In March 2016, we sampled tap water from 5 homes and 6 small businesses in Flint, with ALL testing culture-negative for Legionella. We used a standard culture-method often used by hospitals to determine if there is a risk of Legionnaire’s Disease outbreak. This is good news. We will be following up with another sampling this summer when the weather is warmer and there is more of a tendency of Legionella bacteria to grow.
We are also examining the water samples we have collected more closely using DNA-based methods. The DNA methods may help us detect lower levels of Legionella that we couldn’t see with culture and also identify different kinds of Legionella, but the trade-off is that we will not be able to tell the difference between live and dead bacteria. That is why the culture method is considered the standard for determining risk of getting Legionnaires’ Disease from tap water.
Using the best available science, the sampling we performed in March 2016 showed that if any living Legionella were present, their levels were low the day of testing. There is always some risk of Legionnaire’s Disease from tap water, but our current results from March suggest the risk was not concerning at any of our sample sites in Flint. We will remain vigilant in our tracking and testing of this potential problem in Flint homes.
Only 11 samples for a community @100,000 residents?
Additional questions are elicited:
1-why residences and small businesses? it is logical that these are of lowest risk.
2-hot AND cold water samples, or just “tap-water”? Remember that temperature is needed for amplification (growth) just as you have indicated planned sampling at a latter date, all sampling should take into account potential heat sources.
3-were these sites previously sampled AND positive by the same analytical methods? Negative results for follow-up sampling would indicate true progress.
4-let’s not overlook VBNC (Viable But Not Culturable). It is good that you are taking a closer look here and NOT relying upon only the “gold-standard” for a realistic evaluation.
One final caution. In that the systems being evaluated are complex and dynamic, consideration must be applied w/ the understanding of the establishment of “secondary reservoirs” and even potentially “tertiary reservoirs. All risk evolves from the relationship of these systems acting as Reservoirs, Amplifiers, and Disseminators both individually as well as jointly.
I got legionairres in 2012. I had a water leak n
Beforehand but never heard of this. Eventually i collapsed and was in coma. I wish i hadnt been ignorant to situation. I suffer now 4yrs later and have pneumonia as of late. The aftermath is horrendous. Theres a bill in front of congress due next yr that would allow long term meds for people like me. I hear they want to throw it out. Any help would save lives