Monday, August 18, 2014

Emory's Ebola Unit

This NPR interview gives additional information about the unit.

Saturday, August 16, 2014

Ebola protection: How much is enough?

There's an excellent piece in today's New York Times that focuses on the key question hospital epidemiologists across the country are struggling with: what are the appropriate infection control measures to protect healthcare workers caring for patients infected with Ebola virus? We've blogged on this issue to some extent before (here and here). Are contact and droplet precautions enough (as recommended by CDC), or do we need Tychem suits, PAPRs, and fluid resistant booties, or maybe even something beyond that?

What do we know about Ebola viral disease to guide us in this decision?
  • The virus is transmitted via multiple routes: direct or indirect (fomite) contact with blood and body fluids (including urine, stool, vomitus, sweat, tears, semen, breast milk, and saliva), droplet, and fecal-oral. Airborne transmission is also possible if aerosolization occurs.
  • Healthcare workers are a major risk group for infection.
  • The disease manifestations drive transmission (bleeding, vomiting, diarrhea), leading to environmental contamination and contamination of HCW clothing, unprotected skin and mucosal surfaces. Simulated vomiting studies have shown that droplets can travel over 10 feet. The virus can remain infectious 1-2 days outside the human body.
  • Healthcare workers have become infected despite use of maximal barrier precautions.
  • If transmission occurs, the disease has a high mortality. 
  • There is no known effective antiviral therapy. Experience is too limited to understand the impact that state-of-the-art supportive care can have on improving mortality.
  • We have no post-exposure prophylaxis.

Now put yourself in the shoes of a 26-year-old ICU nurse with a 1-year-old child at home who has just been assigned to care for an Ebola-infected patient with active vomiting and diarrhea for a 12-hour shift. What level of protection would you want? It's nurses who will likely face the highest risk since they care for patients for long periods of time and have the most contact with blood and body fluids.

It's interesting in the New York Times piece to contrast the perspective of Nancy Foster, a non-HCW executive of the American Hospital Association, who works in an office far removed from the patient care setting, to that of Dr. Michael Callahan, an infectious disease specialist who has direct experience in Africa with Ebola outbreaks. Ms. Foster tells us that gloves, gown, face mask and eye protection are “perfectly fine.” Dr. Callahan notes that the "perfectly fine" strategy “led to the infection of my nurses and physician co-workers who came in contact with body fluids.” The Ebola veteran notes, “I understand the desire to maintain absolute protection in U.S. hospitals.”

How we deal with perceptions of risk is fascinating. The risks we choose to accept and those we don't can't be explained rationally. But that's quintessentially human. As I see it, healthcare workers that accept the challenge of caring for Ebola patients are providing a great service and face a level of risk that is hard to define. These brave souls deserve to have input on the personal protective equipment they wear. And if they want Tychem suits, so be it. Our job is to then ensure that they can safely use them.

Photo: Boris Roessler/DPA.

Friday, August 15, 2014

Influenza "Gain of Function" Research - Worried? Read on

Marc Lipsitch (Harvard School of Public Health) and many others are highly concerned about influenza "gain of function" research.  Recently, Marc sent around an email that I've posted below as some of you might want to support this effort. Those who would like to learn more about this issue, I suggest you read his recent NYT op-ed, which he mentions below, and also listen to yesterday's NPR Morning Edition discussion on the subject.

Dear Colleagues: 

I want to reach as many colleagues as possible about a very important issue, the growing experimental program underway at institutions around the world to create novel strains of influenza that are transmissible in ferrets, the leading animal model for human flu infection.  These so-called "gain of function" experiments create potential pandemic pathogens from virulent precursors that are not readily transmissible; as such they are a uniquely risky approach to studying influenza. A group of scientists and other concerned experts is calling for a curtailment of such experiments until a serious, quantitative, disinterested risk assessment has been performed to ask whether these experiments offer unique benefits, unattainable by safer means, that justify their unique risks. We have called for an Asilomar-like meeting to start such a process, which would include all points of view under a neutral sponsorship.

These experiments create pathogens which have the potential to spread widely if accidental infection occurs and could, in the worst case, lead to an uncontrolled pandemic. Recent events in federal labs in the US show that even in the leading laboratories, human error leads to the risk of human exposure. This is not an unusual occurrence; in the period 2004-10 there were two loss or release events PER WEEK in biocontainment labs in the US involving Select Agents. While the probability of such incidents in any given lab in a year can be estimated from available data, experiments that deliberately enhance transmissibility of influenza viruses present orders of magnitude greater risk than anthrax or wild-type, poorly contagious avian flu strains, because of the risk of transmission.

I am writing you to invite you to join the Cambridge Working Group,, by supporting our statement that these experiments should be curtailed until there is a serious, quantitative, risk-benefit analysis of what benefits are uniquely obtainable by this exceptionally risky class of experiments, and whether these unique benefits justify the risks involved. Note that we are not calling for a halt to work on dangerous pathogens in general; our call focuses on the creation of novel, transmissible dangerous pathogens, one of many techniques available for studying such organisms but a uniquely dangerous one.

The website has a link for you to add your support to that of a growing number of scientists and others, as well as several pages of links to relevant articles, press coverage and the like. For those interested, I wrote a recent New York Times op-ed on the topic. Much more detailed and technical information is available on the website.

Thank you for considering this request.


Thursday, August 14, 2014

SHEA 2015: Abstract Site Open

The planning continues for an exciting SHEA Spring 2015 Conference, which will take place May 14-17 in Orlando. The meeting will have a broader format while retaining the highly successful SHEA-CDC Certificate Training Course in Infection Prevention & Healthcare Epidemiology. New additions include a SHEA Certificate Course in Infection Prevention for Long Term Care and focused scientific abstracts related to healthcare epidemiology, including poster and oral abstract awards. The SHEA 2015 abstract submission site just opened and the deadline for submissions is January 16th. So, get excited, tell your friends and start doing science - we can't wait to see what you're doing! And remember, you can't win an abstract award if you don't submit an abstract.

Wednesday, August 13, 2014

Unintended Benefits of Antibiotics: Why antimicrobial stewardship is difficult

We frequently highlight the unintended consequences of antibiotic use, such as C. difficile or adverse drug events, as reasons to discourage inappropriate antibiotic prescribing and advance antibiotic stewardship. Avoidance of unintended consequences is also a major factor in physician selection of antimicrobials. Anecdotally, physicians prefer to avoid clindamycin because it's linked to CDI. In an old study, Jessina McGregor and I found that physicians were approximately twice as likely to prescribe an antibiotic if its use was associated with three days of diarrhea instead of five.

Unfortunately (for stewardship, not patients), antibiotics also have significant unintended benefits, which may drive their overuse. In the current issue of JID, Elizabeth Gilliams et al. report (free full text) a secondary analysis of a malarial therapy RCT (chloroquine +/- azithromycin) in Malawian children. 160 children with mean age 33 months were treated in each arm. Children in the CQ+AZ arm were 33% less likely to develop a subsequent lower respiratory tract infection and 26% less likely to develop a gastrointestinal tract infection than patients treated with CQ monotherapy. Time to development of a lower-RTI was 0.88 years when AZ was added vs 0.46 years with CQ alone, p=0.04. Time to first GI infection was also delayed with AZ therapy, 0.58 years vs 0.38 years, p=0.02.

Specifically, these finding are important because the CQ and CQ+AZ arms were considered equivalent for malarial therapy; however, physicians may now add azithromycin for these secondary benefits in addition to its potential to delay the reemergence of CQ resistance in the region. The number needed to treat was only 7 for both RTI and GI outcomes. Thus, for every 7 children given short courses of azithomycin during malarial therapy there will be one fewer case of GI infection AND one few RTI.

Lori Holtz and Phillip Tarr in an accompanying editorial (free full text) describe the difficult decisions now facing public health authorities in the developing world with regard to balancing the benefits vs harms of antibiotics. For example, earlier trials found that mass azithromycin for trachoma reduced infectious and all-cause mortality in children while the addition of amoxillin or cefdinir to malnutrition treatments reduced mortality by 40%. The editorial includes discussion of potential mechanisms behind the beneficial outcomes attributed to azithromycin. Importantly, they call for future studies to determine the etiologic agents causing the poor outcomes which azithromycin inhibits so they can be targeted and mass antibiotic exposure prevented. I hope they get what they ask for. However, these are likely bacteria, so I don't hold out much hope for research funding.

Sunday, August 10, 2014

Why are we dialing it up to eleven?

Yesterday, Dan posted an excellent summary of what's happening in US hospitals as they scurry to plan for the public health issue du jour--Ebola. He astutely points out that there seems to be a disconnect between what we know about Ebola transmission and what we're doing (or planning to do) with regard to safely caring for patients infected or suspected to be infected. I thought it would be interesting to examine what's driving the disconnect. As I see it, a number of factors are at play here:

Mixed messages

Michael Ramirez,
As noted by Dan, at a press conference prior to the transport of two Americans with Ebola infection to Emory University Hospital, Dr. Bruce Ribner stated: "Emory University Hospital has been asked to accept two patients who are currently in Africa infected with Ebola virus infection. Our facility was chosen for this because we are one of only four institutions in the United States capable of handling patients of this nature." Not stated, but nonetheless presumed by the infection prevention community is that the agency doing the asking was CDC, given CDC's physical proximity and given that quite a number of CDC physician-epidemiologists hold faculty appointments at Emory's schools of medicine and public health. However, just a few days later, CDC's primary message was that any hospital in the US should be able to safely care for Ebola patients.

Photo: Cellou Binani/AFP/Getty Images
It's also difficult to reconcile the CDC recommendation for contact and droplet precautions--highly familiar to all healthcare workers--with the images of healthcare workers on the ground in the outbreak epicenters and in Atlanta dressed in Tyvek spacesuits. And who hasn't seen the video footage of the infected American doctor emerging from the ambulance in Atlanta also dressed in the same manner? However, it's important to keep in mind that the exposure risk for healthcare workers in the outbreak setting, caring for multiple very ill, infected patients with scarce resources, is far different than the controlled setting of the average American ICU.

Fear and managing risk

Our greatest fears often revolve around areas where we lack experience, and very few healthcare workers in the US have ever cared for a patient with viral hemorrhagic fever. Importantly, not only does Ebola Fever have a high mortality rate and no proven effective therapies, there is also no post-exposure prophylaxis. A simple lapse in infection control protocol cannot be undone with a pill or injection. One way we attempt to manage fear is to overprotect: if one barrier works, two must be better. In general, redundancies mitigate risk, but this isn't absolute. As Dan pointed out in his post yesterday, we may inadvertently increase risk by complicating infection control protocols with gear that healthcare workers may find distracting, uncomfortable, and lack training to use. The litigious nature of American society also impacts our decisions regarding infection prevention strategies. And many healthcare workers, while willing to accept much greater health risks in their personal lives, demand zero occupational risk.

Non-epidemiologic decision making

In many hospitals today, healthcare epidemiology staff have become advisors to hospital administrators who ultimately make decisions regarding the logistics of infection prevention. And their decisions may not be purely based on science. They often have aversion to approaches that would appear to be out of the mainstream of what other hospitals are doing, even if that's suboptimal. In addition, infection prevention seems to be increasingly used as a public relations tool. If you don't believe that, do a simple Google search and you will find scores of press releases published in local newspapers from hospitals who have purchased germ-zapping robots. By the way, I believe that one of the best uses for a hydrogen peroxide vapor robot would be terminal disinfection of the Ebola patient room. Perhaps those hospitals who have invested in this technology should be the first to receive Ebola patients.

Paramilitarization of public health

In the run-up to the Iraq War, the Bush administration sought to engage the public health and medical communities in the war on terror. Much effort was devoted to preparations for bioterrorism. Who can forget the smallpox vaccine debacle? Preparedness was all the rage, and the Joint Commission couldn't resist jumping on that bandwagon.  Admittedly, some of the impacts of this were positive. For example, hospitals became more tightly linked to public health agencies and those agencies became much more engaged and proactive. But a new group of professionals emerged who are employed to make us prepared, and perhaps a little scared. A physician colleague who works in the IT world tells me that the constant fear mongering by IT security specialists is in part a job security tactic. So the folks who work in preparedness stand ready to help, perhaps in a more aggressive way than necessary this time.

Ok, anyone still surprised we've cranked it up to 11? I'm with Dan in hoping that we'll be able to dial it down to 8 this week.

Saturday, August 9, 2014

Dialing it up to eleven

While I was away on vacation, I did my best to keep up with the advancing Ebola outbreak in Africa (see Mike’s excellent summary post). I also joined a couple conference calls about the interim infection prevention guidance from CDC. I believe this guidance to be reasonable and consistent with the mode of transmission of Ebola, combining Standard, Contact and Droplet precautions with an emphasis on eye and face protection and use of additional barriers and precautions as required by the clinical situation (e.g. copious body fluids in the environment, aerosol generating procedures, etc.). I was also gratified to see some common sense interim laboratory guidance from CDC, guidance that included reassurance that
“When used according to the manufacturer’s instructions, EPA-registered disinfectants routinely used to decontaminate the laboratory environment (benchtops and surfaces) and the laboratory instrumentation are sufficient to inactivate enveloped viruses, such as influenza, hepatitis C, and Ebola viruses."
There’s only one tiny problem: nobody seems to be listening to this guidance. Like Nigel Tufnel, we’re dialing our responses up to eleven. The early returns from our infection prevention listserve favor airborne isolation, N95 masks, full Tyvek suits, anterooms for decontamination hose-down, etc. Similar returns from the clinical microbiology side included labs that didn’t plan to submit any testing to their main lab until they got Ebola testing results back, or requiring elaborate specimen decontamination protocols prior to any standard lab testing (some of which invalidate such test results). 

This reaction is predictable and understandable, given media coverage and the early approaches taken at Emory:
“Those working at Emory also can take comfort in that they have a unique place -- one of only four such facilities in the United States, according to Ribner -- to treat such a contagious disease…The isolation unit was created 12 years ago in conjunction with experts from the U.S. Centers for Disease Control and Prevention, which is based down the street. It features "special air handling," strict protocols on everything and everyone who goes in and out of a patient's room, and other measures to ensure that any potential dangers are contained.”

Combine this with the only images most Americans, including healthcare workers, associate with Ebola, and you can see how it becomes extremely difficult to recommend anything but the most stringent possible precautions.

The problem is that such precautions are wasteful of time and resources (invest in Tyvek, now!), and can interfere with patient care. As one example, most patients returning from the outbreak area with febrile illness (those meeting the Person Under Investigation (PUI) definition) will not have Ebola, but they may be very sick. If an overly stringent lab protocol prohibits or delays laboratory testing, substandard medical care may lead to adverse outcomes. Another concern—introducing healthcare personnel to new and unfamiliar forms of personal protective equipment without time for adequate training may inadvertently increase the risk for transmission. Do you know how to safely remove a full-body zippered Tyvek coverall without contaminating yourself? I don’t.

I wish I knew how to dial it down, maybe to 8 or 9, but I fear that the window for clear and consistent messaging may have passed. If only we could magically package all of the resources and person-power currently being applied by US hospitals in preparedness efforts and transfer them to West Africa, we’d be a long way toward containing this tragic outbreak.