The Consequences of a DMV Approach to Infectious Disease

One of the recurrent themes I reiterate when it comes to whatever infectious disease emergency the world is faced with is that much of the expertise of responding to these ever evolving threats resides in public health agencies. These agencies range in depth and expertise from the CDC at one end of the spectrum to a local health department at the other. While infectious disease management is really the raison d'etre of public health and are their core and original function, recent decades have seen public health agency's exhibit mission creep. Now public health agencies often balance the demands for developing a plan for tackling obesity with one for preventing the spread of tuberculosis. Such, in my view, distractions from their fundamental role deprioritize infectious disease in a risky manner. Last night, I gained another piece of data I added to support my position.

As someone who also trained in emergency medicine -- in addition to infectious disease and critical care medicine -- I try to keep my hand in the field with a few casual shift in my hometown hospital's emergency department. Being an infectious disease physician, however, I am always on the lookout for interesting infectious disease cases that I can pluck from amongst the myriad complaints that bring people to the ED.

Yesterday, I had that opportunity when I saw a patient recently returned from a Zika-laden area of the world who had symptoms entirely consistent with Zika. The case was uncomplicated and likely will be self-limited, as most Zika cases are. But, ever conscious of the epidemiological importance of diagnosing certain infectious diseases, I believed the patient merited confirmatory testing. Such testing is largely the province of the state department of health (though commercial tests are available) and, because of that, requires consultation to arrange for testing to occur.

Because it was after hours (infectious diseases are regularly not just 9-5 pathogens) , I was predictably frustrated with the state department's health response as it took some time to reach a person who could "authorize" the test, which was being performed almost exclusively for public health purposes as my treatment of the patient would not be impacted by the result of the test. Needless to say, an after hours inquiry in which one must navigate and bounce between telephone numbers with recorded messages and an answering service unable to effectively understand or triage the needs of a caller are the opposite of the nimble response needed to adeptly manage infectious disease emergencies. It is what one expects of the DMV.

To its credit, I did receive the information needed from professional and knowledgeable health department personnel but I would say that the trouble I incurred trying to obtain this information is likely something many physicians would not endure-- a dangerous situation that limits the ability to have full situational awareness of infectious diseases circulating. I am an unequivocal supporter of reporting infectious diseases with requisite import and can only imagine how many healthcare providers understandly do not wish to wade through the bureaucratic processes needed to ensure that appropriate testing and notification occurs. So, suffice it to say, the Zika case reports in the US are likely an underestimate. 

I'd like to think that this phenomenon would not occur so readily if the original focus of the department remained intact and their resources were not scattered so far afield from their original infectious disease mission.

Truth is Stranger than Fiction: Designated Survivor, Bioterrorism, and Elections

The bioterrorism scenario on last night's episode of ABC's Designated Survivor involved an attack with ricin specifically aimed at poll workers in an effort to derail Congressional election. While people who are not steeped in the history of bioterrorism may think this was just a far-fetched Hollywood fairytale, it was not. 

Over 20 years ago a similar plot was enacted successfully not in some banana republic but in the United States. The setting was a 1984 election in Oregon in which one of the issues was how a locality would handle a religious cult's (Rajneeshee) land holdings. In order to diminish voter turnout, salmonella was spread on restaurant salad bars sickening hundreds. 

It was not obvious that this represented a biological attack as poor food handling practices were how the event was initially described. Remeber that salmonella outbreaks are ubiquitous. Only after cultists eventually confessed was the actual etiology of the event uncovered -- underscoring how hard it can be to tell the difference between a natural and an intentional outbreak.

It would make a good movie.

 

The US: A 5.4%er in Infectious Disease Mortality

As nations civilize and become rife with sanitation, vaccines, health care providers that causes of death of the population will change. In this transition, infectious diseases became less substantial components of overall mortality as heart disease, cancer, strokes, and other conditions -- typically associated with longer life spans -- begin to became the major causes of death. Such has been the case in the US for quite some time. Indeed, the decline of infectious diseases after the advent of penicillin is what first gave rise to the need for a distinct group of physicians to develop specialized knowledge of what had become relatively rare illnesses.

A new paper. published in JAMA, attempts to quantify what proportion of deaths in the US can be attributed to an infectious cause. The verdict is that between 1980 and 2014 infectious diseases comprised 5.4% of the causes of mortality of the US. While the 5.4% number may seem relatively small there are a couple of important aspects of this statistic that merit consideration:

  • The revolutionary impact of antiretroviral treatment on survival rates of those infected with HIV
  • The rise of deaths from infections such as Clostridium difficile and West Nile Virus
  • The relative plateauing of deaths from pneumonia and influenza
  • The decline death rate from vaccine preventable illnesses

I wonder, however, if 5.4% is the true number as it was ascertained from death certificates which I have found to be pseudo-random in what is listed as a cause of death. Additionally, sepsis -- a final common pathway to death for many infections -- is clearly a major contributor to deaths, accounting for half of all hospital deaths. It is debatable whether sepsis, as a non-specific non-pathogen centric diagnosis, should be included however, strictly speaking, it is infectious disease-related.

Another important aspect of this research is understanding how low we can get with infectious disease mortality. There are several avenues for this and it is unclear from where the highest yield will emerge.  One strategy that come to my mind includes attacking the pneumonia/influenza death rate -- which comprises 40% of infectious disease deaths-- through a better influenza vaccine coupled to higher uptake of influenza and pneumococcal vaccines.

I think it is long since time the US aim for, join, and found the 1% club for infectious disease mortality. 

Multitudes R Us: A Review of Ed Yong's I Contain Multitudes

If I were to break the history of infectious diseases medicine into periods I would say that infectious disease has moved into the period of the microbiome. This period, I believe, will be characterized by major discoveries regarding the role of the microbiome not only in health and disease but also establishing the role of the microbiome and its constituent microbes in various physiological functions in virtually every living organism on the planet. 

I have found no better way to understand the full implications of the microbiome than the masterful science journalist's Ed Yong's I Contain Multitudes: The Microbes Within Us and A Grander View of Life

This book, which is almost impossible to encapsulate because of the plethora of valuable information it contains, is a tour of the world of life with special attention and focus devoted to the role that microbes play in every organism's life. While the role of the microbiome is very well-established with certain human infections such as Clostridium difficile, Yong moves much further than these topics and explores the role of the microbiome in life more generally moving deftly from humans to corals to frogs. Some of the aspects of the book that I found exceptionally fascinating were his detailing of the various roles of the Wolbachia genus of bacteria as well as that of Sodalis.  

After finishing Yong's book, I am increasingly thinking that maybe we should stop discussing genomes and microbiomes and move to discussing the holobiome instead for understanding the "multitudes" and how they interact with us and other organisms likely holds many keys to unraveling the myriad mysteries of biology that remain to be solved

 

Smog: What Lurks Within

The planet teems with bacteria in all niches imaginable, including the air we breath. Integrate this fact with the fact of the ubiquity of antibiotic resistant bacteria and it is not surprising that the air itself contains antibiotic resistant bacteria. A recent study, that the popular press has been reporting on, reveals that the smog (an amalgam of fog and particulate matter) of Beijing contains many antimicrobial resistance genes. 

Before anyone suits up in a gas mask before going outside (as if the air inside one's house is sterile), it is important to put the finding into context.

While the finding itself doesn't strike me as surprising, it does illustrate the magnitude and full scope of antibiotic resistance. I often emphasize that antibiotic resistance is a unrelenting process in nature that humans have exacerbated with injudicious use of antibiotics. Antibiotic resistance is how bacteria struggle and fight with other microbial species and everywhere you look resistance is present -- even in caves in which no human has set foot. It will always be present at some levels and that is why antibiotic stewardship that accounts for this fact and minimizes the acceleration of the process is crucial

What the implications are of this latest piece of research? I wonder if some of the community-acquired drug-resistant infections and colonization might be the result of acquisition from the air. This study noted the presence of antibiotic resistant genes -- not the presence of viable bacteria --- so follow up studies could attempt to cultivate antibiotic resistant bacteria from the air.