Positive urine alcohol and negative EtG?
We’ve had a few instances of positive urine alcohol (low levels) and negative ETG. We are suspecting perhaps our lab cut off for urine is lower and more specific, than the cut off for ETG. What do you think? Answer: Urine EtG (and even better EtS) is actually more “specific” than urine alcohol since alcohol can be present in urine without drinking (if it ferments there) but the most likely reason to have EtG and particularly EtS in the urine is if alcohol has been present in the body. So there are really only three reasons you can have a positive urine alcohol and negative urine EtG and EtS. 1. The alcohol fermented “in-vitro” in the urine, 2. The urine was obtained very soon after drinking, since it takes EtG longer to appear in urine than alcohol, or 3. The cutoff value for EtG and EtS is too high. In the case of #1 there is evidence that not only can yeast ferment alcohol but also some bacteria and the amount of glucose neccessary can be small. So it’s not just in diabetics with yea
