Thursday, May 28, 2015

Diagnostic Errors Negatively Impact Antibiotic Use

It is well known that antibiotics are overused. Even when the diagnosis of an infectious disease is correct, the choice or combination of antibiotics is commonly inappropriate.

Here is an interesting article on how diagnostic errors can impact the misuse of anti-infectives.

In the VA Health System, blinded reviewers judged the accuracy of the initial provider diagnosis for the condition that led to an antimicrobial course and whether the course was appropriate.  The diagnoses were correct in 291 cases (58%), incorrect in 156 cases (31%), and of indeterminate accuracy in 22 cases (4%). In the remaining 31 cases (6%), the diagnosis was a sign or symptom rather than a syndrome or disease.

Here is where things become more interesting. Even with a correct diagnosis, 181/292 courses (62%) were appropriate, compared with only 10/208 (5%) when the diagnosis was incorrect or indeterminate or when providers were treating a sign or symptom rather than a syndrome or disease (P<.001).

This is an important point: to impact inappropriate antibiotics use, without a systematic approach to improving clinical-diagnostic reasoning, current efforts will fall short. This is a tall order and I am not optimistic.

Sunday, May 24, 2015

Antibiotic Resistance- From Farm to Family

Here is a TED video featuring Dr. Lance Price.

The video is concise and informative and highlights how the massive use of low dose antibiotics as 'production tools' (to make animals grow faster) rather than as therapeutic agents leads to the emergence of drug resistant pathogens. Darwinian evolution to the core.

With animal overcrowding in feedlots cross transmission is easy. Downstream transmission to humans is the next step.

Antibiotics are societal drugs, the misuse of these agents impacts more than just the immediate users.

The answer is not new antibiotics, the system of antibiotic overuse (both in food animal production and in healthcare settings) must be addressed.

This is the call to action- both daunting and essential for the preservation of antimicrobials.

Saturday, May 16, 2015

Infectivity vs Infectiousness

Source: The Guardian UK
Lately I have been fielding questions about the dangers of infectious diseases. I guess that this is not uncommon for an infectious diseases physician and an epidemiologist. A recent question was about infectivity vs. infectiousness, prompted by concerns about risk.

Infectivity is the ability of a pathogen to establish infection. Infectiousness is the ability of an infection to spread from one person to another, by contact, inhalation or by way of a vector.

So while one may only need one particle of Ebola Virus to cause disease (infectivity), transmission (infectiousness) from person to person is not possible without direct contact of infected bodily secretions. In contrast, it takes more influenza viral particles to cause disease, yet these particles are more easily transmitted via inhalation of aerosoles or droplets. 

The above has nothing to do with severity of disease as this is an entirely different matter. The fatality from Ebola is very high while fatality from influenza is low. Severity results from the host-pathogen interaction and can be mitigated by vaccines and treatments.

However, the burden of disease must also be considered. Given the prevalence of influenza worldwide, even with a fatality of < 1%, the estimated global burden is about 3-5 million cases of severe illness and about 250,000-500,000 deaths per year, as reported by the World Health Organization. This far outpaces the death toll from the recent Ebola outbreak.

The risk of contagion varies by infectivity, infectiousness (transmissibility) and burden of disease.

Thursday, May 14, 2015

VCU Unique Pathogens Unit

VCU President Michael Rao (left) with Governor McAuliffe
It is not often that the VCU Unique Pathogens Unit is visited by the Governor.

Governor Terry McAuliffe (D) of Virginia paid us a visit this week. The NBC news clip can be watched here.

In a 40 minute visit, we covered a lot a ground, including the rapid evolution of our Unique Pathogens Unit, the model on which it is staffed and even some of the particulars of donning and doffing the personal protective equipment.

Wednesday, May 13, 2015

Choosing Wisely- Infection Prevention

Recently the SHEA Guideline Committee was approached by the The American Board of Internal Medicine Foundation Choosing Wisely initiative. The Choosing Wisely initiative aims to provide concise, evidence based recommendations to minimize unnecessary tests, procedures and treatments. The SHEA Guidelines Committee is tasked to define important, evidence based infection prevention action items.

Choosing Wisely recommendations by our colleagues in the Infectious Diseases Society of America include:

These are just a few examples.

We hope to define some important Choosing Wisely comments for infection prevention. Perhaps one to consider should be: Don't examine patients without performing hand hygiene or something of that ilk.

Stay tuned.

Wednesday, May 6, 2015

Claude Bernard- The Unsung Hero of Medical Empiricism

Louis Pasteur is well known in the history of medicine but what about his contemporary Claude Bernard?

I read with great interest this article about physician and scientist Claude Bernard in The Pharos (full text article not available).  A beautiful summary of his life can be found on this tribute and educational website.

Claude Bernard was a failed playwright who stumbled into a career in medicine. His passion for knowledge, philosophy and science led him to a career in experimentation and observation, setting the foundation for empiricism in medicine, the basis of modern medical science and practice. 

Perhaps due to his quiet, intellectual nature and lack of self-promotion, his name is not well known to most medical students and physicians. His contributions, however, are long lasting.

Claude Bernard is an unsung hero in the history of medicine.

Tuesday, May 5, 2015

Animals in Healthcare- Infection Prevention Risk

Along with my esteemed colleagues at the Society for Healthcare Epidemiology of America, we published this expert guidance on animals in healthcare facilities.

Little published data exist on the true risk of animals in the healthcare environment so this guidance statement was a challenge.

In brief, not all animals pose the same risk and dogs are likely the safest pets for entry into the hospital.

VCU has its own Dogs On Call program, as highlighted here in VCU News.