What the HAC?!

The University of Wisconsin (UW) Hospital is an excellent institution with a stellar infection prevention program. In fact, last year they won the prestigious U.S. Department of Health and Human Services (HHS) Partnership in Prevention Award, which recognizes “prevention leaders in the U.S…who have achieved wide-scale reduction and progress toward elimination of targeted health care associated infections.” Sadly, this achievement may not be enough to keep HHS from levying financial penalties against UW for high infection rates. 

Yes, the Hospital Acquired Condition (HAC) scores have come out, and have been generating a fair bit of media coverage, focused on those hospitals most likely to face financial penalties. Funny thing, though—the hospitals most likely to lose money under this program share a lot of characteristics:

“who is getting penalized? Large, urban, public, teaching hospitals in the Northeast with lots of poor patients. Who is not getting penalized? Small, rural, for-profit hospitals in the South. Here are the data from the multivariable model: The chances that a large, urban, public, major teaching hospital that has lots of poor patients (i.e. top quartile of DSH Index) will get the HAC penalty? 62%. The chances that a small, rural, for-profit, non-teaching hospital in the south with very few poor patients will get the penalty? 9%.”

Interesting. Explanations for these findings include: (1) small size, rural location, southern region and for-profit status magically translate to higher-quality, safer care, or (2) this HAC metric is bullshit, as it obviously doesn’t adequately control for myriad variables that are associated with the score but that are not indicators of quality and safety. What variables? Intensity and accuracy of surveillance, and variation in infection risk of the different patient populations, for starters.

I can overlook bullshit when it brings more attention (and resources) to the critical task of infection prevention. Unfortunately, this particular form of bullshit does the opposite (unfairly punishing already cash-strapped hospitals with financial penalties). As others have pointed out, the current HAC metric is well-intentioned but obviously flawed, and in desperate need of fixing.  

Reality bites: human bites and infection prevention

Our posting has been slow, and will continue to be for a short time due to clinical service and travel schedules. However, I thought now was a good time to review the management of human bite wounds. There are summaries in Medscape and UpToDate, a literature review in this trauma journal, and even national (UK) guidance on management. There is not uniformity in the literature about the need for antibiotic prophylaxis, though most would use something like amoxicillin-clavulanate if the bite punctures the skin, particularly if it involves the hand or another joint capsule or tendon. Remember also to assess need for a tetanus booster, and to evaluate for bloodborne pathogen exposure. Rabies in humans remains rare in most parts of the world, and in the most recent case I’m sure there will be at least a 10-day observation period for the biter.

Bare below the elbows: Making progress

We have had a recommendation for bare below the elbows (BBE) in the inpatient setting for 5 years at my hospital. No mandate, just a recommendation. And it's been a fairly soft sell. My perception has been that over time a greater proportion of our healthcare workers have adopted (BBE), but we've never formally measured it. Since our hand hygiene observers roam throughout the hospital, we asked them to simultaneously record BBE status while they were collecting their hand hygiene compliance data. So here's a first look: 2 weeks of observations (n=1,560). Note that HCWs were not counted repeatedly and our definition of BBE was strict (i.e., a wrist watch or bracelet was defined as noncompliance). The graph below shows the overall compliance and the compliance stratified by job category:

Nurses and nursing students demonstrate high rates of compliance. On the other hand, physicians and medical students are least likely to comply. Nonetheless, nearly 40% compliance in physicians is higher than I would have predicted. Medical students have two problems: they just love the white coat and they are concerned about how they will be perceived by their evaluators if they don't wear it. Clearly, we have some work to do there. Overall, though, I'm pleased with these results: 2/3 of patient encounters are by HCWs who are BBE. One caveat is that these data were collected in June. I expect the data will look different in January. We'll keep watching....

Adventures in the microbiome (part 2)

There's an intriguing case report that was just published in Clinical Microbiology and Infection. The authors describe a 60 year old man status-post renal transplant who had 8 episodes of transplant pyelonephritis with ESBL-producing E. coli. Due to graft failure, transplant nephrectomy was performed. Despite that, he remained persistently rectally colonized with the infecting strain, and was therefore removed from the waiting list for re-transplant. He then underwent fecal transplant via a nasoduodenal tube. One week later, rectal culture was still positive for the ESBL E.coli. However, beginning 2 weeks post-transplant, his rectal culture was negative and remained negative during 12 weeks of follow-up. Due to the fecal transplant, he is now back on the transplant waiting list.

Over a year ago, I blogged about a study where fecal transplantation was used to successfully eradicate VRE colonization in mice, so biologic plausibility clearly exists for MDRO decolonization. This indication could potentially greatly increase the demand for a procedure that is limited on the supply side (i.e., too few providers willing to perform the procedure). But it's another great example of the importance of the microbiome and the implications of being able to therapeutically alter it.

Photo: OpenBiome

Adventures in the microbiome (part 1)

There's a really interesting new paper in Clinical Infectious Diseases on a novel treatment for recurrent C. difficile infection. In this retrospective, uncontrolled experience, 25 patients with recurrent C. difficile infection (mean number of relapses = 4, median days of illness = 135) were treated with either metronidazole or oral vancomycin, along with kefir (5 oz three times daily). The antibiotics were given for 2 weeks at a standard dose (i.e., vancomycin 125 mg every 6 hours). In the next 2 week period, it was given at 3 times standard dose once every 72 hours (i.e., 375 mg), followed by 2 weeks of 2 times standard dose every 72 hours, then 2 weeks of standard dose every 72 hours. This strategy is known as staggered and tapered antibiotic withdrawal (STAW). The kefir was continued for 2 months after the antibiotic was discontinued.

I had to learn about kefir as I knew very little about it. It's essentially milk in which the lactose has been fermented by bacteria. It contains 10 strains of bacteria at a concentration of 7-10 billion CFU/cup. Thus, it's a big gun probiotic, and comes in several different flavors and forms (liquid, frozen, yogurt, cheese). You can find it in most grocery stores.

The end result was that 84% of the patients treated with STAW + kefir were diarrhea-free at 9 months. Again, this was an uncontrolled study, but nonetheless quite intriguing. I will certainly try this regimen in patients with recurrent C. difficile as an option for patients who either don't want to have a fecal transplant or would like to try this before resorting to transplant. I also wonder whether we should be serving kefir to hospitalized, nonimmunosuppressed patients as a prophylactic strategy for C. difficile. This weekend, I'll sample some of the products myself.

Tomorrow, I'll tell you about another interesting manipulation of the gut microbiome.

Say what?! Colonized patients (but not infected patients) contaminate the hospital environment

There is a continuous debate in infection control about whether to actively screen patients for MDRO colonization and subsequent isolation. Alternatives to active screening include passive surveillance, where only patients found to be infected through clinical cultures are isolated. Frequently, passive surveillance is justified by saying that infected patients will have a higher bio-burden compared to colonized patients, so they would be more likely to contaminate healthcare workers hands and the environment. However, is this in fact true? Are infected patients more likely to contaminate their rooms than colonized patients?

In part to answer this question, Lauren Knelson and colleagues from Duke and UNC just published a study in the July ICHE that measured the contamination of rooms after patients colonized or infected with MRSA or VRE were discharged. 48 rooms (33 from colonized patients, 15 from infected patients) were sampled using Rodac plates after patient discharge but before terminal room cleaning. Numerous sites were sampled including: sinks, toilet seats, bedside tables, bed rails, chairs, floors, TV remotes, carts, and laundry bins. This is a very small study, but even with the limited sample size they found that median CFU were higher in colonized vs infected patients' rooms (25 CFU vs 0 CFU, p=0.033). As you can see in the figure, the distribution of room contamination was greatly skewed towards higher levels of contamination at discharge from colonized patient rooms.

Some caveats: (1) More surfaces were sampled from colonized patient rooms than infected patient rooms (6.52 ± 2.47 surfaces vs 4.07 ± 2.12 surfaces; P = .02), so it's possible that surface selection could have biased these findings; and (2) Colonized patients stayed twice as long prior to discharge as infected patients (median 16 vs 7 days, p=0.28). Even though p > 0.05, this could be important since occupied rooms aren't "terminally cleaned" and "time in room" must increase contamination.

If these findings are validated, they have important implications. First, isolating infected patients (passive surveillance) would be expected to have less utility than expected. Second, the significant contamination of colonized patient rooms prior to terminal cleaning should be a reminder that we need to identify and implement environmental cleaning technologies that work continuously during the patient stay and not just focus on terminal cleaning. Finally, since infected patients would have received effective therapeutic antibiotics, these findings support the idea that effective antibiotics are important adjuvants for infection control. If true, this suggests that as the MDRO crisis expands in the absence of novel antibiotic discovery, infection control will become far more difficult (see 2011-2012 NIH KPC outbreak).

Stewardship Effective in C. difficile Prevention: A Meta-Analysis

As Dan mentioned last week, when 15% of asymptomatic hospitalized adults carry toxigenic strains of Clostridium difficile, it should alert us to focus on antimicrobial stewardship as a way to prevent CDI. But how effective are stewardship programs and does it matter what type of program you implement in your hospital? If only there was some sort of systematic review or meta-analysis to guide or decision making.

As if on queue, Leah Feazel and Marin Schweizer at University of Iowa published such a review and meta-analysis titled "Effect of antibiotic stewardship programmes on Clostridium difficile incidence" in JAC earlier this spring. Typical of projects completed by Marin and her group, they thoroughly combed the literature for papers. Here they identified 891 articles, reviewed 78 full articles and included 16 studies in their final analysis. Over all, stewardship programs were associated with a 52% reduction in CDI incidence. Importantly, programs appeared effective when implemented in whole hospital or geriatric settings and when utilizing a persuasive approach or a restrictive approach. I've provided the forest plot of studies below. An additional note is that the studies utilized various quasi-experimental study designs and based on the funnel plot, there appeared to be little publication bias.

Key points: (1) Stewardship works for CDI prevention, but it would have been nice if there was at least one funded RCT or cluster-RCT. (2) The meta-analytic approach, that Marin has pushed through her reviews of SSI bundles and hand hygiene interventions, is a fantastic way to guide medical decision making and should be considered for inclusion in future HAI guidelines. The reality is that infection prevention studies overwhelmingly utilize quasi-experimental designs. Why not identify the highest-quality QE studies and rigorously meta-analyze them as done here?

Laundering White Coats - We are asking the wrong question!

There is a very nice survey of bare-below-the-elbows perceptions and practice in this month's ICHE by co-blogger Mike's group. They asked 300 attendees (190 or 63% responded) at medical and surgical grand rounds about their beliefs and behavior concerning wearing white coats, neckties and wristwatches. I've posted the results below. As expected (since Mike has recommended BBE at his hospital since 2009), most thought that white coats were vectors and that not wearing a white coat would not alter patients' perceptions of them. Most did not wear white coats daily, neckties (males only) or wristwatches. Approximately half practiced the bare-below-the-elbows approach.

This all seems great except that it occurred to me that this group, and me and everyone else have asked the wrong questions as far as laundering practices of white coats. We've generally asked if the clinicians washed their coats daily, weekly, monthly, etc., when we should be asking them if they washed their white coats between patients! Asking about daily or monthly! laundering would be like asking about daily or monthly hand hygiene! Of course, this is ridiculous! I bet we could get hand hygiene compliance to 99% if the denominator was days instead of moments. By including a white coat laundering question with a lower bound of daily somehow implies that daily laundering is acceptable. Which it really isn't. Given that 96% of folks in this survey didn't wash their coats daily or every other day, this point is largely moot. Practically, we gotta give white coats the boot!

SHEA 2015 - New Format - Abstracts - May 14-17

I’m excited to announce that I will be co-chairing the 2015 SHEA meeting with Susan Huang. The new format will combine the highly regarded SHEA Basic Training Course in Healthcare Epidemiology with plenary, abstracts and symposia focused on infection prevention topics including long-term care, implementation science, science communication, MDROs, device infections and antibiotic stewardship. A strong emphasis will be placed on networking and mentoring sessions. The meeting will take place in Orlando, Florida (May 14-17th). The abstract site will be open from August 1, 2014 to January 16, 2015 and awards will be given to the top abstracts and posters at all career levels. So, get busy making science and look forward to seeing you in Orlando!

The enemy within

There are a couple studies out this month, one in CID (from WashU) and one in ICHE (from Houston), that carry the same message: a substantial portion (13-15%) of asymptomatic hospitalized adults carry toxigenic strains of Clostridium difficile in their GI tracts. Coming on the heels of this NEJM study using whole-genome sequencing to describe the genetic diversity of C. difficile strains, these studies advance an evolving narrative—that many cases of C. difficile-associated disease (CDAD) are not attributable to in-hospital transmission from other symptomatic patients (and thus are impervious to transmission-prevention approaches such as hand hygiene, contact precautions, and enhanced environmental disinfection). The major take-away point for me: it's all about the stewardship! Knowing that 15% of patients harbor toxigenic C. difficile should only increase the urgency of antimicrobial stewardship efforts.

The other major implication of these studies relates to the predictive value of highly sensitive PCR tests that target the toxin gene(s). To quote from the authors conclusion in Koo, et al:

“In the healthcare setting, where the majority of diarrhea cases are not attributable to CDAD and the prevalence of asymptomatic C. difficile colonization is greater than the frequency of CDAD, NAAT detection of asymptomatic colonization among healthcare-associated diarrhea patients may be contributing to a significant number of CDAD false positives.”

The UK have already changed their surveillance recommendations to require a toxin ELISA as confirmation of every positive PCR test. With lab-identified C. difficile now publicly reportable, I suspect more US centers will switch to two-step algorithms and/or begin restricting access to PCR-based assays to reduce the false positivity problems.

Enhanced scanning EM of C. difficile from the CDC's Public Health Image Library