The New York City Board of Health voted unanimously in favor the new regulation, citing the risk that infants could catch a potentially deadly herpes infection through the ancient ritual.

The decision to amend the city's health code has angered some members of the city's Orthodox Jewish communities, who say it is an unwarranted intrusion by the government on religious freedom.

But city health officials say at least 11 infant boys contracted herpes between 2004 and 2011 in New York, most likely caused by a mohel, or ritual circumciser, using his mouth to suck away blood following circumcision.

The practice is common only in certain ultra-Orthodox Jewish communities.

Two of the boys died and two others suffered brain damage and that is what prompted the rule change, health officials said.

Under the amendment, the mohel must get a signed consent form from a parent or legal guardian of an infant before performing the circumcision. The form will state that the health department advises parents that "direct oral suction should not be performed" because of the herpes risk.

Mohelim, as the circumcisers are called in Hebrew, who do not comply could receive a warning letter from the department or a fine of up to $2,000. The department said it would not actively monitor mohelim, and would investigate only if a parent complains or if it learned of cases of neonatal herpes that are believed to have followed a circumcision.

Speaking before the board voted, Health Commissioner Thomas Farley said it was "a very difficult issue" but that the department had tried to be as un-intrusive as possible by leaving the ultimate decision about whether to follow the practice with mohelim and parents.

Opponents of the amendment say the department has not proven there is a higher incidence of neonatal herpes among boys who have received oral suction, saying its statistical analysis of the small sample of cases was flawed.

In August, about 200 Orthodox rabbis issued a decree accusing the department of spreading "lies and misinformation."

"We are decreeing that according to our opinion, it is forbidden according to the Torah to participate in the evil plans of the NYC Health Dept. in any form," their statement said, according to a translation published by Yeshiva World News.

(Editing by Tom Brown and Richard Chang)

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