“Perfect is the enemy of good (microbiology)”

This quote attributed to Voltaire (“Le mieux est l’ennemi du bien”), rings true to me. I have never been a perfectionist, and the idealistic pursuit of perfectionism can hinder real-life achievement and progress. 

The quote came back into my conciousness during the early days of the COVID pandemic when I listened to a great speech by Dr Mike Ryan from the WHO when urging countries to act quickly in the face of the rapidly developing COVID situation.

Of course, such a concept can also apply to the microbiology laboratory.. Here are a few examples:

Protracted work-up of samples: When a sample arrives into the microbiology laboratory, the clock is ticking. In relentless pursuit of isolating that fastidious bacterium, time passes by and before you know it a week has passed… The clinical usefulness of a microbiological result is inversely proportional to the time spent to produce it. In the hospital setting, the average length of stay is 3-4 days… Excessive time spent on certain samples is not only a waste of resources, it also generally does nothing for the patient. Get a result out, even if it is not the perfect one that you are striving for.

Excessive work-up of samples: The classic example of this is identifying every bacterial isolate in a mixture of enteric flora. For the most part, such an exercise is futile, even when isolated from a sterile site. Enteric flora isolated from sterile sites usually represent a source control issue, and who knows what the pathogen might be in the mixture, if any. Such practice is generally a waste of resources, and reporting individual isolates along with individual susceptibilities is time-consuming and often leads to poor antimicrobial stewardship. Working up bacteria within a mixture of enteric flora might be “technically perfect” but does little to help the patient.

Excessive testing protocols: A good example of this is stool samples arriving into the microbiology laboratory. There are many microbiological tests that one can do with a stool sample, culture, PCR for bacterial & viral pathogens, microscopy for parasites, C. difficile testing, the list goes on. However, to perform all the available tests on every stool sample in the hope of maximising the odds of isolating a pathogen would be incredibly expensive, but in most cases would do little to change patient management. Enteric testing should very much be tailored depending on what is on the microbiology request form.

I am sure there are many other examples that one could think of. Perfection in the microbiology laboratory is very much a pipe dream, and can actually be detrimental to good patient care. We cannot possibly hope to identify all potential pathogens in every sample and do it in a timeframe that is beneficial to the patient. We need to move past our fear of missing something…

When developing testing methodologies or reviewing individual patient samples, we should always be asking ourselves “By doing what we are doing, are we providing overall value to the patient?” 




2 thoughts on ““Perfect is the enemy of good (microbiology)”

  1. All so true as ever! Assessors seem to take a different view. And we train people to not miss things. I still remember being marked down in an EQA sample for not picking up Yersinia in a faec. My view was that anyone who did pick up Yersinia should have been marked down for over processing when clinical details not sufficient!

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