Everything old is new again, with WGS!

As we’ve pointed out, whole genome sequencing (WGS) is the hottest new tool to help us decipher the epidemiology of healthcare-associated pathogens. Last week’s NEJM included a study using WGS to investigate the molecular epidemiology of C. difficile disease (CDD) in Oxfordshire, UK. In a 3.6 year study that included 1223 CDD patient isolates, the investigators found that only 333 were genetically related to at least one previously obtained isolate. Of those 333, only 126 (38%) had nosocomial exposure to the earlier patient. And the finding receiving the most attention: 45% of strains isolated were genetically distinct from all previous isolates.

The take home point? In current hospital settings (where we isolate every known CDD patient and use enhanced environmental measures to try to eradicate their C. difficile spores), symptomatic CDD cases are no longer the major reservoir for C. difficile acquisition. Focusing only on transmission prevention, then, will have a limited impact (antimicrobial stewardship, anyone?). Most obviously, further work is clearly needed to identify other sources of exposure and acquisition of C. difficile.

This may come as news to many, but probably not to Matt Samore, who made a similar observation….in 1994.

Why validation is important

A new study in the American Journal of Infection Control describes the validation of publicly reported central line associated bloodstream infection (CLABSI) data in Colorado. The study encompassed a review of data from ICUs at 35 acute care hospitals and 8 LTACHs for the first quarter of 2010. Charts of 519 patients with positive blood cultures were reviewed. Results of this study, as well as 3 other statewide CLABSI validation projects are summarized below.

	Sensitivity	Specificity
Connecticut	48%	99%
New York	74%	95%
Oregon	72%	99%
Colorado	83%	99%

These 4 studies show that 17-53% of CLABSI cases were misclassified as non-CLABSIs, primarily due to labeling CLABSIs as secondary bacteremias. Interestingly, the Colorado study attempted to delineate the underlying causes of misclassification. Two reasons were found to be significant: lack of an electronic medical record or data mining software, and review of potential cases by an infectious diseases physician (i.e., post-surveillance certification).

Given all the attention paid to publicly reported HAI data and the important implications with regards to reimbursement, it's imperative that hospitals produce valid data. However, validation projects remain infrequent due to their cost. We have a long way to go...

Dr. Donald Low on Dying with Dignity

Toronto ID physician Donald Low died last month secondary to a brainstem tumor. Here he discusses his thoughts on the diagnosis, telling his family and his fear of losing control. An amazing person to the end.

Source: Toronto Star

The Antimicrobial Hospital Room

Earlier this month I gave a talk at ICAAC where I shared my thoughts concerning the role that environmental coatings and antimicrobial textiles might play in limiting pathogen spread in hospital settings.  Several readers asked for copies of my talk, so I thought I'd just post a (moderately) modified version here.  In the same session, Mike gave an excellent talk describing the primary importance of hand hygiene, Andrew Stewardson discussed the counter point that hand hygiene wasn't the most important intervention and Andreas Widmer covered no touch disinfection methods (e.g. UV light hydrogen peroxide vapor). A great session - wish you were there!

NIH KPC Outbreak - The Final Word?

We've covered CRE extensively over the past couple of years.  Never so extensively as we did when the 2011 NIH KPC outbreak was first publicized last August following the whole-genome sequencing report in Science Translational Medicine. Almost a year has past since that report and kerfuffle, so it is nice to see that Tara Palmore and David Henderson have found the time to share their experiences controlling the outbreak and the media storm that followed the publication of the original manuscript. They decided to label the section on the public reaction the "Unintended Consequences of Publication." This title is very disturbing, as it highlights why many outbreaks like these are never reported - publication bias. I'm glad they weren't afraid to publish again, so that we can all learn for this difficult outbreak. The report is freely available in PDF over at CID. I'll stop writing and let you get on with your required reading.

In praise of the fist bump

A new paper in the Journal of Hospital Infection piqued my interest. It's a study about the fist bump. The investigators did an analysis of surface area and duration of contact comparing the handshake to the fist bump. They found that the surface area of the palm is about 4 times larger than that of the fist, and the handshake lasts 3 times longer than the fist bump. Like social distancing, cough etiquette, and bare below the elbows, the fist bump may be another simple behavior that could have the ability to reduce transmission of infection. It's worth exploring.

Photo: In These Times

"I am isolated here..."

The October issue of Infection Control and Hospital Epidemiology has an interesting paper on contact precautions by the University of Maryland group. This prospective cohort study of over 500 patients used standardized interviews to compare perceptions of inpatients who were cared for under contact precautions versus those who were not.

Patients who experienced contact precautions were twice as likely to report problems with their care. Specifically these patients noted poor care coordination and a lack of respect for their needs and preferences.

One particular quote from a patient stands out:

“I am isolated here. When people put on the gowns, I feel dirty and alone… [They] even had to wear them when I was being wheeled around for tests.”

So in a nutshell, another study tells us that contact precautions is a patient unfriendly intervention.

Photo:  Bob Tymcyszyn/QMI Agency in the Toronto Sun.

New CDC report on antibiotic resistance

Yesterday, the CDC released a new report on antibiotic resistant infections (full text here). It's a nicely done, mostly nontechnical report that seems primarily designed to raise awareness. There's not much new in the report except some updated estimates on the impact of these infections, which probably explains why the New York Times relegated its coverage to page 13. That piece, which quotes Eli, notes that the impact estimates are lowish, and CDC officials acknowledge that the estimates were intentionally conservative. As we've noted previously in this blog, we need more funding for prevention studies, new drugs, and better stewardship to protect the drugs we currently have.

MRSA rates continue to decline, but not in the community

About three years ago, Alex Kallen and colleagues published a study in JAMA describing the epidemiology of in invasive MRSA infections in the US from 2005 to 2008.  Dan and I wrote the accompanying editorial and said that "The most important finding of (Kallen's) study was documentation of a continuous decline of invasive MRSA disease, including an estimated 9.4% annual decrease in hospital onset and an estimated 5.7% annual decrease in health care–associated community-onset infections." At that time, community-associated infections were increasing.

Fast forward to 2013 and today's JAMA-Internal Medicine. Raymund Dantes and colleagues at the CDC have updated the results and now include data from 2005 to 2011. Using somewhat different methods, they report that there were around 80,000 invasive MRSA infections in 2011, which is 31% lower than 2005 estimates. Importantly, for the first time, the incidence of hospital-onset infections was LOWER than community-associated (no healthcare exposure) rates. Of all healthcare-associated infections, 77% were classified as healthcare associated community-onset or HACO. The continued declines in hospital onset and to a lesser extent HACO MRSA infections suggests that infection control methods including attention to hand hygiene and prevention bundles must be having a positive effect. Estimated deaths attributable to MRSA fell to 11,000.

However, minimal changes in true community-associated infections (a reported 5% decline) suggest that there is much more work to do preventing MRSA in the community. Unfortunately, we don't have evidence-based methods available to prevent community infections, so the lack of community declines is not surprising. I hope we begin to invest in HAI prevention research with a focus on non-acute care populations.

Other media mentions: NY Times, Live Science

Are "PSSA" coming back?

On the way to Lac St. Francois a couple weeks ago, we drove near St. Albans, Vermont, the location of the hospital outbreak mystery described in one of Mike’s recent posts (you may remember, the “case of the circumstantial evidence of a complicated conspiracy of hospital personnel using laboratory control strains to intentionally infect patients in order to ruin a doctor who claimed to have uncovered an illegal kickback scheme involving radiology services…”, yeah, that’s the one!).

In expert testimony from this case, the statement is made that penicillin-susceptible Staphylococcus aureus (PSSA) are extremely rare (“less than 2% of all S. aureus isolates”). This widely-held assumption (that PSSA are basically “extinct”) is incorrect, and in some centers there appears to have been a substantial increase in PSSA over the past few years. See this report from John Crane that 15% of all S. aureus from ICU patients in Buffalo, NY, are now PSSA, and this report from IDWeek 2012 that PSSA accounted for 20% of all MSSA (and 13% of all S. aureus) from positive blood cultures in the Kaiser Permanente system (regional reference laboratory in LA). We plan to examine this issue as well in the next round of our nationwide S. aureus resistance surveillance.

The perception that PSSA no longer exist persists in part because many labs don’t test or report the drug (to detect inducible beta-lactamases, labs have to perform a beta-lactamase test on any S. aureus that tests susceptible, before reporting it).

Why is this important? It is another indication of how complex is the epidemiology of S. aureus, demonstrating that emergence and virulence are not necessarily tied to resistance, and that the “loss” of a drug may not be the end of the story—and also, of course, as a reminder that the drug of choice for PSSA is…..penicillin.

The Jumbo Squirting Bow Tie - Infection Prevention Dream Attire

There are so few effective interventions available to improve hand hygiene compliance. In addition, there are other infection policies, such as bare below the elbows, that are gaining acceptance as methods to prevent pathogen transmission. For example, Mike posted a few months ago about a JHI study that quantified the transmission of organisms from long vs short sleeved shirts and tie vs. no tie. The study reported that the lowest transmission from clinician to mannequin occurred when the attire was short sleeves and no tie. However, the significant flaw in this study was that ties were narrowly defined as neckties and excluded bow ties.

Enter a solution to all of our infection control problems: the Jumbo Squirting Bow Tie! This often overlooked clothing accessory is a veritable infection prevention dream. A bow tie can increase our professionalism and limit pathogen transmission. Add in the "Jumbo Squirting" action and you can squirt alcohol hand rub into the eyes of non-compliant clinicians (operant conditioning) and also into your own hands to improve compliance with the WHO 5 Moments. When you think about it, it doesn't get much better than that.

image source: halloweencostumes.com

Annual cost of HAIs in the US = $10 billion

A new paper in JAMA Internal Medicine aims to give us an update on the impact of healthcare associated infections in the US. Given all the focus on HAIs, particularly with the rollout of value based purchasing, this is an important study. The investigators performed a systematic review, which included papers that were published this year, to determine attributable cost estimates, used NHSN data for incidence estimates, then performed Monte Carlo simulation. Total cost of the 5 major infections (CLABSI, CAUTI, VAP, SSI and C. difficile) was estimated to be $9.8 billion per year. The table below shows the breakdown by infection type.

Eli may want to comment on the methodology of the study and the validity of the results, but I suspect these numbers will be cited frequently.

The hard work of infection prevention

It is Labor Day today in the U.S., which is meant to be “a yearly national tribute to the contributions workers have made to the strength, prosperity, and well-being of our country”. In that spirit, we recognize those who are on the front lines of infection prevention every day. Performing hand hygiene a hundred times per ICU shift, tracking checklists for device placement and care, carefully disinfecting the high touch surfaces in a patient room, meticulously reviewing medical records for HAI surveillance, analyzing scores of agar plates to find HAI pathogens among commensal flora—these activities don't sound particularly exciting, but all are part of the daily grind of infection prevention and require dedicated nurses, housekeepers, infection preventionists and laboratorians. As much as we need to advance the science in our field, new-and-improved HAI prevention approaches won’t make a difference without the continued hard work and attention to detail of these talented professionals. Happy Labor Day!