A circumcision ritual practiced by some Orthodox Jews has alarmed city health officials, who say it may have led to three cases of herpes -- one of them fatal -- in infants. But after months of meetings with Orthodox leaders, city officials have been unable to persuade them to abandon the practice.

The city's intervention has angered many Orthodox leaders, and the issue has left the city struggling to balance its mandate to protect public health with the constitutional guarantee of religious freedom.

"This is a very delicate area, so to speak," said Health Commissioner Thomas R. Frieden.

The practice is known as oral suction, or in Hebrew, metzitzah b'peh: after removing the foreskin of the penis, the practitioner, or mohel, sucks the blood from the wound to clean it.

It became a health issue after a boy in Staten Island and twins in Brooklyn, circumcised by the same mohel in 2003 and 2004, contracted Type-1 herpes. Most adults carry the disease, which causes the common cold sore, but it can be life-threatening for infants. One of the twins died.