Saturday, June 13, 2015

MERS as (another) messenger of prevention

It's hard for me to know how to interpret the MERS situation in South Korea. At a high level, a recently recognized viral respiratory pathogen has traveled halfway around the world and is causing morbidity and mortality in a small section of an immunologically naive population. It appears to be associated with hospitals. What do we take away from this? Lessons will be learned when the event subsides and people study what happened, but to me, MERS reminds us that outbreaks of pathogens for which there are no vaccines or drug therapies underscore the importance of prevention.

When possible, preventing pathogens from physically reaching or entering a host by respiratory, percutaneous, alimentary, blood et al pathways is preferable to relying on pharmaceutics. Drugs tend to be complex and costly to develop, can take a long time to enter the marketplace, and -- especially in the case of antibiotics and antivirals -- they can become obsolete over time. Moreover, drugs are often toxic to the patient. Prevention is applicable in situations when appropriate drugs don't exist (e.g., for newly emerged pathogens), when it isn't possible to administer drugs in a timely manner, or when patients cannot tolerate them. 

Consider two anecdotes related to the spread of MERS virus in South Korean hospitals. As described by Choe Sang-Hun, it appears that the index patient in the South Korean event had "coughed and wheezed his way through four hospitals before officials figured out, nine days later, that he had something far more serious and contagious." Furthermore, ED wait times in Korea can be extraordinarily long by US standards. Another patient, who waited two-and-a-half days in the emergency department before a hospital bed became available, infected 55 additional individuals during their wait. Apparently, 2.5 days isn't an unusually long waiting time in some Seoul hospitals. 

Applying effective prevention measures to patients suspected of infection is the only way of stopping the chain of transmission in such environments. Unfortunately, it is unclear how to achieve good infection control for MERS and a range of other pathogens. Eli Perencevich described the issue clearly, as usual, in the Controversies in Hospital Infection Prevention blog recently: 
. . . we don't actually know how to achieve good infection control for MERS and the other diseases he [Tom Frieden] mentioned [measles, DR-TB, SARS, Ebola]. If only we invested in studies to understand how to best implement PPE in these [hospital] settings. One could imagine improved PPE technology, refined PPE donning and doffing algorithms and enhanced environmental cleaning as potential targets for future studies examining optimal protection from MERS. Not coincidentally, many of these are the same targets that Mike, Dan and I mentioned in our Ebola+PPE editorial several months ago. If we invest in infection prevention technology and implementation research, our health care system will be safer regardless of the pathogen du jour.
And that's the point that MERS makes me think about. Yes we need antimicrobials and vaccines that work against specific pathogens, of course we do, but developing such drugs is a major effort. Biochemical pathways must be understood, pathogen life histories and survival strategies must be elucidated, and the host response must be characterized among many, many other things. Doesn't it make sense that research on pathogen-agnostic approaches to prevention, which don't require such specific and complex information, might be simpler and broadly applicable? 

Investing in research on infection prevention approaches, and how to implement them sustainably in realistic clinical environments, would pay benefits far beyond helping to thwart the spread of exotic and newly emerged pathogens. We may learn how to better control and prevent the usual suspects of hospital associated infection, which, afterall, are responsible for a tremendous burden of disease day in and day out.

(image source: Wikipedia)

Wednesday, June 3, 2015

Vaccines, cancer, and science communication: Oh my!

Tara Haelle, writing for NPR recently, tells how a university press release, inaccurately entitled "Study explains how early childhood vaccination reduces leukemia risk", was covered widely in the press last month. The release attempted to explain newly published research carried out, in part, at UCSF. She describes how conversations with the senior author of the study failed to temper some questionable passages in the press release, and how follow-up with other researchers expert in vaccines helped to provide clarity. It's a good article and I recommend reading it. The bottom line, she suggests, is to always be skeptical of press releases.

That's certainly sage advice. I don't want to go into the details of this particular case; Haelle does that very competently, as do others, and it's easy enough to check the face validity of the claims of the release and author interview yourself via the SEER Website and FDA vaccine license time lines. Rather, I want to step back from the details and think about the episode more broadly.

This is a case of a group of scientists carrying out research that passed peer review and was published in a prestigious journal. When such a study is published, universities understandably want to make the presumed important information available to a broader audience. The titles and topics of many research articles probably won't draw the attention of casual readers, so universities have media relations teams that work with researchers to write press releases and help investigators interact with the press. One danger of this, and again it is understandable, is the potential for over simplifying and overselling research in order to make it accessible and relevant to the public.

It can also lead to a misunderstanding of the process of discovery. Medical science is a fluid, dynamic endeavor in which knowledge emerges iteratively, often triggered from conflicting results. Rarely does one study show anything definitively. In fact, many findings described in peer-reviewed studies are refuted later by the findings of other peer-reviewed studies. It has been argued that most published research findings are false, and recent evidence suggests that an alarming number of published results aren't reproducible. It reminds one of a quote attributed to physicist Wolfgang Pauli,
I don't mind your thinking slowly; I mind your publishing faster than you think.
Regardless of publication rates (and the pressures leading to those rates), knowledge emerges as conflicts are resolved, which can take years or even decades. It's unclear whether this is widely understood by those consuming medical and scientific information via the popular press. We need to think about how to communicate both new scientific findings and the process of science to the public more effectively. 

(image source: SEER)