The Massachusetts agency said the virus does not spread easily between people, but transmission can occur through contact with body fluids, monkey pox sores, items such as bedding or clothing that have been contaminated with fluids or sores, or through respiratory droplets following prolonged face-to-face contact.
It said no monkey pox cases had previously been identified in the US this year. Texas and Maryland each reported a case in 2021 in people with recent travel to Nigeria.
The CDC did not immediately respond to a request for comment.
A handful of cases of monkey pox have recently been reported or are suspected in the United Kingdom, Portugal and Spain.
Earlier on Wednesday, Portuguese authorities said they had identified five cases of the infection and Spain's health services said they were testing 23 potential cases after Britain put Europe on alert for the virus.
European Health authorities are monitoring any outbreak of the disease since Britain reported its first case on May 7 and has found six more in the country since then.