The global outbreak of monkeypox should not be expected to stay confined to specific groups, a World Health Organization (WHO) official said Monday. 

Though cases of the virus have been predominantly reported among men who have sex with men, diseases commonly begin in one community before spreading to others.

“This really might be the canary in the mine that’s alerting to us of a new disease threat that could spread to other groups,” Catherine Smallwood, senior emergency officer at the WHO, said Monday on CNBC’s “Street Signs Europe.”

“At the moment, cases continually continue to be reported among men who have sex with men, for the most part, but we should not expect that to remain as such,” Smallwood added.

Two U.S. children, a toddler and an infant, were diagnosed with monkeypox Saturday, cases that break from the usual demographic.

The WHO declared monkeypox a global health emergency Saturday, and White House COVID-19 response coordinator Ashish Jha said Sunday that the Department of Health and Human Services could also declare the virus a public health emergency in the U.S.

The Centers for Disease Control and Prevention reported 2,891 cases in the U.S. as of July 22 and more than 16,836 cases globally.

The White House has pledged to distribute nearly 300,000 monkeypox vaccines nationwide in the coming weeks and a combined 1.6 million monkeypox vaccines in the coming months.