Unsolved "MERSteries"

The announcement of the 2nd domestic MERS case today is not surprising and doesn't represent a major change in the pattern of cases. This case, like the one before it, is in a traveling healthcare worker and its detection reinforces the importance of astute clinicians armed with the knowledge and tools to detect emerging viruses.

However, in light of this case, lingering questions should be revisited given the smoldering nature of this 2 year plus outbreak.

Do super spreaders exist?

The most dramatic feature of SARS was the existence of super spreaders. These Typhoid Mary like individuals were responsible for much of the global spread of SARS. With MERS however, evidence of super spreaders has not been definitively established although events suggestive of such spread exist. For example, in Abu Dhabi there is an case patient who may have been responsible for secondary spread to 27 additional cases. It is unclear, according to the WHO (at this time), whether these were all linked transmission events or from non-human sources. Additionally, the Al Hasa outbreak detailed in the NEJM is also suggestive. 

I think that for all infectious diseases, super spreaders likely play a major role and MERS will turn out to be no different. 

Is This a Public Health Emergency of International Concern?

The International Health Regulations provide WHO with a mechanism to declare a public health emergency of international concern (PHEIC) when events reach a certain threshold. The WHO is convening a meeting tomorrow to determine whether MERS meets that criteria. I think this is a difficult decision because, in a way, MERS has met this criteria over the last 2 years and nothing fundamentally different has occurred (granted the uptick in cases). Prior meetings have not resulted in such declarations.  However, a PHEIC declaration may provide an impetus to countries with cases to provide more information about cases and the means by which they were infected. 

Little Pink Houses and MERS in Indiana

The just revealed news of an imported MERS (Middle East Respiratory Syndrome) case in Indiana--the first in the US--is not surprising. 

MERS has been simmering for 2 years and importations have occurred to several countries, including the UK. 

In this case, an infected healthcare worker (not surprisingly) traveled from Riyadh to London and on to Chicago. The patient then boarded a bus to Indiana.  

Although MERS has a case fatality rate of 30%, this patient appears to be not critically ill. Important actions in the coming days will include searching for secondary cases.

This case illustrates 2 important things:

1. It's a small world and infections on one side of the globe can appear on the other with no border restriction string enough to stop it. 

2. Astute clinicians are crucial. From what I've read, the patient's travel history tipped off physicians who ordered the appropriate tests. 

MERS occurring in the US was something that was expected and planned for--remember 8 SARS cases occurred in the US as well.

To Catch a Virus You Need A Special Mitt

I just finished the book To Catch a Virus. This book is focused on the developments in diagnostic virology that have shaped the way modern medicine confronts viral infections. What is most attractive about this book is that it details the discovery in a chronological fashion stressing the conceptual links between discoveries. For example, the development of PCR testing is handled in a manner in which one is able to see the progression from Oswald Avery to Kary Mullis without difficulty. Additionally, the book stresses the inductions made by various investigators providing a treasure trove of material for historians and philosophers of science. I highly recommend the book.

Why are Lice and Scabies Scarier than MRSA, C.diff, and VRE?

In the realm of hospital infection control there is a constant struggle to raise compliance rates with contact precautions. These measures are instituted when a patient harbors an organism that poses a transmission risk that is deemed to pose too great a threat to others in the hospital. MRSA, VRE, and C.diff are the big three but other conditions such as active tuberculosis and influenza also require isolation precautions. 

In most of these cases, contact precautions are considered burdensome and often result in less healthcare contact with such patients as healthcare providers eschew donning the gown and gloves required to comply with hospital regulation. 

However, 2 pathogens unequivocally prompt full compliance and when you see doctors and nurses meticulously ensuring their personal protective equipment is being worn appropriately you can be sure one of these two pathogens are present. 

It's not MDR-TB or measles that merits such mindfulness, but lice and scabies! 

It strikes me as paradoxical that such minor and easily treated pathogens strike fear in the heart of healthcare providers at such a momentous scale. 

Maybe a continual epidemic of lice, co-infected those with MRSA, C.diff, and VRE, is all that's needed to ensure compliance with infection control.

It's Elementary, Anthrax is Not Contagious

I like detective stories and detective work. That's why I love infectious diseases so much. Sherlock Holmes is probably the most famous literary detective archetype of all time and I enjoy reading Sir Arthur Conan Doyle's (who, by the way, was a physician) tales of his and Dr. Watson's adventures.

In that same vein, I enjoy watching the CBS program Elementary which portrays a modern day NYC-set version of Holmes and Dr. Watson. Last week's episode, which I was especially looking forward to, was focused on a death of a man from anthrax and the subsequent threat of its use in a mass casualty setting. 

One glaring factual inaccuracy, however, detracted from my viewing pleasure: on two occasions anthrax was mentioned in connection with quarantine. 

Quarantine, a measure that is scarcely used, is the exclusive province of communicable (i.e. contagious) diseases.

Anthrax is not contagious and the mistaken belief by the public that it is can pose problems during actual events, hampering response and needlessly causing unwarranted panic.

For example, as a medical student doing an ER rotation in New York City during October 2001, at the height of the Amerithrax attacks, I was "locked" down in an ED in which someone exposed to white powder presented. Predictably, no one would believe the medical student (albeit one that was a burgeoning ID physician) that anthrax was not communicable.

Anthrax does a lot of bad things to people but it doesn't spread between them.