A new mpox outbreak in Sierra Leone and a rising case toll across Africa are fueling urgent calls for stronger containment efforts, even as the Democratic Republic of Congo (DRC) finally speeds up its mpox vaccine drive and Rwanda’s swift response to Marburg suggests a model for epidemic control.

Health authorities in Sierra Leone have reported the country’s first cases of mpox, with two confirmed infections in the country’s Western Area Urban and Western Area Rural districts. The cases, announced on 10 January, have no known travel history, and 25 contacts are being monitored, according to the Africa Centres for Disease Control and Prevention (Africa CDC).

The outbreak in Sierra Leone adds to the growing burden of mpox across the continent. Dr Jean Kaseya, Director-General of Africa CDC, described the situation as a major public health emergency and urged governments to intensify containment efforts. “We are seeing a sharp increase in cases compared to 2023, and this remains a significant threat to public health in Africa,” Kaseya said in a press briefing on Thursday.

Africa has recorded 77,888 mpox cases over the past year, with 16,767 confirmed infections across 21 countries, according to Africa CDC data. The Central African region continues to bear the brunt of the outbreak, accounting for 85% of all confirmed cases and 99% of deaths, with the DRC serving as the epicenter.

The death toll in 2024 reached 1,321, with a case fatality rate of 1.8%, highlighting the severe impact of the new clades of the virus that have emerged, particularly Clade 1b. “This outbreak is driven by the lack of adequate testing, slow vaccination rollout, and gaps in community-level health interventions,” Kaseya said.

DRC has improved vaccine deployment and is shifting to community-based vaccine strategy – Kaseya  

Kaseya also acknowledged concerns over the sluggish vaccine rollout, confirming that the DRC had received 365,000 doses of the MVA vaccine, but had only administered 55,000 doses, as of early December.  

But he contended that there had been improvements since. “In the past month alone, we have administered over 120,000 additional doses, and we are now moving to a targeted vaccination of entire high-risk areas instead of just contacts,” Kaseya said.

The shift from a contact-based approach to a wider community-based immunization effort makes it much easier to deploy vaccinations more rapidly. 

Additionally, Africa CDC has deployed 80 epidemiologists and 2,400 community health workers to hotspot regions, including DRC, Uganda, and Burundi, in an effort to strengthen surveillance and case management, the Africa CDC director said. 

Africa CDC  has also secured Japan’s LC16 vaccine to be deployed in February and March, primarily for children in DRC, he added. Whereas the milder Clade 2 mpoxvirus, that triggered a WHO global health emergency in 2022-23 was transmitted largely between men having sex with men, children have been amongst the hardest hit  in the outbreak of the Clade 1B virus.

Unlike the Bavarian Nordic MVA-BN vaccine, the LC16 has been approved for administration to children. However, the vaccine requires an ‘intradermal’ (ID) jab, [between the upper and lower skin layers]. The vaccine was commonly used in the early and mid-2oth century to administer the first vaccines against smallpox, typhoid and other diseases, and is still used for the Bacille Calmette-Guérin (BCG) vaccine against tuberculosis. It also offers certain advantages due to smaller dose requirements. However, ID jabs fell out of fashion in recent decades and younger health workers will require training to administer them properly.  

China becomes ninth country outside Africa to report an mpox Clade 1b case

Meanwhile, the outbreak of Mpox Clade 1b has continued to spread abroad. On Jan. 9, Chinese health authorities confirmed a case, linked to a traveler returning from Africa, Kaseya said. That made China the ninth country outside of the continent to report a case of the more deadly mpoxvirus clade, after a case reported by Belgium in December. 

“This is an opportunity for global collaboration,” Kaseya said. “We need solidarity in responding to emerging health threats.”

The deadly Clade 1b triggered a second WHO health mpox emergency declaration in August 2024 – due to the infection’s spread across the continent and its even more deadly potential – even if it had not yet been reported as widely in other regions of the world.    

WHO showcases Rwanda’s successful Marburg response

While the continent continues to grapple with mpox, Rwanda was being commended for its response to the Marburg virus outbreak last year.

Speaking at the launch of WHO’s  2025 Health Emergency Appeal for $1.5 billion, Prof. Claude Muvunyi, Director-General of the Rwanda Biomedical Centre, outlined how the defeated its first Marburg virus disease (MVD) outbreak in September 2024 with a coordinated response. 

“From the very start of this outbreak, the government of Rwanda activated its emergency response mechanism, prioritizing the health and safety of our people,” Muvunyi said. “We rapidly deployed specialized teams for case detection, contact tracing, and patient isolation.”

He noted that one of the significant achievements was the establishment of a specialized Marburg treatment center, which helped reduce the case fatality rate (CFR) to 23%—notably lower than the typical 24-88% CFR seen in previous Marburg outbreaks.

He acknowledged the World Health Organization’s key role in providing technical expertise, laboratory test kits, and personal protective equipment. He added that WHO also facilitated the deployment of 39 health professionals from Uganda, Liberia, and Sierra Leone to strengthen Rwanda’s capacity.

“WHO’s support gave our clinicians confidence in managing the disease, contributing to one of the lowest recorded fatality rates for a Marburg outbreak,” Muvunyi said.

Rwanda’s experience, he added, underscores the importance of early detection, regional collaboration, and sustained global health investments. “We must continue investing in global health security. Outbreaks do not happen in isolation, and without timely interventions and predictable funding, the next emergency could be just around the corner,” he said.

Concerns Over Marburg Virus in Tanzania

But while lauding Rwanda’s success, Africa CDC said it was now closely monitoring a suspected Marburg virus outbreak in Tanzania. The first suspected case, a 27-year-old pregnant woman, died on 16 December, followed by a health worker on 27 December. Thus far, nine suspected cases and eight deaths have been reported, though five samples tested negative for Marburg. The Africa CDC said it is maintaining surveillance in the region.

In a statement issued on Thursday, WHO AFRO said authorities have deployed a team of experts to Kagera region, in Tanzania’s north-west where the suspected cases have been reported. It highlighted the need for early notification of the outcome of the investigation, describing it as crucial in facilitating swift response.

“We stand ready to support the government in its efforts to investigate and ensure that measures are in place for an effective and rapid response,” said Matshidiso Moeti, WHO Regional Director for Africa, who is due to retire soon. “With the existing national capacities built from response to previous health emergencies, we are able to swiftly scale up efforts to protect communities as well as play our advocacy role for international support and solidarity.”

In the new year, As Africa CDC said it is intensifying its response, focusing on expanding laboratory capacity, strengthening testing, and deploying rapid-response teams to contain the spread of mpox.

“From now until March, we are intensifying efforts in hotspots, expanding vaccination, and ensuring that public health systems are resilient enough to manage this outbreak,” Kaseya said.

Image Credits: Africa CDC , BBC/YouTube.