Kenya and the Central African Republic have declared new outbreaks of mpox as Africa’s health officials race to contain the spread of the disease in a region lacking vaccines.

Nairobi announced the outbreak on Wednesday, after a case was detected in a passenger traveling from Uganda to Rwanda at a border crossing in southern Kenya. The Central African Republic was the first to declare a new outbreak on Monday, saying it extends to its capital of Bangui.

Mpox, previously known as monkeypox, is caused by a virus that originates in wild animals and occasionally jumps to people, who can spread it to others.

“We are very concerned about the cases of monkeypox, which is ravaging region 7 of the country,” the Central African Republic’s public health minister, Pierre Somsé, said Monday.

Mpox became a focus of worldwide concern during an international outbreak in 2022 that saw the disease spread to over 100 countries, and has been endemic in parts of central and west Africa for decades.

The World Health Organization said in November it had confirmed sexual transmission of mpox in Congo for the first time. African scientists warned this could make the disease difficult to contain.

Although the mpox epidemics in the West were contained with the help of vaccines and treatments, barely any have been available in parts of Africa where several countries have reported outbreaks in recent months.

The worst hit on the continent is Congo, which has recorded more than 12,000 cases and at least 470 deaths this year in its biggest outbreak. South Africa, which last recorded an mpox case in 2022, has also reported an outbreak this year.

In the Central African Republic, where the infection is most common in remote areas, authorities called for public support to assist efforts being taken by the government to slow the spread of the disease.

The East African Community regional bloc has also issued a statement alerting member states about the disease in Congo, which borders five countries in the region. One of them, Burundi, has already confirmed three cases.

Andrea Aguer Ariik Malueth, the bloc’s deputy secretary general, on Monday urged the group’s partner states to “provide necessary information about the disease and take preventive measures.”