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. 

Spring Cleaning: An Opportunity to Inhale Rodent Urine

When I travel, I really enjoy reading local newspapers in order to get an idea of the issues that affect an area. Usually, these issues have little to do with infectious diseases but yesterday I came across an article regarding hantavirus in Utah. 

Hantavirus is a potentially lethal disease that came to public awareness after a large outbreak in 1993 in the Four Corners region. It also caused an outbreak at Yosemite in recent years.

Hantavirus is contracted via the inhalation of rodent urine and droppings (it happens more commonly than you might imagine) and it is no surprising that the change in season coincides with cases.  Spring cleaning of sheds and other areas stirs up these substances allowing them to be inhaled. 

The lesson: be careful when spring cleaning. 

While You Were Thinking About Ebola, Lassa Fever Came Over

While most of the media is occupied with speculating about the likelihood of Ebola utilizing a plane to make an appearance in North America--a feat it has been unable to accomplish--Lassa Fever appeared in Minnesota.

The case involves a traveler to West Africa who presented to a Minnesota hospital on March 31, 2004 with fever and confusion. 

Like Ebola, Lassa Fever is a viral hemorrhagic fever but, in contrast, is spread via rodent urine and has had 8 (counting this episode) appearances in the U.S. related to infected travelers. Another difference from Ebola, which may play a role in its ability to appear in disparate locales, is that its incubation period is at least 1 week. Because of this incubation period length, those harboring Lassa Fever have a higher opportunity to travel whereas those with Ebola have a much lower capacity to do this with an incubation period that can be as short as 2 days (note Ebola can have an incubation period of up to 21 days, so this isn't the total answer). 

What is striking about this Lassa case is that it--again--demonstrates the value of the astute clinician who integrated the patient's symptoms with his travel history and made the diagnosis. 

Chance does favor the prepared mind. 

Not Quite A Tricorder, But Getting Closer: Appendicitis in a Few Drops of Blood

A potentially pathbreaking new diagnostic test for appendicitis is being evaluated by the FDA.

Usually, appendicitis is diagnosed by a combination of physical exam findings, ultrasound, and CT scanning coupled to basic laboratory tests.

The status quo, however, leads to many unnecessary and costly tests (particularly CT scans).

Venaxis has developed a simple blood test that measures the blood markers C-reactive protein and calprotectin. The results of these measurements are integrated in a proprietary algorithm with the WBC count to generate a prediction regarding the presence of appendicitis.

Depending on the negative predictive value of the test, it could have a major impact on the diagnosis of appendicitis which often takes hours in busy EDs with no time to spare. Also, such tests which leverage the increasing knowledge of host inflammatory and immune molecules, will become more common in the future transforming the practice of medcine.