The Central African Republic has become the latest country in the region to declare an outbreak of the mpox virus.
Infections have spread to the capital, Bangui, after being restricted to rural areas, health minister Pierre Somse said.
He also told a local radio station that some families were hiding infected relatives due to stigma, thus increasing the risk to others.
Cases of the highly infectious disease have recently been detected in Rwanda and Burundi, while a new strain has been spreading in the Democratic Republic of Congo.
On Monday, Dr Somse told reporters the risk of transmission between individuals is now very high because Bangui is relatively densely populated.
Mpox, which used to be called monkeypox, spreads from animals to humans and between people through close contact, contaminated objects and respiratory droplets.
It can cause symptoms such as fever, muscle aches and lesions across the body. If left untreated, mpox can be deadly.
According to medical charity Doctors Without Borders (MSF), DR Congo has recorded more than12,300 suspected cases and 479 deaths in the first half of this year.
Experts say the new strain there has an estimated death rate of 10%.
Neighbouring Burundi recently confirmed three new cases while Rwanda detected two.
South Africa has recorded 20 cases, including two deaths.
Mpox is endemic in parts of west and central Africa and cases have been on the rise on the continent for decades.
In 2022, a worldwide epidemic of mpox affected Europe, Australia, the US and many other countries.
Additional reporting by Richard Kagoe
