Staff file photo / Vehicles move down the assembly line in this pre-coronavirus outbreak file photo taken at Volkswagen's Chattanooga production plant.

Volkswagen on Wednesday reported that 31 of its Chattanooga employees and contractors have tested positive for the coronavirus since the automaker resumed production on May 17.

That number of positive cases is up from mid-June when the plant said there were 12 cases among its employees, contractors and suppliers since assembly restarted in May after a two-month shut down.

According to VW, the company has tested 520 employees and contractors since the return of workers two months ago. While 31 came back positive, that's less than 6% of those tested and fewer than 1% of its 3,800-employee workforce, the company reported.

Tom du Plessis, VW Chattanooga's chief executive officer, said on Wednesday that the more than 90 health and safety steps put into place at the plant since reopening are effective.

"From those results, our system and what we're doing is working. It's not cars at all costs," he said, adding that the safety of VW's employees is the primary concern.

Contact tracing has determined that all the positive cases but one were the result of exposure outside the plant, du Plessis said.

"Transmission has taken place outside, not inside," he said. "People need to change their behavior on the outside."

A Facebook post earlier this month from a woman who said her husband worked at the plant had complained about "soaring" cases of the coronavirus and raised questions about procedures, screening of workers and transparency.

The plant CEO said the company has shared coronavirus data with employees "since day one."

"We've been totally transparent with that," he said. "That has been successful for us. We've nothing to hide."

Plant spokeswoman Amanda Plecas said in an email that the company shares an update on coronavirus cases daily. That information includes an aggregate of positive-case individuals who've entered the plant since March, a total of on-site and off-site cases such as with suppliers, and reported negative tests, she said.

Also, the plant shares the specific areas of the plant where there was prolonged exposure to the virus, the number of close contacts identified, the date a person was last in the factory and an overview of health and safety protocols, Plecas said.

"We follow CDC protocols for contact tracing, disinfecting and quarantining," she said.

Plecas said that as soon as someone is suspected of potential exposure to the coronavirus, the employee's badge access to the plant is suspended.

"Those individuals must test negative for COVID-19 in order to return to the factory," she said.

Of the 31 positive cases, 13 employees have completed their quarantine periods, received two negative test results and returned to work, according to VW.

Plant CEO du Plessis said production has been impacted at the plant when people test positive or test results are pending for other workers.

He said that absenteeism hasn't been "abnormally high," putting the number at 1% or a little more.

Production volume at the plant, which assembles the Atlas and Atlas Cross Sport SUVs and the Passat sedan, is back at pre-coronavirus levels, du Plessis said.

"We've really got great demand for our vehicles," he said, particularly the SUVs. "We're very low on stock."

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