Legionnaires disease lessons – 40 years on

Dr. Joseph McDade discovered the bacterium that causes Legionnaires disease. The Philidephia outbreak at the Legionnaires’ convention that gave the disease its name occurred 40 years ago this month. But it wasn’t until five months later, around Christmas, that Joseph McDade, a CDC microbiologist made a fateful discovery in identifying the legionella bacteria. It would be key to solving the mystery, once and for all. He went back to his samples and re-examined some anomalies that he had noticed earlier. This re-examination led to the discovery of the Legionella bacterium which grows inside amoeba and is therefore not easily identified by normal microbiological methods.

McDade himself states: “I was trained as a research microbiologist and not as a public health microbiologist, And the more I learned about epidemiology, the better a laboratory scientist I became. Because it’s not only about doing the right tests and doing them well, it’s knowing what to test and why. And I found that over time, I started asking the broader questions about what do we think is happening, how can we determine what that is, what tests we should perform and why,” said McDade. “If you’re not asking the right questions about it, the information won’t necessarily be useful.”

Maybe we should learn from these 40 year old lessons and recognise there is more than one way to gather and look at data. Several view points provide a better picture. There is room for both rapid antigen testing and culture testing in fighting Legionnaires disease.