Feces per Burrito: More Important than Calorie Count

Oddly, or maybe not if you follow foodborne outbreaks, both Chipotle and Qdoba are in the midst of food-borne outbreaks. In the case of Chipotle it is the O26 strain of E.coli to blame while Qdoba has been linked to cases of typhoid fever.

Both of these illnesses share something in common other than the burritos they apparently are lurking within: they are both transmitted through the fecal-oral route. What that means, in terms a kindergartener can understand, is that poop gets into the food. This can happen with suboptimal food handling in a restaurant (which happens to be the case with Qdoba with its own version of Typhoid Mary) or at some earlier point (e.g. during harvesting). 

In my view, E.coli O26 -- which elaborates shiga toxin, a cause hemolytic-uremic syndrome which can progress to kidney failure and death -- is a much more serious outbreak. Typhoid, though deadly in prior decades, is treatable with antimicrobials and because, in this case, the source is known will likely be quickly contained.

What is special about burritos and other similar foods is that they are comprised of myriad ingredients -- just imagine how many herbs, spices, and vegetables are in salsa. These ingredients can come from multiple different suppliers which magnifies the chance of contamination occurring. 

The industrialization of food is an enormously beneficial development that is hugely economical and has driven food prices down. This trend allows the average person the ability to sample exotic cuisines from all over the world. The risk, which is present with all types of food, is that contamination may occur and illnesses such as these can occur highlighting the need to be vigilant once these outbreaks are identified.

Yes, I am a Chickenpox Doctor

Today in the hospital elevator a patient asked me what kind of doctor I am. I replied that I am an infectious disease doctor and the patient replied: "Oh, like chickenpox". 

His reply was accurate but prompted me to think about the fact  that most of the general public's knowledge of my field has to do not with the day-to-day MRSA, C.diff, prosthetic joint, injection drug use related, and diabetic foot infections I am mired in, but with acute contagious diseases such as chickenpox. 

During Ebola and the 2009 H1N1 influenza pandemic the role of infectious disease physicians and the reliance on our expertise by the media, the public, and colleagues was evident. In the clinical workday of an average infectious disease physician, it can be easy to forget that role amongst the bureaucratic processes, the haggling with cardiologists, the frustration with the hospital pharmacy, and the mundane infections one is consulted on.

What makes it worth it, for me, is that amongst all the ordinary causes of pus and infection a zebra may be lurking and it is a supreme intellectual challenge to spot it. To put it simply, I love solving puzzles.

Chickenpox, thanks to vaccination, has become such a zebra in the America -- so yes, I am a chickenpox doctor.

I wear the label proudly.

Taming Wild Polio Virus

There was much attention devoted to recent changes in the global polio eradication campaign when it was announced that vaccination against type 2 polio virus will cease in April 2016. This change was prompted by the eradication of this strain of the virus from the planet, leaving just type 1 and 3 left. However, the removal of type 2 polio vaccines is likely a response to other issues as well.

Polio eradication is currently being accomplished using the live Sabin oral polio vaccine which has the capacity to cause vaccine-derived paralysis in rare cases. These vaccine derived paralysis cases are almost always the result of the type 2 vaccine strain and with wild type 2 polio virus no longer a threat, the risk-benefit analysis of continued vaccination against type 2 has become altered.

Overall I think this is a good development and will make polio eradication more likely and the vaccine more palatable to the population who, because of the rarity of polio, may fear the risks of vaccine-derived paralysis.  

Wild polio has found its last refuge in just 2 countries -- Afghanistan and Pakistan -- while vaccine derived paralysis has been noted in several countries. So long as the live vaccine is used, the risk of vaccine-derived paralysis will be present.

However, a larger issue which lies behind the entire program, is the lumping of cases of vaccine derived paralysis with wild polio cases, a practice that has always struck me as problematic, especially given the use of the Sabin vaccine (which is considerably cheaper than the inactivated Salk vaccine) for which the risk of such cases will always be non-zero. 

If planetary eradication will only be declared once polio vaccine-derived cases are gone, the world will be waiting considerably longer. Eradication of wild polio virus is the real goal we should be focused on.

Does the GSK Malaria Vaccine Change Things?

Many people might mistakenly believe that because of the development of the first licensed malaria vaccine, GSK's Mosquirix (RTS,S), its rollout and implementation will be a simple feat. However, this is far from the truth. As wily a pathogen as malaria -- which has killed half the humans that have ever lived -- shouldn't be expected to go down so quietly.

Make no mistake the RTS,S vaccine is an important step forward and its development, which represents the 1st licensed vaccine for a parasitic disease, will add to the armamentarium of anti-malaria control measures. The problem, however, is that the vaccine's efficacy after the required 4 doses is only 40%. 

More recent data shows that this 40% figure might slip lower when the malaria parasite's penchant for mutation is taken into account. In a study of over 4500 vaccinees, the efficacy of the vaccine slipped to about 33% when there was a mismatch between the malaria parasite's circumsporzoite C-terminal and the corresponding vaccine component giving rise to the idea of vaccine-resistant malaria. 

This puts malaria control personnel into a difficult situation. How does one allocate funds with a somewhat protective (but limited) vaccine in the mix? Should less emphasis be placed on indoor spraying? Bed nets? Will the vaccine instill false confidence in the population prompting them to be less compliant with insecticide treated bed nets which unequivocally work.

All are difficult questions that will require a lot of thought. 

Explaining American Biodefense

In lectures I give on biodefense, biological warfare, and bioterrorism I always include a discussion of General George Washington’s prescient action to variolate (no vaccine existed at that time) troops facing the British Empire who might seek to use smallpox as weapon.  That was the real beginning of biodefense in this nation and through the 2 and half centuries since, it has morphed and evolved substantially.

The University of Sydney's Frank L. Smith III’s American Biodefense is a great addition to the scholarly works on biodefense. In his book, Smith develops a powerful explanatory principle that explains the seeming paradox of civilian biodefense being much more extensive than military biodefense. What Smith convincingly shows is that organizational frames of reference set the context for how the Department of Defense (DoD) and the Department of Health and Human Services (HHS) successfully integrated biodefense into their respective missions.

The DoD, Smith argues, is dominated by a kinetic frame of reference that is best exemplified by guns, bombs, and missiles (i.e. things that are propelled through the environment and impact a target with immediate consequences). HHS, with its constituent agencies of the NIH and the CDC, by contrast use a biomedical frame of reference.

Smith shows that once certain thought leaders such as Nobel Laureate Joshua Lederberg and D.A. Henderson convincingly proved in the early 1990s how biodefense and emerging infectious diseases were inextricably intertwined, it provided a path for HHS to integrate biodefense activities into their mission—especially when the threat became more imminent in the late 1990s.

Smith, with ample evidence, illustrates that DoD’s kinetic framework led to the inaccurate lumping and stereotyping of chemical and biological weapons together. Such a package deal ignores crucial differences, compromising certain preparedness activities that must be fully informed by the specific threat faced (this is not meant to criticize all-hazards preparedness activities which exploit true commonalities between varied threats). Also, because of this inherent deficiency, when biodefense became an issue for military operations it often prompted a scramble for resources such as during Operation Desert Storm.

For those interested in the field of biodefense, Smith’s book provides an important explanation for how American biodefense came to be structured the way it is and a path for optimizing it in the future. As the threats have not diminished—and are arguably higher—incorporating Smith’s ideas will be an important component of enhancing preparedness and resiliency.