We “all the sudden have these outbreaks” because monkeypox now affecting young adults rather than just small African children. Gay guy picks it up in Africa, goes back to UK or Canada or wherever, and infects his er, sexual contacts. Who may in turn infect theirs.
“The number of cases has increased at a minimum of 10-fold and median age at presentation has evolved from young children (4 years old) in the 1970s to young adults (21 years old) in 2010–2019. This may be related to the cessation of smallpox vaccinations, which provided some cross-protection against monkeypox. The case fatality rate for the Central African clade was 10.6% versus 3.6% for the West African clade.”