New York City Mayor Bill de Blasio's administration is negotiating with a group of ultra-Orthodox Jews over how to regulate an age-old circumcision ritual while still preserving religious freedom.

In this so-called oral suction, the circumciser sucks the blood from the infant's cut. Health officials have linked the rite to 17 cases of herpes in babies since 2000. Two died and two others suffered brain damage.

Rabbi A. Romi Cohn says he's had no infections after performing 35,000 circumcisions. He believes the infected infants may have contracted herpes before the ritual.

Cohn says he takes sterility precautions as strict as those for medical procedures.

Each year, officials estimate more than 3,000 city babies are circumcised using this method.