Victorian health authorities say there has been a jump in the number of monkeypox cases in the state over the past week.
Victoria now has 59 confirmed cases of the disease — an increase of 20 cases in a week.
The state's health department said most of the new infections spread through people in Melbourne.
Deputy Chief Health Officer Deborah Friedman said case numbers would continue to rise quickly until large stocks of monkeypox vaccine were delivered.
"We're seeing multiple cases a day now whereas previously we were seeing maybe one or two cases a week, so we've seen a substantial increase and I think it's going to continue to increase," she said.
Dr Friedman said health authorities were concerned about the number of infections that could not be traced.
"All of the transmission still appears to be very close and intimate contact so that's definitely still the case, but not all cases identify as gay and bisexual men," she said.
Victoria's Health Minister Mary-Anne Thomas said the state currently had a limited supply of vaccine doses for the virus.
"We're working hard with the Commonwealth to make sure we get vaccines rolled out here as soon as possible and we're expecting more vaccines to come in September," she said.
The minister said around 20,000 vaccine doses were expected to be delivered in September.
The health department said the current outbreak was still disproportionately affecting men who had sex with men, but the virus could affect anyone who had prolonged close contact with another person who had the disease.
Symptoms of monkeypox can include a rash, fever, chills, muscle aches, backache, swollen lymph nodes, and exhaustion.
