The landscape of MRSA in America's largest healthcare system: Acquisition carries a 1-4% chance of infection in the following year!

Note to readers: This is another guest post by esteemed FOTB (friend of the blog) Dr. Daniel Morgan. Soon I'll give him the keys, in the hopes he'll post more frequently!

One of the most informative articles I’ve read in 2018 on healthcare-epidemiology has largely sailed under the radar. This article summarizes the numbers for MRSA across the US Department of Veterans Affairs (VA). In the VA we perform active surveillance testing on admission and discharge to acute and long term care centers. A wealth of data is collected reflecting community and academic settings across all regions of the country. The reporting of extensive numbers without a single message probably made this study less eye-grabbing. The excellent team of data-savvy researchers at the Salt Lake City VA/University of Utah have done extensive cleaning and validating to come up with outcomes for almost 1 million first admissions from 2008-2015. Yes, 1 million patients who had MRSA surveillance tests on admission and discharge. They then followed them for a year post discharge to look for infection. Some may quibble that “acquisition” isn’t using whole genome sequencing but no past study comes close to having this much data. Congrats to Rich Nelson, Mike Rubin and colleagues! People should be dissecting these numbers for much guidance on MRSA. (And Mike, sorry to Lance Peterson you by reinterpreting your own data…but at least I didn’t title this “Mike Rubin’s team shows MRSA surveillance and isolation are of low value!”) 

A few nuts and bolts:

I will focus on non-ICU admissions for ease of numbers, but ICU conclusions are almost identical. There were 902,354 total patients admitted to non-intensive care units. 

• 7.3% (65,783 patients) were MRSA + on admission 
• Fewer than 1% (0.81%, 7,342 patients) acquired MRSA (negative on admission, positive on discharge)

They defined infection a few different ways: 

• Definite infection: MRSA + culture from sterile site—blood, CSF etc. 
• Likely infection: All Definite infections & patients on anti-MRSA antibiotics within 5 days culture 
• Possible infection: Any positive MRSA culture from any site (reflecting colonization and infection) 

Some conclusions: 

Acquisition of MRSA carries a small risk of developing infection. In contrast to past articles, across a broad population, this is true even within a year of admission. For non-ICU admissions, acquisition of MRSA carried a 1%-4% risk of definite or likely infections within a year. (7% risk of possible infection) (even if discharged from an ICU the numbers are only 2.5-8.6% develop infections or colonization) 

Previous studies have reported an absolute risk > 30%! Studies were often in a single tertiary care center, displaying how little those hospitals reflect the general population. This means THE BENEFITS OF PREVENTING ACQUISITION OF MRSA ARE SMALL. (Infections, however are important) 

I know Eli and other friends may disagree, but we need to focus on infections. Preventing those is the metric that matters. >95% of patients wouldn’t even know they acquired MRSA (as they never would have had an infection). 

The vast majority of MRSA infections occur in people who were MRSA + at admission, not those who acquire MRSA. This paper estimates that fewer than 10% of definite or likely MRSA infections occur in those who acquire MRSA during the admission. Let’s focus our efforts to prevent most MRSA infections. Contact precautions don’t help people who are already colonized. They instead require infection prevention efforts like device insertion bundles, chlorhexidine, and avoiding antibiotics. 

The official conclusion of their paper--that acquiring MRSA poses greater risk than being colonized on admission--is true, but the effect is small: ~1% absolute difference. 

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Bad news for all haters of Staphylococcus aureus disease. Pfizer just announced their large Phase 2b clinical trial for a S. aureus vaccine to prevent post-operative infections with S. aureus among spinal surgery patients was futile to continue. 

press release

Exactly what this means for the Pfizer staph vaccine program is unclear. according to the press release, there was no indication of any safety concerns, but rather a low likelihood of the study to reach statistical significance of any of their primary clinical endpoints: 

• S aureus BSI and/or deep incisional or organ/space SSI occurring within 90 days of elective open posterior spinal fusion procedures with multilevel instrumentation. 

STRIVE was evaluating a Staphylococcus aureus 4-Antigen (SA4Ag) Vaccine. I have to admit I did provide some consultation to Pfizer's advisory group on this study, including a modest one time consulting fee (full disclosure!); however I have no insider information on the trial itself. As an advocate for making the public health case for a S. aureus vaccine, I (again) find this development extremely disappointing.  

We hear reports that MRSA incidence is improving, mostly from NHSN type reporting - but to be honest I can't really find contemporary data to tell a clear story about S. aureus incidence in past few years. I know we are all making good progress with HAI prevention, hospital-onset MRSA, probably even S. aureus HAIs in general - is there room for clinical trial work in this arena?! or is S. aureus just a problematic pathogen to develop a vaccine!  Well a big thank you to Pfizer and NIH and the other Pharma companies rising and investing to develop an efficient S. aureus vaccine - I am sorry STRIVE has ended, I hope the healthcare epidemiology community can continue to produce data to help make a rational argument for companies to invest in such development!.  

happy new year!

Scott. 

At the end of 2018, we remember and respect Influenza, 100 years after the great pandemic

The Mother of All Pandemics
In the 1918-1919 calendar year, the world experienced the worst influenza pandemic in modern times. Coming on the heels of WWI, the H1N1 pandemic occurred in three waves – in the spring of 1918, fall 1918 and spring 1919. Estimates suggest that the pandemic infected a third of the world’s population, with 50 million people dying worldwide, including 675,000 Americans. Mortality was high at extremes of ages, but what sets this particular pandemic apart was the significant mortality (over half of all deaths) in young, healthy 20-40yr olds. Why such devastating morbidity and mortality? Perhaps a combination of war-ravaged, crowded conditions, malnourishment, inadequate healthcare resources (many doctors/nurses were deployed at war), and poor hygiene. In the early 20th century, there were no influenza vaccines to prevent flu or lessen its symptoms; no antivirals to help reduce transmission; no antibiotics to treat post-influenza bacterial pneumonia. The Smithsonian National Museum estimated that the total death toll of the 1918 pandemic outnumbered military deaths in both World War I and II. You can watch a video created by the CDC about the 1918 pandemic here. This avian-origin H1N1 pandemic has been called “The Mother of All Pandemics”, setting the stage for all of the subsequent epidemic and pandemic strains of influenza we have experienced.

After 1918: Influenza still deadly, though not as devastating
In 1957-1958 an H2N2 avian influenza virus caused a pandemic resulting in 1.1 million deaths worldwide including 116,000 Americans. 10 years later, another avian-based virus H3N2 triggered a similar sized pandemic with 1 million deaths worldwide and 100,000 Americans. The H3N2 still circulates as a seasonal flu virus and is included in seasonal vaccines. The next major pandemic was triggered by a novel influenza A virus called H1N1pdm09 in 2009, originating in the United States. By this time, seasonal influenza vaccines had included H1N1 but this variant was completely different from the seasonal flu vaccine, resulting in an estimated over half million deaths worldwide and up to 18,000 Americans.

Today: There is still work to be done
Since 2009's pandemic, seasonal influenza is still prevalent, with an estimate of over 291,000-645,000 deaths from seasonal influenza worldwide. The highest mortality rates are in poorer, developing countries, with individuals at extremes of age being most vulnerable to death from seasonal influenza. We still do not have a universal influenza vaccine, though research is moving in that direction. The 2017-2018 influenza season brought a serious influenza epidemic, with 48.8 million illnesses, 959,000 hospitalizations and 79,400 deaths estimated in the United States alone. This week, the Infectious Diseases Society of America (IDSA) released updated guidelines for diagnosis, and management of seasonal influenza. In the guidelines, they recommend testing for influenza in upper respiratory specimens of high risk patients, when testing can reduce unnecessary additional testing/inappropriate antibiotics, or when testing can influence chemoprophylaxis for high-risk household contacts. Annual seasonal flu vaccination reduces the risk of influenza by 40-60% and is still recommended as the best way to mitigate the impact of seasonal influenza, but antiviral prophylaxis may be necessary in outbreaks or for certain at-risk populations. Other ways to prevent spread include hand hygiene, limiting contact with people who have influenza-like illness, and if you have such an illness yourself, STAY HOME. 

More than 166.6Million influenza vaccines have been distributed in the US as of December 20, 2018.The influenza vaccine may not always be a 100% match to all circulating strains, as we saw with last year's flu season.  This year’s vaccine contains an influenza A H1N1pdm09-like strain, an influenza A H3N2-like strain, and influenza B strains from the Victoria and Yamagata lineages. Updated this year, the Advisory Committee on Immunization Practices (ACIP) also recommends the live-attenuated influenza vaccine (FluMist); however, the American Academy of Pediatrics suggests this only be used if the alternative would be no flu shot at all. The CDC can explain the types of vaccines available and who should get them. 

Final thoughts about the flu 

Regardless of which vaccine is more appropriate, our ancestors would probably encourage us to just get ANY vaccine if it would help avoid recreating the influenza pandemic of 1918. There's still time - it's not too late so if you haven't gotten your flu shot, consider getting it today!

Final thoughts

This is my last post on Controversies. I’ve been writing online since 2000, first with residency and fellowship friends on qfever.com and then on various medical sites to pay off school debt and buy some non-futon furniture. In 2009, Dan and Mike were kind enough to invite me to join this blog and I’ve greatly enjoyed the camaraderie and experience. I could write a book about what I’ve learned and unlearned and the tremendous colleagues and science journalists that I’ve met.

Back in 2009, Mike, Dan and I were all at different institutions. For me, this blog was a place to try out ideas. I didn’t have any expectation to be perfect – only our families were reading. In fact, the blog name Dan/Mike selected was great – they acknowledged the imperfection of infection control science and that we needed a place to work through ideas, to be wrong - to fail. And I greatly appreciated the feedback on my posts. Failure is how we learn.

But in 2018, we three are all at Iowa and even though we’ve added tremendous new talent to the blog, we are still seen as an Iowa blog. Now, when I write deeply questioning posts about hand hygiene, I’m seen as writing with an institution behind me and I have to be more careful or safer. And it’s not just Iowa. As SHEA treasurer, I had to worry about how my posts would be viewed. I direct a VA HSR&D Center of Innovation and sometimes I worried about how my posts would reflect on the 70 people in our Center. I now have positions with ICPIC, the Decennial, and as ID Editor for JAMA Network Open. Too many filters, too much noise. 

Finally, it needs to be acknowledged that our readers and our field are amazingly generous. You have been incredibly forgiving when I’ve tried and failed. I'm incredibly grateful for your generosity.

I will miss this blog and our readers. Thank you. The title of my first post in 2009 was “The end of the beginning.” I think that’s right.

Eye Protection and Seasonal Influenza

At the last HICPAC meeting, Drs. Bryan Christensen and Ryan Fagan led an excellent discussion of the following question: should eye protection be included in droplet precautions for seasonal influenza and other respiratory viruses? 

Eye protection is one aspect of Standard Precautions, of course, to be used whenever there is a risk for splashes or sprays of blood and body fluids (BBF), or during aerosol-generating procedures. However, there is no recommendation for routine use of eye protection as part of Droplet Precautions—it’s an “unresolved issue”. 

Nonetheless, whenever CDC has had to issue interim guidance for new respiratory viral threats (SARS, MERS, novel influenza A viruses, etc.), they’ve included the routine use of eye protection. But seasonal influenza kills far more people annually than any of the novel threats, and there’s little reason to believe that seasonal flu strains can’t use the eye as a portal of entry (in addition to rarely causing direct ocular disease). The same applies to various of the other respiratory viruses (adeno, RSV, rhinovirus, hMPV, etc.). 

As is so often the case, we don’t have much published data to help answer this question: some work done in the 80’s suggested that eye protection was important for RSV transmission prevention, and Dr. Werner Bischoff demonstrated in an experimental system (air chamber into which live attenuated influenza vaccine virus was aerosolized) that the eyes could serve a portal of entry for influenza. So definitely wear goggles if Werner invites you to enter an airtight test chamber.

Anyway, thanks to Bryan and Ryan for their review (I will link to it when the transcript is out), and to HICPAC members for the lively discussion that followed…so what do you think? Does your center use eye protection routinely for droplet precautions for seasonal flu?

Progress on HAI progress: CDC portals and data

I spent about 2 hours with the new CDC HAI Progress Report – loosen your belt, it’s a big meal!  We probably had mixed perceptions about the recent alert to the 2016 HA progress report. Loads of information and analysis condensed down to a handful of bullets, all pointing to improvements in patient safety! The (very pleasant) surprise to me was that the format and delivery of the report has advanced to digital!! CDC has added the HAI progress report to the existing (and now updated) HAI AR Patient Safety Atlas Portal If you stop reading now – at least click on that link and explore and I will call this blog a success!

This report is several steps forward.  First, it pushes all of us to go to a place where we, being inquisitive minds, can wander and perhaps connect some dots within and between datasets. With the digitalization and visualization provided in the portal, the novice and experienced can more easily access and utilize these data. One can click through four distinct datasets, which now include state-summary statistics HAI infection rates/SIRs, inpatient stewardship activities, outpatient antibiotic prescribing rates, and inpatient antibiotic resistance metrics.

Now – the email alert. This year, well 2016 data, is the first to use the 2015 “re-baseline” efforts.

Unstated, but implied – the re-baseline effort includes the use of MBI (mucosal barrier injury) LCBSI as an event excluded from reported CLABSI rates, exclusion of yeasts (or low colony counts) from CAUTI rates, exclusion of “infection present on admission” for SSI (along with better patient-level risk adjustment), first use of risk adjusted metrics for VAE, and maybe slightly better models using more contemporary data for MRSA and CDI. 

With that said, 2016 performance suggests nationally patients are safer overall compared to the experience of 2015. Other than VAE which decreased by only 2%, everything else declined about 7-10% (I am rounding) compared to 2015. I understand many of the problems with risk adjustment and reporting bias that make these surveillance events poor performance measures for individual hospitals – but on the national level – I think these data do suggest fewer infections (o.k., perhaps some  widespread under-reporting—mixed reports on validation efforts in place).

Next – the overview of the current HAI Progress Report.   Although at first glance it seems the same as the info posted in the emails – CDC is offering more ways to track progress nationally – the number of states showing improvements (or worsening) compared to 2015, as well as the number states currently performing at levels better (or worse) then their 2016 contemporaries: 12 state perform better on at least 3 infection types compared to other states at the same time (2016). Now positive deviance nerds need to learn from these states to help the other states (or perhaps identify accuracy and validation issues at these states). The contemporary juxtaposition of SIRs is new, perhaps confusing (especially with CDC’s arcane explanation on how to interpret this: “SIRs statistically significantly lower than the 2016 national SIR are considered better than the 2016 national SIR”; curious if it ends up being useful to state programs. This year also is the first with more detail on inpatient rehabilitation facilities and long-term acute care facilities. Fewer data mean fewer statistical significant results, but these data are ripe for academic partners to latch onto as they try to partner with ARHQ, CDC, and state-programs to branch out into stewardship and prevention efforts in these types of facilities.

Finally, the portal – access it here.  Use the table view. No graphics to export for HAIs, only for other datasets. My pet peeve is that CDC still refused to list the no. of SSIs reported next to the number of surgical procedures reported to allow a crude attack rate. We still need to go to the technical tables for these values and calculate ourselves (see below). CDC, please stop making us jump through this hoop to be able to use attack rates for other purposes like planning studies, clinical trials, vaccine research! To all researchers and data nerds - the detailed technical tables should be downloaded examined (here), perhaps parsed out to our students and trainees, and used for different purposes that simply a “reporting requirement”.  I know there are many limitations to the accuracy of any one facilities reports and likely aggregate data up to the state or national level. However, as a long time national surveillance nerd all too familiar with the warts and ugliness of surveillance data, they do inform us, approximate the truth, and can help us ask the right questions and target the right populations. The more eyes using these data the more transparent the process will become, more uses of the data will be identified, patient safety should improve, and CDC will become more accountable to update (c’mon, where’s 2015 and 2016 NHSN AR data?! update the portal please!!),  maintain, and advance the public accessibility of useful data in our field.

Identifying Barriers to Hand Hygiene Audit and Feedback

This is a guest post by Daniel Livorsi MD and Heather Schacht Reisinger PhD from the University of Iowa Carver College of Medicine and the Iowa City VA Health Care System

Our research group recently published a qualitative investigation of hand hygiene in JAMA Network Open. The study describes real-life barriers encountered by 8 VA hospitals in their use of audit-and-feedback to improve hand hygiene compliance. For anyone involved in hand hygiene monitoring and improvement, the barriers we describe will probably not come as a surprise. In brief, we found that auditing hand hygiene compliance by direct observation was perceived to collect inaccurate data and created tension with frontline staff; the feedback process did not encourage positive change.

Although the importance of hand hygiene is widely acknowledged, our field’s understanding of how to improve hand hygiene compliance is still relatively primitive. All of the hospitals we visited had implemented audit-and-feedback, which was the focus of the study, but many were also using other strategies, such as environmental engineering and education. Despite these well-intentioned efforts, hand hygiene compliance rates at the participating sites were 49.8% (n = 9791) at room entry and 63.9% (n = 10 135) at room exit. It seems safe to assume that such poor compliance rates are common across all of healthcare. To meet regulatory standards (e.g. the Joint Commission), hospitals need to keep going through the motions of auditing, but wouldn’t it be great if all this effort could be directed towards interventions that actually work?

An accompanying editorial argues that all of these audit-and-feedback programs were missing one key component: immediate personalized feedback coupled to individualized action planning. In general, feedback is more effective if it is provided in real-time and is individualized, so this strategy is appealing. However, at the hospitals we describe, giving personalized feedback would likely face some logistical challenges, including limited personnel to perform these separate individualized audits and potential pushback from labor unions on the collection of individualized performance data. In addition, collecting individualized data still does not address larger questions about the accuracy of direct observations.

Like many processes in healthcare, improving hand hygiene will require both technical interventions and socio-adaptive changes. Clearly, compliance rates are not where they need to be, and the current strategies are not effective. I don’t pretend to know the answers, but as a field, let’s not give up on trying to find some solutions.

image credit: honoring University of Iowa Veterans