Bloomberg said he would not outlaw the little-known practice in which a rabbi draws blood with his mouth after a circumcision to clean out impurities.
The custom is thousands of years old, but this year health officials investigated Rabbi Yitzchok Fischer of Rockland County after an infant he circumcised that way died from herpes.
At the time, city lawyers called the practice "a threat to the public health," the New York Post said. But, Health Commissioner Thomas Frieden says his department "has no intention of banning or regulating the practice of metzitzah b'peh."
The New York Daily News said, the health department has drawn up an order banning Fischer from performing the rite. The rabbi has until next week to respond.