eight other cases were either members of staff or people staff had come into contact with. (BBC News)

“Pig MRSA” in New York City – via the Dominican Republic?

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Folks: Back in October, I broke the news for you of an intriguing poster presentation at the ICAAC meeting. It revealed the discovery of ST 398, the anomalous staph strain found in pigs, pig farmers and health care workers in Europe, in residents of a Dominican-immigrant neighborhood in northern Manhattan, and also in the Dominican Republic.

Because there is so much traffic back and forth between those neighborhoods, the authors theorized that people are providing an “air bridge” for the bacterium — though they were unable to say whether the bug is moving from the Dominican Republic to the United States, or vice versa.

I was unable to link to that presentation at the time, because it was a meeting poster – yes, literally a poster, the authors stand by it to discuss it with anyone who wanders by. However, now it has been published as a paper, in the CDC journal Emerging Infectious Diseases; and because it is a CDC journal, the full text is available free online here.

Just to underline, despite my headline above, the strain found in NYC was not MRSA: It actually is MSSA, drug-sensitive staph. The ST 398 found in Europe, Canada and the American Midwest is MRSA. The authors hypothesize that the NYC strain is at risk of becoming MRSA also.

To see the multiple posts in this blog about MRSA ST 398 and other strains in the food chain, food animals, and pets, go to the labels under the time stamp on this post, and click “animals” or “food.”

The cite for the paper is: Bhat M, Dumortier C, Taylor B, Miller M, Vasquez G, Yunen J, et al. Staphylococcus aureus ST398, New York City and Dominican Republic. Emerg Infect Dis. 2009 Feb; [Epub ahead of print]

Reporting MRSA – a few places see results

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Happy New Year, constant readers. I hope you had relaxing holidays; I myself have been pounding the keyboard, forging through a chapter. (I hope to post pieces at some point, but I need to talk to my editor about when is the right time in the process.)

While I was out, there were a few interesting developments on mandatory reporting of MRSA infections, which we have talked about here, among other posts.

First, the Canadian province of Ontario has launched an amazing website that reports MRSA rates for all its hospitals and allows you to search all its hospitals by name or map location. This is part of an initiative launched last May by the provincial Ministry of Health and Long-term Care that created mandatory reporting for eight indicators of patient safety: C. difficile, MRSA, VRE, standardized mortality rates, ventilator-associated pneumonia, central line infections, surgical site infections, and hand-hygiene compliance. C. diff reporting began in September; MRSA, VRE and mortality rates rolled out on Dec. 30; and the other four will be reported from April 30.

When I look at the very incomplete patchwork of reporting we have achieved state by state in this country, I find the Ontario achievement just stunning.

But, some good news from the US also: Over the holidays, Virginia made its first report of invasive MRSA infections, acting on an emergency order written by Gov. Timothy Kaine following the death of a teen named Ashton Bond in 2007. Strangely, there is no sign of the report on the website of the Virginia Department of Health (if anyone knows where it has been posted, please let me know).[UPDATE: The Virginia DOH very kindly got in touch to say that the numbers are drawn from a set of spreadsheets that are hosted here.] The Virginian-Pilot said:

There were 1,380 invasive MRSA cases reported from Dec. 1, 2007, through the end of this November. The rate for this region of Virginia was 15 per 100,000 people, slightly less than the state rate of 18.
People 60 and older had the highest rate of incidence, and blacks had higher rates than whites. …
Only about 30 percent of the cases reported to the Virginia Health Department listed a known outcome. Of those, there were 35 deaths.
The data do not distinguish between whether MRSA was acquired in a hospital or in the community. The state also doesn’t require reporting of the less serious forms of MRSA that involve skin and tissue infections. (Byline: Elizabeth Simpson)

I especially applaud this caution, attributed to Dr. Christopher Novak, an epidemiologist with the Virginia DOH:

“Just because you’re reporting it doesn’t mean it’s under control.”

File under Unintended Consequences, 1

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My friend and colleague Helen Branswell of the Canadian Press reports (via the Toronto Sun) on the cruel and accidental irony behind an outbreak of healthcare-associated infections at Toronto General Hospital between Dec. 2004 and Mar. 2006. Based on a new paper in Infection Control and Hospital Epidemiology, it’s a fascinating and bizarre tale of the unpredictable hurdles that a hospital can face in attempting to eradicate HAIs.

It seems the hospital, in an attempt to reduce HAIs, installed hand hygiene stations in each room in its medical-surgical intensive care unit, in between the patient’s bed and a countertop that held patient-care materials. This would seem like good design: The sink was right in the middle of the “zone of action” in the room, so health care workers would be reminded to use it (unlike, for instance, retrofitted rooms I have seen where the sink is away from the bed or out of the path between the bed and the door, and where health care workers have to consciously think about using it rather than having it be automatic). And the sinks were of a particular design meant to reduce accidental contamination of health care workers’ hands: When the water was turned on, it flowed from a high gooseneck faucet straight down into the sink drain, without washing around the sink’s side.

But it turns out that design and location both had unanticipated flaws. Water flowing straight into the drain was more likely to splash from the drain back out of the bowl; when investigators marked the sinks with fluorescent dye, they found splashes up to a yard away. Because the sinks were so close to the patient beds, the water was able to contaminate the patients, and the countertops on the other side as well. And because the water was falling directly into the sink drains, without the reduction in velocity caused by allowing it to wash around the sides of the sink, it was able to dislodge biofilm colonies of drug-resistant Pseudomonas aeruginosa, a moisture-loving organism that was growing in the sink pipes — which then splashed out of the sinks in the water bouncing back from the drain.

When the investigators found that, they had an explanation for why 36 transplant patients in that ICU had become colonized with MDR pseudomonas over 18 months. Twenty-four of the patients developed invasive infections, and 17 died; 12 of those deaths were either caused or closely related to pseudomonas infection.

The investigators tried multiple times to decontaminate the sink drains; in a few cases, they were successful, but the drains became recolonized and grew fresh biofilms. It was not practical to relocate the sinks. Nevertheless, they shut down the outbreak: They swapped out the faucets, decreased the water pressure, put a splash barrier on the sides of the sink, and moved patient care materials on the counter next to the sink elsewhere in the ICU rooms. Once those rearrangements were complete, the outbreak stopped.

This outbreak obviously was not MRSA, and in the strictest sense it is not relevant to MRSA, which is not an organism that lives in sink drains. But in a broader sense — as an illustration of the completely unpredictable hurdles that can stand in the way of excellent infection control — it is a useful and tragic cautionary tale.

The abstract is here. The cite is: Susy Hota, MD; Zahir Hirji, MHSc; Karen Stockton, MHSc; et al. Outbreak of Multidrug-Resistant Pseudomonas aeruginosa Colonization and Infection Secondary to Imperfect Intensive Care Unit Room Design. Infection Control and Hospital Epidemiology 2009 30:1, 25-3.

MRSA in newborns on Prince Edward Island: HA? CA? Matters?

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There’s been a running story for several weeks now about the Queen Elizabeth Hospital on Prince Edward Island (home to mussels and Anne of Green Gables). The hospital struggled earlier this year with an outbreak of MRSA and a second outbreak of VRE among adult patients. It got those under control, but since earlier this month has been dealing with a new outbreak of MRSA in its newborn nursery, according to the PEI Guardian:

Nine newborns and one mother have now tested positive for MRSA. Five of those nine cases can be connected to the same source. (Byline: Wayne Thibodeau)

The stories are detailed, for a small paper — they go into depth about the cleaning measures the hospital is taking — and yet they don’t answer the questions that we here want to know. Does “tested positive” mean colonized or infected? Does “connected to the same source” mean they all have the same strain, or does it mean there is an epidemiologic link?

In the latest news (Tuesday’s paper and online edition), the hospital reports that it is doing nasal swabs on more than 300 staff, with the intention to do a 7-day decolonization regimen on anyone who turns up positive. They won’t however, disclose the source when they find it — though, again, it’s not clear whether that means not identifying the staffer (appropriate) or not admitting that it is a nosocomial outbreak (inappropriate and at this stage lacking in credibility):

Rick Adams, CEO of the Queen Elizabeth Hospital, said about 290 staffers have already been screened.
“In terms of the test results, we’re not going to be making anything public,’’ Adams told The Guardian.
“We want to make sure the environment here is supportive of staff and create a climate where they can feel comfortable and open to come forward and be screened knowing that any results will be kept strictly confidential.’’
Adams said he realizes a solid argument can be made that the public should be informed if the source is found and that source is a staff member.
But he said the public should also realize the hospital is doing everything it can to prevent a further spread of the superbug.
“The staff are under enormous pressure. They feel like they are under a microscope.’’ (Byline: Wayne Thibodeau)

Some readers may know that it is outbreaks among newborns that have demonstrated that the designations “community-associated” and “hospital-acquired” are passing out of usefulness. There have been several MRSA outbreaks in newborns and their mothers in the US (in New York City, Houston, Chicago, Los Angeles and Houston again because Baylor College of Medicine has been particularly alert to this) that were clearly nosocomial, and yet when the microbiology was done, were found to be caused by community strains.

Why does this matter? Well, for the PEI hospital, it may not: They have an outbreak, it appears to be nosocomial in nature, and whether it is HA left over from their earlier outbreak, or CA that came in via a health care worker or a pregnant woman, mostly affects what drugs they give the children and mothers if those patients do in fact have infections. And for those of us who are primarily concerned with nosocomial infections, the distinction may also feel not-relevant: Failures of infection control are failures of infection control and should not happen period full stop.

But for those of us who are are also interested in the natural history of this perplexing bug, the answer to what is going on at the Queen Elizabeth will be an important piece of information, because it could underline that the distinction between HA and CA is becoming increasingly artificial. The epidemics are converging.