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.

Polio Re-enters Equatorial Guinea

The eradication of the poliovirus suffered another setback. In the past, I have discussed the number of countries still harboring the virus and the threat that spill over events pose to neighboring nations. 

So in recent weeks, Equatorial Guinea, a country that hasn't had a polio case in over a decade has reported one.

The sequence of the virus isolated indicates it came from Cameroon (where 3 cases have occurred in 2014). The threat of these spillovers is reinforced because the Cameroon cases which began in 2013 were the result of spillover from cases in Chad which were themselves spillovers from Nigeria, where the disease remains. 

So, the current scoreboard is 37 cases--a case count higher versus this time last year--in 5 countries. The Big Three: Afghanistan, Pakistan, and Nigeria remain the heads of the polio hydra that urgently need decapitation.