Monkeypox has now spread across 23 of Nigeria’s 36 states, the country’s health authorities say.
The outbreak, which began in September, has infected 61 people and one person has died.
But the Nigeria Centre for Disease Control said the number of new cases was now declining.
An awareness campaign – including warning people against eating monkeys and bushmeat – and surveillance measures were in place, it said.
Monkeypox is a rare smallpox-like disease, which is not usually fatal to humans.
The virus is transmitted to humans by monkeys, rats and other wild animals, and causes blisters, aches and fever.
Humans can also spread it among themselves.