To CDC or not CDC - That is the Ebola Question

It's been a busy couple weeks out here in infection control land. We had our SHEA 2015 planning committee meeting in DC. There's an exciting program planned - can't wait to share it with you. While I've been planning Ebola symposia for the May meeting in Orlando, Dan and Mike have been very busy discussing and implementing Ebola management plans. If you haven't had a chance to read their excellent posts, you can peruse them all here.

The debate over the CDC droplet+contact precautions guidance is strangely similar (in an opposite day kinda way) to discussions around N95 masks during the 2009 H1N1 outbreak. To remind yourself of the debate, you can read one of Dan's 2009 posts on the topic. What is almost ironic is a quote included in the post: "when did influenza become Ebola." What is actually ironic is that back in 2009/2010, CDC recommended "respiratory protection that is at least as protective as a fit-tested disposable N95 respirator for healthcare personnel who are in close contact with patients with suspected or confirmed 2009 H1N1 influenza." Yet now, CDC does not recommend N95s in most clinical situations for Ebola. And if you're keeping score, in 2009 CDC wanted "higher-level" protection and hospital epidemiologists wanted "lower-level", while in 2014 most hospital epidemiologists are implementing policies that extend way beyond CDCs recommendations.

All of that is by way of background to a thoughtful commentary in Annals of Internal Medicine by Michael Klompas, Daniel Diekema, Neil Fishman and Deborah Yokoe. The authors carefully review the data behind the CDC's current guidance and suggest that hospitals stick closely to the current recommendations. They claim that exceeding the CDC guidance could paradoxically increase health care worker risk and anxiety while also increasing cost and waste. They also suggest that exceeding "CDC's recommendations fans a culture of mistrust and cynicism about our nation's public health agency." The only thing I would add is that no matter what's included in your local Ebola management plans, don't forget the ice cream.

image source: The Onion

Living and breathing = aerosol-generating procedure

Eli, who is busy this week attending ScienceOnline2013, pointed me to this newly published study in Journal of Infectious Diseases on influenza transmission. Werner Bischoff and colleagues at Wake Forest measured influenza virus RNA concentrations in air samples taken between 1-6 feet from influenza-infected patients’ heads during routine care. Among the 61 influenza patients they analyzed, 26 released measurable influenza RNA into room air, and 5 did so in very high concentrations. The figure below, from the paper, shows that small particle aerosols containing influenza RNA could be detected 6 feet from the patient’s head (for 9 patients, at levels exceeding their low estimate for a 50% human infectious dose).

What does this mean? Well, this report confirms that some of our influenza patients (those we’ve previously termed “superspreaders”) expel airborne virus in small particles (capable of long-distance spread) even when they aren’t undergoing an “aerosol-generating procedure”. Life with influenza, for them, is an aerosol-generating procedure.

How to translate this into reduced transmission in healthcare settings is tricky, and Caroline Breese Hall’s commentary is worth reading in this regard. A couple things to keep in mind—these investigators measured RNA, not viable virus. And even if we assume transmissibility from the RNA numbers, only a small number of the 61 influenza patients were high-concentration small-particle aerosol emitters. These data alone don't support making sweeping changes in practice for all patients with influenza-like illness (e.g. N95 masks, negative pressure rooms). The challenge is to learn how to identify potential “high risk emitters” early, or to identify specific settings when practice change is needed (based upon dynamics of the community outbreak, etc.).

Anti-MRSA N95 mask?

I don't get this.  FDA has just approved an antibacterial N95 mask. The SpectraShield mask is labeled as an N95 surgical respirator with activity against S. pyogenes, MRSA, and H. influenzae when the bacteria are exposed to the outer surface of the mask.  When should these be used and why?  Is there evidence that in settings where an N95 should be used (i.e. caring for TB+ patients) that healthcare workers are contracting MRSA or Group A Strep? Are surgeons acquiring MRSA in the OR from their patients?  I probably missed the publications where they compared HCW acquisition rates between standard N95 and antibacterial N95. Please forward them along. 


PR Newswire, April 8, 2011

Hurry up, CDC

It has been a while since we blogged about the ridiculously stupid mask fiasco, mainly because the 2009 H1N1 virus is off the radar in most parts of the country and world.

This hasn’t stopped California OSHA from citing UCSF for not requiring N95 masks for the care of patients with suspected or confirmed 2009 H1N1. A post from the EIN this morning details the citation, which includes a fine and a requirement to rectify the situation by June 6, 2010. Here is a short excerpt from that EIN post:

I am…concerned about the short time window which we have been given to rectify the situation. Given the availability of 2009 H1N1 vaccine and increasing evidence in the literature that N95 masks are not superior to surgical masks, we plan to appeal before making a change in our practice; however, it is unlikely that OSHA will be willing to consider such an appeal without a formal change in the CDC guidance. I have heard that the CDC will soon be providing updated guidance on infection control practices for 2009 H1N1 - does anyone know the status of these guidelines and when they will be available?

Given that the “2009 H1N1” is going to be with us as a seasonal strain now, the CDC has only two options that make any logical sense: either back off the mistaken N95 recommendation, or begin requiring N95 use for all suspected or confirmed seasonal flu.

It would be nice if CDC acted quickly, and if OSHA held its fire until new guidance is issued.

Addendum: Rather than spending its time and resources doing post-hoc punishment of hospitals that responded appropriately to 2009 H1N1, California OSHA should be doing more to reduce the real threat of HIV transmission in the porn industry. So far, Cal OSHA has taken the bold step of “setting up an advisory committee to study the issue”.

Who is that masked...college student?

Researchers Allison Aiello and colleagues at the University of Michigan just published a study in the February issue of JID that assessed the benefit of (a) face masks or (b) face masks + hand hygiene vs. (c) control in preventing ILI in college residence halls (dorms) during the 2006-7 flu season. Each group (cluster) consisted of either one very large hall or a combination of 3 smaller halls (2 groups) for a total of 7 randomized halls. 1297 students were included in the study. Interestingly, spring break occurred during the study period which may have impacted the results. To bad the analysis couldn't tell us whether heading to the beach or skiing reduced the risk of influenza. In any case, they reported significant reductions in ILI in the mask+hand hygiene group during weeks 4-6 and in the mask only group during weeks 4-5 after influenza was first detected on campus.

An accompanying editorial by Titus Daniels and Tom Talbot, both at Vanderbilt, places the new findings in the context of the recent H1N1 'pandemic' and the N95 respirator debate. Importantly they suggest that the benefits seen in both face mask arms of the study may have been secondary to reduced viral shedding from infected mask wearers. They are correct to point out that the Michigan study supports the benefits of hand hygiene and it was also great to see them re-emphasize the importance of annual vaccination, particularly in health care workers, staying home when sick and compliance with proper respiratory etiquette.

Note: Both the article and editorial full-texts are available for free on the JID website; which is very nice for all who don't have a personal or university-based subscription.

I'll beat a dead horse...

See here for CNN's coverage of the swine flu mask debacle, which is well written and a primer for anyone who hasn't been following the debate.

"Not a retraction"....the pushback

Not surprisingly, the lead author of the now-infamous mask study is defending her findings and claiming her data still demonstrate superiority of N95s over surgical masks for protection against influenza. She also claims (as does another IOM member) that this study didn't influence the IOM report.

Really? Dr. McIntyre was a member of the IOM committee, and her recent comments make it quite clear that she long ago decided which mask should be used during influenza epidemics.....to claim that the work her group presented to IOM did not influence the final report is laughable. Us infection control types might not be sharp enough to detect critical flaws in a cluster randomized trial analysis......but we're not stupid.

Mask study FAIL

This is the audio of the IDSA presentation I referred to here.

I'm pretty sure someone has presented data from the same study at ICAAC and IDSA before....but I'm not sure if anyone has ever done so and also changed their conclusion 180 degrees....and in the process influenced a major IOM report that led to a misguided national recommendation for infection prevention that resulted in nationwide shortages of personal protective equipment.

How can a single study do so much damage before undergoing peer review? Yikes.

Never mind!

The same authors who claimed their study results were so convincing that it was no longer ethical to recommend surgical masks for the care of patients with influenza have now admitted that their analysis was flawed, and that their study (when analyzed correctly) shows no difference between N95s and surgical masks for protection of health care workers from influenza transmission (a conclusion now consistent with the JAMA study by Loeb, et. al.).

These data were cited as being of major import in the IOM report, which of course was a major determinant in the CDC decision to stick with N95s for all care of those with ILI during the H1N1 influenza pandemic.

I wasn't at the IDSA presentation where this retraction occurred, but I imagine it involved one of the authors going up to the microphone, meekly stating, "never mind", and rushing off to catch a flight back to Australia.

OSHA places health care workers at risk

Here is OSHA's statement on "H1N1 related inspections". By encouraging (i.e. requiring) hospitals to use their existing N95 supply for all contacts with probable H1N1 patients (as recommended in current CDC misguidance), they are increasing the likelihood that N95 masks will not be available when they are really needed to protect health care workers.

New H1N1 infection control guidance from CDC

The CDC will soon issue updated infection control guidance for nH1N1 in health care settings. Details of the impending conference call are here:

The Centers for Disease Control and Prevention (CDC) and the Department of Labor would like to invite you to join them on a conference call to update and inform stakeholders about the release of the revised 2009 H1N1 Influenza: CDC Guidance on Infection Control in Healthcare Facilities. This conference call will have speakers from the CDC, National Institute for Occupational Safety and Health (NIOSH) and Department of Labor/Occupational Safety & Health Administration (OSHA). Speakers will address various topics related to updated recommendations in this guidance. Call information is provided.

What: Conference Call/Information Sharing Session
Date and Time: Wednesday October 14, 2009 at 1:00 PM ET
Speakers: representative from CDC, NIOSH, and Department of Labor/OSHA
Call-In Number: 888-283-2960
Passcode: 7113863

Please note that there will be a question and answer session following speaker
presentations. The revised 2009 H1N1 Influenza: CDC Guidance on Infection Control in Healthcare Facilities will be available following the conference call on the CDC H1N1 Flu Website at http://www.cdc.gov/h1n1flu/guidance/.

Expect the new guidance to be mostly the same as the old guidance, but to allow some "wiggle room" for hospitals to use surgical masks instead of N95s in order to preserve N95 masks for aerosol-generating procedures, TB control, etc.

The only reason to care about this is if you are in a facility or state that is bound by CDC guidance. We already follow the Iowa Department of Public Health guidance, which mirrors that of the World Health Organization. Oh yeah, the other reason to care is if OSHA decides to enforce the CDC approach and to punish hospitals that have chosen reasonable and feasible alternatives. As described above, an OSHA representative will be on the call.

They write letters

SHEA sent a letter to Secretary Kathleen Sebelius today on the mask issue, in the wake of the JAMA study by Loeb, et al. I’ll link to the whole letter later if I can find it online, but I wanted to highlight this sentence:

“Rigid policy mandates that are not based in science but rather in fear will have an unintended, negative impact on our ability to deliver safe and effective care to our patients…...”

This applies to so much more than the question of which mask to wear to protect health care workers from influenza.

Mask vs. Mask

Well, the results of the Loeb study I previously referenced are now published in JAMA. This represents the ONLY randomized controlled trial comparing N95 masks to surgical masks for protection of HCWs against influenza that is published in the peer-reviewed literature. The accompanying editorial, by Arjun Srinivasan (CDC) and Trish Perl (Hopkins, and member of IOM committee), is here.

Who you callin' unethical?

Many of you have probably already seen the news articles about the Australian study on the effectiveness of surgical masks versus N95s for prevention of influenza. The lead author of this study was quoted as saying, “It would not be ethical to recommend surgical masks for health-care workers”.

That’s a bold statement, and wrong. Even if one posits the superiority of N95 masks over surgical masks for protection of health care workers against influenza, there is a very old ethics principle (attributed to Immanuel Kant) that “ought implies can.” And at this time, it is simply not feasible for all front line health care workers to don N95 masks for the entirety of their shifts (for many reasons, not the least of which is that there simply aren’t enough masks).

But this assumes that this single study is definitive. I understand it is to be published soon, but I am unaware at this point of the results of peer-review of this work.

In addition, there is another randomized trial that came to a different conclusion about the effectiveness of surgical masks versus N95s. The complete results of this study can found at this link (to see specific outcome differences one must scroll down and open those windows). I’ve pasted the abstract below, which was presented at the 26th International Congress on Chemotherapy and Infection in Toronto in June. Both studies will apparently be published in JAMA in the near future. Until then, I’d advise Dr. MacIntyre to tone down the rhetoric about what’s “ethical” as we all do our best to protect both patients and health care workers during this trying flu season.

Randomized Control Trial to Study the Efficacy of the Surgical Mask Versus the N95 Respirator to Prevent Influenza

Mark Loeb, MD, et al.

Context: Data about the effectiveness of the surgical mask compared to the N95 respirator for protecting healthcare workers against influenza are sparse. Given the likelihood that N95 respirators will be in short supply during a pandemic and not available in many countries, knowing the effectiveness of the surgical mask is of public health importance.
Objectives: To compare the surgical mask to the N95 respirator in protecting healthcare workers against influenza.
Design: Non-inferiority randomized controlled trial Setting: Emergency departments, medical, and paediatric units in eight Ontario tertiary care hospitals.
Participants: 446 nurses
Interventions: Assignment to either a fit-tested N95 respirator or a surgical mask when providing care to patients with febrile respiratory illness during the 2008-2009 influenza season.
Main outcome measures: The primary outcome was laboratory-confirmed influenza measured by PCR or a four-fold rise in haemaglutinin titres. Effectiveness of the surgical mask was assessed as non-inferiority of the surgical mask compared to N95 respirator.
Findings: Between September, 2008, and January, 2009, 478 nurses were assessed for eligibility and 446 nurses from eight centres in Ontario were enrolled and randomly assigned the intervention; 225 were allocated to surgical masks and 221 to N95 respirators. Influenza infection occurred in 50 (23.6%) of nurses in the surgical mask group and in 48 (22.9%) in the N95 respirator group (absolute risk difference 0.73%, 95% CI -8.8 to 7.3; p=0.86); the lower confidence limit being inside the non-inferiority limit of -9%.
Interpretation: The surgical mask was non-inferior to the N95 respirator for preventing influenza among healthcare workers.

ClinicalTrials.gov number NCT00756574.

The Ridiculously Annoying Mask Fiasco

I’m so tired of blogging about this; I’ll try to make this my last entry on this topic. But the brilliantly-timed IOM report has now placed incredible pressure on U.S. hospitals to procure enough N95 masks to allow use for all direct contact with patients who have febrile respiratory illness.

But there aren’t enough masks. Not even close, from what I understand. Our hospital was just informed that our large order is “behind 15 other very large orders”. Who knows when we’ll get them?

Tom Freiden referred to this issue in the CDC conference call when he stated that IOM’s charge was only to look at the science (which is inconclusive), not at feasibility. If CDC plans to issue new guidance that takes feasibility issues into account, I suggest that they do so very soon.

Meanwhile, we have reassuring data from the Southern Hemisphere, which is now near the end of its annual influenza season. Almost all the circulating virus this year was H1N1, and the season was….(drum roll)…..much like other recent influenza seasons. Pneumonia and influenza related death rates in Australia since 2005 are illustrated below:

Institute of Medicine to weigh in on PPE for influenza

We’ve blogged extensively about the discordance between CDC and WHO guidance on the use of personal protective equipment (PPE) while caring for H1N1 patients in healthcare settings. You can read our posts on this here, here, here and here.

Looks like IOM is now going to weigh in. You can find their project scope (or “charge”) here, along with links to the committee membership. The project specifies “novel H1N1”, but that seems very silly to me. No robust data exist to suggest that transmission of the novel H1N1 differs in any substantive way from that of seasonal influenza. So any conclusions or recommendations that come from this committee should be applicable to all influenza viruses, not just the “novel H1N1”.

The ad hoc committee has to report its findings to CDC by September 1st. So what do you think the likelihood is that we’ll be using N95s for care of all patients with seasonal influenza, every year?

Better guidance needed from CDC on respiratory protection

CDC continues to recommend contact precautions plus the use of N95 masks for the care of patients with suspected or confirmed H1N1 influenza. However, we have received noticed from a major manufacturer that the demand for N95 masks is outpacing the supply. Thus, we are not able to obtain any additional supply over our usual allotment and our inventory is falling. Better guidance from CDC is sorely needed. The WHO continues to recommend standard plus droplet precautions except when an aerosol generating procedure is performed, for which an N95 mask should be worn.