It comes after Monday saw 36 cases reported, more than doubling the previous amount to 57.
The UKHSA has now told anyone at high risk of having caught monkeypox must self-isolate for three weeks.
The advice applies to anyone who has had “unprotected direct contact or high-risk environmental contact” with a confirmed case.
People are considered to be at high risk of having caught monkeypox if they have had household contact, sexual contact, or have changed an infected person’s bedding without wearing protective equipment.
MORE TO FOLLOW