John Catanzara made that announcement Sunday on social media.
He has previously stated he is vaccinated against the virus, but it is unclear if he has had a booster shot.
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Catanzara says he has mild symptoms and are already subsiding.
"Came down with COVID Thursday night. Apparently, Friday morning, after testing negative in the morning and testing positive like 20 hours later," he said.
Catanzara is due in court Tuesday for a lawsuit involving the city. He says he hopes to be there.