Four recent cases of neonatal herpes infection following a Jewish circumcision ritual have health officials once again urging parents in New York City’s ultra-Orthodox population to avoid the practice or at least limit its risks.

Health officials on Sunday said there have been three cases of herpes simplex virus 1 infections in infant boys reported to the New York City Department of Health and Mental Hygiene since Dec. 1, 2019. The fourth case was reported in September 2019.

Health officials don’t believe the cases are linked. The infants were hospitalized, received intravenous antiviral drugs and are now recovering, health officials said.

Rabbi David Zwiebel, executive vice president of Agudath Israel of America, declined to comment.

The ritual is known as metzitzah b’peh. A mohel, a religious leader who performs the circumcision during a bris, uses his mouth to suck blood from the cut.