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.

Ebola: Playing the Same Tricks

As the Ebola outbreak in Guinea continues, it is following the pattern of prior Ebola outbreaks. 

Several points that I have highlighted in 2 recent media appearances (Boston Globe and BBC--37:10) are important:

• Ebola does not take a tremendous amount of technology to stop it in its tracks--simple hygiene when interacting with the body fluids of Ebola patients or their bodies after death is sufficient 
• Ebola does not spread well--to wit, the cases in Guinea's capital, Liberia and possibly Sierra Leone all appear linked to travelers to and from the original outbreak site in the Guinean forest
• Those infected with Ebola can travel before sickness and may present with illness at a site disparate to the outbreak, but sustained spread in those settings in which even rudimentary infection control can be practiced is not something to be expected
• Closing borders, though a natural response to disease, will not make much of a difference in the spread of this disease

Like the outbreaks--some of which were much larger--before it, I anticipate that the Guinean Ebola outbreak will be extinguished once simple measures are put in place. 

Hospital-acquired Infections: Worse than Wrong Site Surgery

A recent NEJM article, authored by the CDC, estimates that 1 in 25 (4%) of patients contracts an infection as a result of hospitalization. While hospital-acquired infections grab headlines from time to time, the general public and the media tend to give them less attention than say, wrong site surgery. 

I find this paradoxical because I would rather have the wrong knee scoped than contract Acinetobacter pneumonia or Clostridium difficile. 

Insurers increasingly realize that these infections, which are largely the result of inadequate hand hygiene; unnecessary urinary and central venous catheter insertion; and poor antimicrobial stewardship, are not something for which they should pay. 

Just as someone wouldn't pay for a spotty repair job on one's automobile, insurers shouldn't pay for someone who enters the hospital for, say, a hip replacement and leaves with C.diff, MRSA pneumonia, and a catheter-related UTI. 

Emerging from the Forest: Ebola in Guinea

Periodically, for unclear reasons, Ebola appears in Africa, sparks a small outbreak, and then disappears. 

Such is the now the case now with the relatively large outbreak in a forested region of Guinea. Thus far, 59 people are confirmed dead with a total of 80 infected. 

While Ebola captures headlines, two facets of its nature delimit its potential for large, sustained outbreaks:

• Ebola outbreaks tend to end when simple infection control is instituted (barrier nursing)
• Ebola victims are too sick to spread the infection to people other than those in close contact (often those caring for the patient)

What is endlessly fascinating about Ebola is understanding its ecology. I often think of questions such as:

What are the mechanics and logistics of how Ebola spills from bats to non-human primates, antelopes, and humans?

What is the means by which the initial human infection occurs? 

What would happen if Ebola went head-to-head with 21st Century critical care medicine? 

Such questions will likely remain unanswered for some time, but thinking about potential answers is intellectually challenging and may provide great insight into the interactions between humans, wildlife, and pathogens. But each new outbreak brings us closer to the answer.