Japan's health ministry says a man in his 30s has died from mpox. This is the country's first known death from the viral disease formerly called monkeypox.

The ministry says the man was a resident of Saitama Prefecture, north of Tokyo. It says he was also infected with the HIV virus and immunocompromised.

Mpox is a viral infection that causes symptoms such as fever and rash. Many patients have mild symptoms and recover naturally. But children, pregnant women and people with reduced immunity are said to be at risk of serious illness.

Japan's first case of mpox was confirmed in July last year. The health ministry says 227 cases were confirmed until December 3.

People can be infected with the virus through contact with blood or other body fluids of infected persons or animals, or extended exposure to droplets at a close distance.

The health ministry urges people to take basic anti-infection measures such as sanitizing their hands, and to consult medical institutions if they develop fever, rash or other symptoms.

Professor Morikawa Shigeru of the Okayama University of Science says the mortality rate for mpox patients is said to be less than 1 percent.

But he says cases have been reported overseas in which mpox patients with compromised immune systems due to HIV infection or other illnesses experienced severe symptoms or died.

The professor says those at high risk of becoming seriously ill and suspected to be infected should seek immediate testing and treatment if their health conditions deteriorate.