Giving the Rectal Thermometer its Due

One of the cardinal features of many infectious diseases is the presence of fever. Fever, usually defined as a temperature exceeding 38.3 degrees Centigrade (100.94 degrees Fahrenheit), is a defense mechanism employed to stifle the growth of microbes who prefer to grow at lower temperatures and augment the immune system which heightens its activities at higher temperatures. 

Fever also has a major diagnostic role as it is used to discriminate between those who are more ill and those who are less ill. Fever is also part of the criteria for employing the concept "systemic inflammatory response syndrome" to a patient--which can trigger an extensive evaluation for an inciting infection.

With that context, it becomes clear that accurately determining if fever is present in a patient is an important task. Sometimes fever can be obvious and felt directly by touch, however tactile temperature taking is fraught with error therefore thermometers are employed. While it is well known that peripheral temperatures obtained in the mouth, ear, arm pit or forehead can be inaccurate and subject to manipulation (think of the school child who sticks a thermometer in a hot liquid before putting it in his mouth) they generally are the primary means of temperature assessment employed in healthcare settings. The gold standard of temperature measurement is more invasive and would involve measuring the temperature of the blood, the bladder, the esophagus, or the rectum directly. 

Rectal temperatures, being the least invasive of the three, is employed variably to determine temperatures. Usually small children and critically ill adults may have their temperature measured in this manner. A new study, however, provides evidence that this form of temperature measurement should be employed more liberally if accurate temperature measurement will make a difference in clinical management. 

In this study, which was a systematic review and meta-analysis, 75 studies were pooled and revealed that peripheral thermometers level of agreement with central thermometers was unacceptable and could be off by 1-2 degrees Centigrade at extreme temperatures (higher or lower). The sensitivity for detecting fever, furthermore, was just 64%--not too much better than flipping a coin. Specificity, meaning the reliability of a peripheral thermometer's detection of a febrile range temperature, was good at 96%. Translation: if your oral thermometer detects a fever, it is likely a real fever but if it reads normal, fever may still be present. 

To me, the results of this study should lower the threshold for obtaining a rectal temperature in those patients in whom the result would change management (after a peripheral temperature is reported as normal). This does not mean that every parent or grandparent should subject children to routine rectal temperature measurement because in that setting -- an ill-appearing child -- temperature adds little to the treatment (fluids, acetaminophen, ibuprofen). The other implication is the need to better calibrate peripheral thermometers prior to use and the need for innovation in this market to spare all our rectums.

Living Weapons: A Scholarly Analysis of Biodefense

In many ways the field of biodefense is young and still developing a robust amount of scholarly materials from which the foundations of the discipline will develop and new work flourish. There are, however, several books which, in my estimation, are worthy of being described as foundational in their approach.  I read almost everything in this field and usually find my knowledge deepened and better integrated by the process so each latest book is progressively less impactful. George Mason University's Gregory Koblentz's Living Weapons: Biological Warfare and International Security (2011) is one such book that bucks the trend in a good way and is a book that I highly recommend to those in the field.

Koblentz's book is a comprehensive overview of the field of biological weapons that is not a mere cataloging of the pathogens and the history. The book provides extensive analysis of the field and is especially illuminating when it comes to the problem of intelligence gathering in this realm. This, to me, was the chief value of the book.

Using the historical examples of biological weapons programs in the Soviet Union, Iraq, and South Africa Koblentz meticulously analyzes what western intelligence knew and what they did not and why. The book includes important tables that basically score intelligence agencies on whether they correctly identified a biological weapons production facility or not. 

The other aspect of this book is a very in-depth critique of the intelligence shortcomings that led to the mistaken conclusions regarding Iraq's post-Desert Storm biological weapons capabilities and intentions. Koblentz approaches this task not with a partisan aim but to better understand the nuances of infamous informer Curveball's revelations in order to improve intelligence capabilities in the future (in 2003 just 6 analysts in the CIA were devoted to biological warfare). His ideas for intelligence improvements are reflected in some of the newly released recommendations for the Blue Ribbon Study Panel on Biodefense. 

For those wanting an intellectually rigorous overview of a fascinating field that provides a foundation for a viable path forward, Living Weapons is a great addition to one's library.

Why Do People Fear Pink Eye so Much?

One of my general frustrations is the inability of many people to be able to accurately weigh the risks of certain conditions. It was strikingly apparent with last year's panic over Ebola and the lackadaisical approach many take to the perennial killer influenza. 

A condition that strikes fear into the hearts of daycare operators and babysitters alike is pink eye. Pink eye is the colloquial term for conjunctivitis, inflammation of the white of a person's eye. It is extremely common, especially if you wear contact lenses. It has various causes some of which are actually contagious (or infectious for that manner).

Viral causes are largely due to adenovirus and can be extremely contagious, but disease is self-limiting and simple hygienic practices such as not sharing towels, face clothes, and frequent hand-washing are advised. No specific treatment other than topical decongestants is required. Bacterial forms, often characterized by the pus-induced matting of eye lashes after sleep, require topical antibiotic therapy. Allergic conjunctivitis is treated with topical anti-histamines and similar medications. 

While I don't dispute that it can be a real issue if a contagious form of conjunctivitis is marauding its way through a day care center, it strikes me as paradoxical when a child with conjunctivitis--a mild benign illness--is exiled from school but those lacking vaccinations against such diseases as measles and chickenpox are welcomed with open arms.

If one were to gauge the severity of an infection only by the degree of fear, preparation, evasive action, and urgency by the general public pink eye, lice, crabs, bed bugs, and scabies would easily outrank measles, influenza, tuberculosis, and everything else.

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.