A strain of mpox disease that had previously been undetected in the U.S. has been found in California. The patient contracted it after traveling from East Africa, where there has been an outbreak of the clade I strain. The person was treated in San Mateo County and then released. The person is at home recovering. The CDC says the strain presents a low risk to the general public. 'Casual contact, like you might have during travel, is unlikely to pose significant risks for transmission of mpox,' it said.