Thursday, October 30, 2014

Planning for the unplannable: What about next time?

A recent article in Forbes, written by Scott Gottlieb, began by observing that
The response by public health officials and local providers to the first case of Ebola diagnosed on U.S. soil has been marked by some tragic missteps. Mistakes have resulted in the avoidable secondary spread of the infection to healthcare workers. This is an appalling outcome to a crisis . . . But, sadly, it should neither be surprising, nor foretell a future marked by continued blunders.
As he suggests, I'd really like to think that the response to the events in Dallas will result in better ED and hospital care. It's important to learn from errors, and this seems to be happening: There's been a dramatic increase in infection control awareness since late September.

That seems like a good thing, but there's more to the picture. Alison Bruzek wrote an interesting piece for NPR last week on how, for hospitals, doing more on Ebola can mean less elsewhere. A passage from the article illustrates the point:
For infection preventionists, a normal routine includes "Looking at the lab results[.] [W]e're looking at what new patients maybe came onto a unit, we're taking calls from the unit, [and answering questions like] 'What do you think I should do about this particular thing?'" says Linda Greene, an infection prevention manager and member of APIC's regulatory review panel. But now, Green says, if the infection preventionist is working on training with personal protective equipment for Ebola, their other tasks aren't getting done as promptly or efficiently as they could be. As a result, Greene [says] the fear is that they'll "miss red flags" for patients with the flu or antibiotic-resistant bacteria.
How can this be avoided? It's difficult for many reasons, including that hospitals, financially speaking, are zero sum propositions: Annual budgets govern allowances for departments. A previous blog discussed the trade off between different infection prevention activities given a constant budget through a fictional story. Bruzek's article highlights how focus here might lead to shortcomings there, all things being equal (i.e., budgets and resources being constant), in a real situation.

One might think that hospitals should simply do a better job of planning for contingencies like the Ebola preparations in which they are now engaged. Perhaps they could, but it's not necessarily simple; budgetary contingencies are usually for things that are random but can be conceived and planned for. Nobody forecast this Ebola event or the implications for US healthcare, and no hospital could rightly be expected to have included Ebola preparations in their fiscal year planning.

Moreover, this situation may have been unplannable. While analyses of public health threats, including bioterrorism, have considered a broad range of issues, I don't have the sense that anyone truly anticipated the extent of the hospital, media, or political issues encountered in the US recently. Nonetheless, the need to prepare for complex unexpected events cannot be denied.

So how do we plan for the unplannable? To address the issues mentioned in Bruzek's article would require specialized human resources and the funds to engage them on a surge basis, in addition to money for PPE. Planning for the availability of such human, material, and financial resources is not easy when they are required randomly, rarely, and -- as in this case -- widely. It's important for public health researchers, professional organizations, and trade groups to study and address such issues, because if there's one thing nature has taught us, it is that there will be a next time.

Thursday, October 23, 2014


File:Expression of the Emotions Figure 20.pngSome people in the US have absolutely panicked over the threat of Ebola at home. To cite but a few examples:
  • A Portland, Oregon, high school canceled a visit by African students, citing concerns about Ebola. The 18 visiting students came from Republic of Congo, Niger and Ivory Coast, none of which currently have reported cases of Ebola, according to the WHO.
  • Two children who recently moved to the US from Rwanda are being kept home from school after parents at an elementary school in New Jersey voiced concerns. Rwanda is in East Africa, over 2,500 miles from the West African areas where Ebola virus is currently circulating.
  • An assistant principal at a North Carolina middle school has to spend 21 days working from home when she returns from a mission trip to South Africa, by order of the school board. The chairperson of the school board explained why: "It’s not that we think that she poses any type of risk, but it's public perception here that we're concerned about.
More examples are described in a recent CNN article, which also notes that:
This is getting ridiculous. While the threat of Ebola is very real in Africa, the paranoia it's generated in the United States is unreal.
Many baseless actions are being taken out of "an abundance of caution", and it's not only in the US: A recent article by Andrew Higgins describes similar behavior in Europe.

While listening to the radio while working today, it struck me how someone having a case of air sickness on a commercial jetliner now makes the national news. Perception of risk is a notoriously sticky subject, but perhaps it's a good time to begin a conversation on how to educate people better on the topic. Could some basic elements of risk assessment be taught, for example, in high school?

(image source: Wikipedia)

Saturday, October 18, 2014

Fear, Ebola, and the plague doctor's outfit

An earlier post mused that, in some ways, modern healthcare workers in contact precautions might appear as the plague doctors did in the Middle Ages to their febrile, terrified patients. The imagery of the plague doctor's outfit has survived centuries in association with a horrific event responsible for significant death and social disruption. Today, the doctor's outfit remains a powerful symbol of desperate times.

While the current epidemic of Ebola virus disease is unlikely to have the depopulating effect that plague did in the 1300s -- the Black Death is estimated to have killed up to 60% of the European population at the time -- the deadliness of this virus as it circulates in Western Africa must produce a fear similar to that of the Black Death in the Middle Ages. It makes me wonder if, years from now, pictures of doctors and nurses in Ebola personal protective equipment (PPE) -- the garb healthcare workers must wear to care for patients -- will conjure up similar reactions to those of the plague doctor's outfit.

Think of the similarities. If the case fatality rate (CFR) of plague in the 14th Century was similar to that of plague in the US between 1900 and 1941 (i.e., in the pre-antibiotic era), the CFR of the Black Death could have been over 60%. The CFR of Ebola in West Africa is currently estimated to be near 70%. Probably due to this high CFR during the Black Death, people were often deeply skeptical of doctors, as as Giovanni Boccaccio  describes in The Decameron:
Which maladies seemed set entirely at naught both the art of the physician and the virtue of physic; indeed, whether it was that the disorder was of a nature to defy such treatment, or that the physicians were at fault - besides the qualified there was now a multitude both of men and of women who practiced without having received the slightest tincture of medical science - and, being in ignorance of its source, failed to apply the proper remedies; in either case, not merely were those that covered few, but almost all within three days from the appearance of the said symptoms, sooner or later, died, and in most cases without any fever or other attendant malady . . . 
As we have read in this event, distrust of healthcare workers in Western Africa has led to attacks on doctors, though this sentiment may partially stem from historical events. Indeed, serious issues with healthcare in this region are nothing new.

Of course, there are important differences between bubonic plague in the Middle Ages and Ebola in Africa today as well. Plague is caused by a bacterium whereas Ebola virus disease has a viral etiology; Yersinia pestis is carried by domestic rodents and vectored to humans by fleas whereas Ebola virus is directly transmitted between humans; et cetera. Perception is reality, however, and one overarching public perception is proving a difficult to alter: Ebola is terrifying. Ebola PPE is a modern plague doctor's suit, a tangible symbol of fear, a fear that we have but to turn on any newscast to see spread.

I feel strongly that we must never forget the human dimensions of disease. Physiologically speaking, Ebola virus disease in Homo sapiens is increasingly well understood, but the impact of the disease on the human condition is perhaps less so. If we are to control the spread of Ebola virus, we must understand this better; it seems clear that we don't. Fear and panic only make the situation worse. We must control the fear.

(image source: Wikipedia and WHO)

Saturday, October 11, 2014

Ebola versus influenza and some thoughts on screening

My colleague Eli Perencevich wrote an interesting blog this week in which he discusses airport screening. He points out that some of the discussion surrounding travel restrictions and Ebola are related to ideas from (and models of) epidemics of respiratory viruses, including the 2009 H1N1 pandemic. In the post he highlights some of the important differences between Ebola and influenza:
. . . Ebola is slower moving, has a much longer incubation period (especially compared to the duration of a transcontinental flight), and is not contagious before symptoms develop. What does this mean? It means that if Ebola was as infectious as influenza, millions would have already died - apocalypse. It also means that since Ebola is not transmissible during its long incubation period, it may be possible to quickly isolate patients when symptoms develop. Thus, airport screening on exit or entry could limit transmission and perhaps through early diagnosis allow Ebola infected patients to receive life saving treatment more quickly. 
Later in the post he highlights the need for mathematical model-based analysis of the impact of specific Ebola screening programs. I recommend reading the blog.

As I mentioned in a comment to the piece, in addition to incubation period, it's useful to consider the serial interval (the period between infection and transmission; sometimes also referred to as the generation interval or generation time) and basic reproduction ratio (R0). As discussed before, estimates for R0 for Ebola in this event are similar to estimates of R0 for pandemic influenza events. White and Pagano estimate the serial interval for a 1995 outbreak of Ebola in Congo to be 5.4-7.6 days and the WHO Ebola Response Team estimates the serial interval for the current epidemic to be near 15 days. By comparison, estimates of the serial interval for the 2009 pandemic of influenza fall in the range of 2.5-3.0 days. Ebola has much longer serial intervals than does influenza.

What do we take away from this? One thing is that the serial interval is important for understanding the speed of spread. Perencevich observes that
. . . the first case of Ebola is thought to have occurred 307 days ago on December 6th in a two-year old boy. Since that time there have been an estimated 8,032 cases (granted these could be underestimates). If you compare a similar 307-day period for 2009 H1N1, April 12, 2009 to February 12, 2010 CDC estimated that between 42 million and 86 million cases occurred in the US with a mid-level estimate of 59 million people infected. Think about that -- 7,300 times more cases of H1N1 using the mid-level estimate during the same 307 days.
It's clear, then, that equating influenza and Ebola on the basis of R0 alone is misleading. Thinking of R0 as a reproductive factor for each generation of infection (at the beginning of an epidemic in a susceptible population) and the serial interval as how rapidly generations of infection occur, however, it becomes clearer that the much shorter serial interval of influenza is related the explosive emergence of influenza cases in 2009-10 relative to Ebola in 2013-14, despite the similar R0 values. It's more complex than this in reality; Wallinga and Lipsitch present a detailed mathematical treatment of how generation intervals shape the relationship between epidemic growth rates and reproductive numbers, and Lipsitch et al illustrate, within the context of SARS, how incubation period, serial interval, and epidemic growth rate combine to produce estimates of R0.

Another thing to ponder is that longer serial intervals can, depending on the length of the incubation period, give more time to institute control measures. On the one hand, the long serial interval relative to incubation period in the case of Ebola may suggest a higher likelihood of detecting an infectious traveler in an airport than there is for influenza. On the other hand, the extremely low incidence of Ebola in passengers must also be considered; it may not be an efficient activity to devote resources to.

I agree with Eli that mathematical models can help shed light on such questions. Perhaps such models have been published, I admit to falling behind on the mathematical epidemiology of Ebola results in the last two weeks. 

(image source: David Hartley)

Sunday, October 5, 2014

Ebola, EHRs, and the difficulty of communication

A quick update to a point discussed in the last post. On Thursday night, the Dallas hospital treating the patient suffering from Ebola virus disease explained the mix-up over his travel history. A news release on the hospital's website reads:
 . . . Protocols were followed by both the physician and the nurses. However, we have identified a flaw in the way the physician and nursing portions of our electronic health records (EHR) interacted in this specific case. In our electronic health records, there are separate physician and nursing workflows.
The release then explained that the flaw had been remedied, by relocating the "travel history documentation to a portion of the EHR that is part of both workflows" and to "specifically reference Ebola-endemic regions in Africa".

The promptness of the communication was reassuring and helpful, and suggested that an analysis of the situation had been undertaken promptly, a cause of the error identified, and action taken to fix it. But 24 hours after the news release, a perplexing clarification was posted:
We would like to clarify a point made in the statement released earlier in the week. As a standard part of the nursing process, the patient's travel history was documented and available to the full care team in the electronic health record (EHR), including within the physician’s workflow.

There was no flaw in the EHR in the way the physician and nursing portions interacted related to this event.
It's difficult to interpret the dissonance of these two releases, and I think they highlight a hugely important in hospital care: the challenges of effective communication between all members of the healthcare team.

Joyce Frieden wrote a very nice essay on the Dallas episode (published before the hospital's "clarification"), which I recommend reading. One passage describes some of the challenges to effective communication in the clinic:
Although the EHR could have been configured to import the nursing notes -- or at least their key items -- into doctor's notes automatically, "I'm sure some doctors would say it would be a bad idea because it would fill their notes with stuff they're not interested in," he [Dr Dean Sittig] continued. "So that's the culture of the two professions not respecting what each profession does. Whereas before docs had to flip through the nurse's notes to get to where they wanted, now they're on a separate tab. The flaw was that they weren't pushed into the doctor's face."
The importance of effective communication, from the perspective of the Magnet® process, has been discussed by Swanson and Tidwell, who note that 
One characteristic of exemplary professional practice is meticulous attention to communication processes. . . . This use of SBAR has created a standardized approach to information sharing. It has created a shared mental model for effective information transfer by providing a standardized structure for concise, factual communication among clinicians, whether it is nurse-to-nurse, doctor-to–doctor, or nurse-to-doctor communication. It is now used to ensure that patient information is consistently and accurately communicated, especially during critical events, shift handoffs, and patient transfers between levels of care. [Emphasis added.]
Apparently this critical nurse-doctor communication and information transfer didn't occur during the patient's hospital visit on September 26th.

Effective communication is a human process. Software should be used to improve that process, not replace it.

(image source: David Hartley)

Friday, October 3, 2014

Ebola and the cult of vitamin R

File:FEMA - 18213 - Photograph by Robert Kaufmann taken on 10-25-2005 in Louisiana.jpgThis week saw the appearance of Ebola virus disease in a Liberian visitor to the United States. Active transmission here is not expected and public health authorities have done extensive contract tracing. Fifty individuals who were potentially exposed to the virus are being monitored and a small number are in isolation

First, a brief description of the episode. A man who had direct contact on September 15th with a woman suffering from advanced Ebola virus disease in Monrovia, Liberia, traveled to Dallas, Texas, to visit relatives. He flew from Monrovia to Brussels on the 19th of September and took a connecting flight to Washington DC before catching a final flight to Dallas, arriving on the 20th. He was screened for fever and exposure at the airport before departing Liberia; apparently, his answers to a screening questionnaire were inaccurate. After arriving in Dallas he remained asymptomatic for several days and began suffering symptoms on the 24th. On the 26th he presented to the hospital. (Note: some news accounts report the date as the 25th.) At this first visit he was evaluated, prescribed antibiotics, and sent home to the relatives with whom he was staying in Dallas. He subsequently deteriorated and was transported to the ED by ambulance on the 28th. The positive test for Ebola virus was received on the 30th.

Many details about this event are unsettling. To me, especially disappointing is that the man's travel history was not a factor in the clinical diagnosis on the 26th, although a nurse was informed that he was visiting from Liberia. The nurse entered the information into the electronic health record (EHR), following protocol, but that didn't trigger suspicion. The hospital has since clarified why: There are separate physician and nursing workflows, and patient travel history did not automatically appear in the physician's standard workflow. The doctor never saw the information.

I think it's also interesting that the man was prescribed antibiotics for what turned out to be a viral illness. In a sense, this is a familiar story: change the name of the virus and it's a scene that occurs daily in many clinics and office visits. It seems ironic that, a week after the White House released its National Strategy for Combating Antibiotic-resistant Bacteria, this physician-patient encounter resulted in the apparent inappropriate prescription of antibiotics. As the National Strategy tells us, 
. . . a growing body of evidence demonstrates that programs dedicated to improving antibiotic use, known as "antibiotic stewardship" programs, can help slow the emergence of resistance while optimizing treatment and minimizing costs. These programs help providers prescribe the right antibiotic for the right amount of time and prevent prescription of antibiotics for non-bacterial infections. It is imperative that such programs become a routine and robust component of healthcare delivery in the United States. (emphasis added)
To be fair, the man may have had a bacterial infection at the first hospital visit, in addition to the unsuspected Ebola virus infection. We don't know; it's a matter of his private health record. However, I am reminded of how a physician colleague once described the pervasive inappropriate, and often rushed, use of antibiotics,
It's a common problem. Patients present with vague complaints that are plausibly due to bacterial infection and there is a very low threshold for prescribing antibiotics. The patients often request or insist on it, and it often seems harmless to acquiesce. In fact, many doctors view prescribing them as a protection mechanism in case there is an infection or one develops. It's so common that in many clinics and EDs ceftriaxone is referred to as "vitamin R".
Perhaps the antibiotic prescription dimension of the encounter on the 26th is all too understandable.

One can hope that a thorough, transparent investigation and analysis of this entire episode can produce helpful knowledge on how to harden healthcare systems for routine healthcare as well as extraordinary events like this one. In the meantime, the CDC has produced clear guidance for evaluating patients with a history of traveling to epidemic regions.

Acknowledgement: The title is inspired from a Medscape Connect item entitled "The cult of Vitamin R", which no longer appears to be available online.

(image source: Wikipedia)