Publisher Health

Health officials said on Thursday that a child had been infected with monkeypox in New York City, the city’s first known pediatric case.

In the more than three months that monkeypox has been spreading in New York City, the virus has been diagnosed in nearly 3,000 adults, almost all men. The child is a “household contact” of an adult who had also been infected with monkeypox, the officials at the city health department said. They declined to provide more details.

“There is a juvenile case of MPV (or monkeypox) in New York City,” the city’s health commissioner, Dr. Ashwin Vasan, said in a written statement. “While we understand the concerns of families, we also know that the overall risk of exposure for children in the city remains very low.”

In the present outbreak, monkeypox has been spreading mainly through sexual contact between men who have sex with men, epidemiologists say.

The virus spreads through direct contact with the rash or scab of someone sickened by the virus, but can also spread through respiratory droplets and through contact with objects such as bedsheets or clothing used by someone with monkeypox.

There have been more than 2,888 cases of monkeypox in New York City, with about 50 new cases now turning up each day. Cases in New York City have been decreasing in recent weeks, partly a result of a vaccine campaign that has delivered nearly 70,000 vaccine doses to sexually active gay and bisexual men, as well as transgender and nonbinary individuals.

Doctors and public health experts said that it was possible for children to spread the virus in settings such as school or day care, but that for now children were more likely to pick up monkeypox through an infected family member. The virus is also not as contagious as the coronavirus, for instance.

As of Aug. 21, there were 13 cases of monkeypox in children 10 years old and younger and another four cases in 11- to 15-year-olds nationwide, according to the Centers for Disease Control and Prevention.

The pediatric case in New York was disclosed on the city’s website on Thursday.

The pediatric case came as federal officials projected a sense of optimism about the arc of the outbreak, with Dr. Rochelle P. Walensky, the C.D.C. director, saying that the world “may be turning a corner” in the spread of the disease. The World Health Organization said on Thursday that monkeypox cases globally dropped 21 percent last week.

“I want to be cautiously optimistic,” Dr. Walensky said at a White House news conference, citing “downward trends” in cases in New York, San Francisco and Chicago. “Week over week, our numbers are still increasing. The rate of rise is lower. But we are still seeing increases. And we are of course a very diverse country, and things are not even across the country.”

Dr. Walensky also pointed to revelations in research published on Friday by the C.D.C., which showed that men who have sex with men have changed their sexual behavior because of monkeypox. A survey of gay, bisexual and other men who have sex with men revealed that roughly half said they had cut down on the number of sexual partners and one-off sexual encounters.

“It speaks to the resilience and commitment of this community,” said Dr. Demetre Daskalakis, the White House’s deputy monkeypox coordinator. “The advice about how to reduce risk for monkeypox exposure is for now, not forever, and as an important part of our public health and community response as we urgently surge vaccinations.”

Officials acknowledged that there were still concerning patterns in how monkeypox vaccines were being administered around the country. Some health departments, including New York City’s, have reported racial disparities in who is receiving vaccine doses.

Dr. Walensky said that other data her agency published on Friday showed that many Americans who had received a first dose of the Jynneos vaccine, the main vaccine the government is using for monkeypox, had not been recorded as getting a second. As of Tuesday, she said, nearly 97 percent of the over 207,000 doses administered in 19 jurisdictions were first doses.

“This is a two-dose vaccine,” she said. “And it’s important to receive the second dose.”

Some cities had been holding back second doses because they had too few doses to go around, largely because the federal government had mismanaged aspects of the initial response to the outbreak. The federal government has eased the supply problems by recently switching to a different injection method, known as intradermal injection, that uses only one-fifth of the original dose.

Over a million vials of the vaccine had been offered to states as of Monday, according to Robert Fenton, the White House’s lead monkeypox coordinator.

“We’re approaching having enough vaccine for everyone in the at-risk community to receive two doses of vaccine,” Mr. Fenton said.

Three-quarters of jurisdictions have moved to the new intradermal injection strategy, with another 20 percent “working to move in that direction,” he added.

Asked about reports that some health departments were struggling to extract five doses out of vials, officials said that they were working with states to resolve the matter. Mr. Fenton said that some places were getting at least four and a half doses out of each vial.

States could also order more vaccine if they had gone through 85 percent of their supply, said Dawn O’Connell, the assistant secretary for preparedness and response at the Department of Health and Human Services, adding, “We are not in the business of holding vaccines back.”