The city Health Department has reported a new case of neonatal herpes caused by a controversial ritual Jewish circumcision.

The ancient practice — known as metzitzah b’peh — requires a mohel, the person performing the circumcision, to suck blood from the incision on an infant’s penis.

It has long been linked to neonatal herpes and has consistently raised red flags in the medical community.

The practice continues without restriction in the city after Mayor de Blasio made a pledge to the ­Hasidic community during his 2013 campaign to lift a requirement of written parental consent.

Health officials sent out an alert to doctors Wednesday about the latest case and urged them to be vigilant.

The infant in the new case was hospitalized for 14 days and was reported to be ­recovering.

According to the Health Department, 24 cases of herpes have been linked to circumcision since 2000. Two of the infants died and two others suffered brain damage.

Last year, there were two cases. In 2015, there were three cases.

Since 2006, 22 percent of all male neonatal herpes cases were linked to ritual circumcision.

Leaders of the ultra-Orthodox Jewish community have opposed any restrictions on the centuries-old ritual as an infringement on religious freedom.

Mohels who perform the circumcisions are not even required to be tested for herpes, according to Health Department rules.

In a bid to restrict the risky procedure, the Bloomberg administration required parents to sign a consent form.

But de Blasio and the city Board of Health scrapped the requirement in 2015.

As part of a compromise, the Health Department distributes pamphlets to doctors, hospitals and parents warning that “some babies can get herpes, which can even lead to death” following metzitzah b’peh.

Health officials fretted that many parents haven’t seen the brochures.

“Despite these efforts, parents of case-patients infected have not reported seeing the pamphlet or poster,” the department alert to doctors said.

De Blasio said Wednesday the city was “now in the process of identifying the mohel and we expect full cooperation from the community.”