Should an EtG always be performed to confirm a positive urine alcohol test?
Urine alcohol as an indicator of alcohol consumption can be falsely positive secondary to in-vitro fermentation. Therefore, traditionally, whenever there’s a positive urine alcohol, labs have examined the specimen for glucose and yeast, which can suggest the possibility of fermentation. However, the presence of glucose and yeast doesn’t prove the individual did not drink alcohol. In addition to false positives from fermentation, there’s also been a question of positive urine alcohol tests due to “incidental” alcohol exposure (i.e. mouthwash, food, otc meds, etc). There is no data on this subject. In-vitro fermentation can cause a positive EtG because bacteria can in some situations metabolize alcohol into EtG. This has not been shown with EtS, proving the importance of performing EtS and EtS together whenever possible. Testing all positive urine alcohol samples for EtG and EtS makes sense. Here is a suggested protocol: For a positive urine alcohol, confront the individual regarding the
