Expert advice from DrBill100 or someone similar needed.

I am a former heavy drinker. Consumption prior to sobriety was 1.5 - 2.25 L of 14% red wine daily, with occasional increases, for an extended period. At 4 weeks and 10 days into sobriety I was PEth tested and the result came back positive from United States Drug Testing Laboratories at 73 ng/ml with a cut off 20 ng/ml. All other drug testing (blood, hair, and urine) came back negative, including a urine EtG/EtS test. I was discharged from inpatient treatment 5 days prior to testing, with documented sobriety while in treatment. I had some incidental contact with hand sanitizer and mouth wash between discharge and initial testing. From what I understand if this was a problem it should have been reflected in the EtG/EtS test, which it was not. I do understand that incidental contact is not reflected in the PEth assay. Additionally, labs at admission were GGT of 337 and a MCV of 109. How can this positive result be reasonably explained as I am 100 percent certain of sobriety during this period?

I am in a monitoring program and the monitors feel certain this represents relapse.

The explanation I am developing, after some research, is that this must represent PEth that had not yet cleared my body from my initial time of sobriety. Data I have found to support this follows.

Dr Scott H. Stewart from the MUSC College of Medicine gave a presentation, "Testing for the Heavy Use of Alcohol" in which he states PEth levels can persist in heavy drinkers for 4-6 weeks after the cessation of alcohol.

In the International Journal of Molecular Sciences: 2012, 13, 14788-14812 there is an article "PEth Degradation in Human Blood" which states of 57 subjects, 64% had detectable levels of PEth after 4 weeks of sobriety.

Help or literature supporting this position or any assistance with another reasonable explanation would be greatly appreciated .