Durbridge was one of the 165 riders who returned a negative result under UCI-mandated testing after Stage 9 as part of procedure for the rest day.
But Team BikeExchange-Jayco announced the morning of Stage 10 to Morzine that Durbridge had returned a positive result and was experiencing mild symptoms.
The West Australian joins Geoffrey Bouchard (AG2R Citroen, Guillaume Martin (Cofidis) and Vegard Stake Laengen (UAE Team Emirates) as riders who have been forced out of the race due to the virus.
Team director Matt White called for a review of the UCI testing protocols for riders in the wake of losing Durbridge to the virus, for an event where crowds and media are free from major restrictions but riders are not.
"To lose one of your athletes is a big disappointment for us," White told SBS prior to the start of Stage 10.
"In 2020, we were abiding by the rules of the health departments of countries. We had our own separate dining areas and the testing rules were different.
"Those rules are now gone, but we still get tested and have harsh consequences if we test positive.
"The UCI are the ones that make the rules, but the world has moved on and I think our rules for COVID need to be reviewed. There's some things that can definitely be improved."
White also pointed out that some riders have been allowed to continue in the race despite positive test results, depending on the strength of their infection.
Rafal Majka (UAE Team Emirates) and Stage 9 winner Bob Jungels (AG2R Citroen) are two such riders who previously tested positive with a rapid antigen test, but had little to no symptoms and exhibited low risk of transmission on follow-up PCR tests.
"At the end of the day, Durbo woke up feeling sick this morning and it should be a medical decision," White said.
"And it was a medical decision, he didn't start. But there's been other cases where people have been positive and had no symptoms."
