Health authorities began contact tracing after a man in his 20s tested positive for monkeypox in Victoria, becoming the state’s fourth known case.
The man is isolated after his recent return from Europe.
A small number of people are believed to have had contact with the man. They are contacted by the state health department.
Symptoms of the virus, which has spread internationally in recent weeks, include fever, chills, muscle aches, swollen lymph nodes and exhaustion.
Three other Victorians, including another man in his 40s, had already tested positive after returning from Europe.
The disease is endemic in Central and West Africa and is usually spread by contact with animals or by eating wild game.
Children who are not vaccinated against smallpox are said to be at higher risk of illness and death.
From July 1, monkeypox will become a reportable disease in accordance with Victorian legal requirements.
Anyone with symptoms is urged to seek medical attention immediately.