The Democratic Republic of the Congo (DRC) has declared an official end to its 11th Ebola outbreak nearly six months after it began, marking the first time in years the vast central African country has been free of the deadly haemorrhagic fever.

Eteni Longondo, the DRC’s minister of health, and the World Health Organization (WHO) made the announcement on 18 November after no new cases of the viral disease had been recorded in the country’s western Équateur province for 42 days, or the time of two maximum incubation periods for Ebola. In this outbreak, there were 55 deaths and 75 people who had recovered out of 119 confirmed and 11 probable cases.

The outbreak, which was announced on 1 June, surfaced shortly before the DRC called an end to a separate Ebola epidemic – hundreds of miles away in the east of the country – that killed 2280 people over nearly two years. Genetic sequencing showed that the two virus strains were unrelated.

The latest outbreak stretched vast distances across dense rainforests and remote waterways as well as busy urban areas. It was halted thanks to “cold chain” vaccine storage technology and community-based health workers who vaccinated 40,000 people deemed at high risk of contracting the disease, according to experts.

“The geography was very difficult in terms of accessibility,” says Ngoy Nsenga at the WHO. “It required serious logistics, and so this ultracold-chain technology was very important.”

Known as the Arktek and originally developed by the Global Good Fund, a US-based social enterprise, the cylinder-shaped “super thermos” devices can store 500 vaccine doses at -80°C for up to a week with no external power source. This meets the cold temperature requirements of the Merck Ebola vaccine, as well as those of Pfizer and BioNTech’s new covid-19 vaccine, which bodes well for vaccination in lower-income countries with less-developed infrastructure.

“But there were so many factors in the management of the outbreak,” says Nsenga. “The DRC is gaining experience in stopping epidemics and the WHO has learned to react as quickly as we can.”

Bob Ghosn at the International Federation of Red Cross and Red Crescent Societies (IFRC) says working with local people was crucial to the success.

“Community engagement is key to stopping any outbreak,” says Ghosn, who helped deploy a team of 1000 IFRC community workers in Équateur. “We’ve got much better at it. Top-down messaging doesn’t work on its own – covid-19 has proved that.”

However, experts warn that the risk remains of another Ebola outbreak in the DRC – adding to the 11 since 1976. The disease, which can cause uncontrollable internal bleeding, is zoonotic and is believed to derive from a species of bat.

Natalie Roberts at Doctors Without Borders in France says future efforts are likely to improve with the use of monoclonal antibodies – laboratory-made molecules that can enhance the immune system.

“Due to the remote nature of this outbreak and other constraints, we weren’t able to use them as much as we wanted,” she says. “But they are very effective in the early stages of the disease.”

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A new outbreak of the deadly Ebola virus disease has emerged in the Democratic Republic of the Congo (DRC), more than 1200 kilometres to the west of an earlier outbreak that has been spreading in the country since 2018. It is the 11^th such incident in the DRC since the virus was first discovered in 1976.

As of 14 June, authorities have reported 14 confirmed infections and three probable cases of the haemorrhagic fever in and around the northwestern city of Mbandaka in Équateur province, resulting in 11 deaths to date.

The news comes less than two years after an outbreak of the disease ended in , and while the country’s 10th outbreak is ongoing across the eastern North Kivu and Ituri provinces, which has killed . At the same time, the DRC is contending with the world’s largest measles outbreak and the spread of the coronavirus.

“The last outbreak in Équateur was quickly contained – in less than 3 months – and we will make all our efforts to ensure it is done again,” says Mary Stephen at the World Health Organization (WHO)’s Regional Office for Africa.

Stephen says that expertise and infrastructure built over the years will be invaluable in curbing the new outbreak, and that a programme of vaccinations, door-to-door education and mobile handwashing stations is already underway.

More than 2100 people, including 679 contacts, 1309 contacts of contacts, and 127 likely contacts, have been vaccinated so far, she says. Screenings for more than 100,000 people have taken place at control points between cities, she says.

The WHO has more than 20 staff on the ground supporting the Ministry of Health in Mbandaka, a major port city that sits on the Congo river, close to the border with the neighbouring Republic of the Congo.

“We have a lot of experience in tackling these outbreaks,” says Eteni Longondo, the DRC’s health minister. “But that does not mean we are taking this disease any less seriously. It requires a complex system of epidemiologists, surveillance, infection prevention, risk assessment and contact tracing.”

Longondo says health workers are being given refresher courses before being deployed into Équateur and that personal protective equipment from previous outbreaks is already in place for use.

The United Nations has from its Central Emergency Response Fund to help tackle the new outbreak of Ebola and other health crises in the DRC.

Genetic sequencing of the virus by the DRC’s  has shown that the country’s 11th Ebola outbreak, which was officially declared earlier this month, is likely to have started as a “spillover event”, a transmission from an infected animal.

“The evidence is sufficient to believe with confidence it is a spillover,” says Catherine Pratt at the University of Nebraska Medical Center in Omaha, who was involved in the analysis.

Virus samples from related outbreaks should only have a relatively small number of mutations, as the virus won’t have had much chance to evolve. “This new Mdabanka strain is 350 mutations from the North Kivu strain,” says Pratt. “Therefore, we can say with confidence it comes from a separate source.”

Pratt says bats were probably the source of the outbreak, but that it could have been transmitted to humans through people eating mammals infected with the virus, such as bonobos, which are sometimes consumed as bushmeat.

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“There is no need for a highly equipped lab. This simple test can be done anywhere”

Fresh cases of Ebola have been detected just days before the deadly epidemic in the eastern Democratic Republic of the Congo (DRC) was to be declared over.

The Ministry of Health on Friday confirmed the death from Ebola of a 26-year-old man in the city of Beni in North Kivu province. An 11-month-old girl treated at the same health centre also died, it was announced on Sunday, and a 7-year-old girl is currently being treated for the virus.

It marks a significant blow for the Central African country, which had previously recorded its last Ebola case on 17 February and was on the verge of ending an outbreak that has killed more than 2200 people since August 2018.

The World Health Organization (WHO) said that even before the announcement it was prepared for further cases to emerge. “While not welcome news, this is an event we anticipated,” said Tedros Adhanom Ghebreyesus, the WHO’s director general, . “We kept response teams in Beni and other high-risk areas for precisely this reason.”

High alert

As part of the Ebola surveillance system, health teams on the ground are investigating alerts every day. These can either be reports of those with Ebola symptoms or of deaths in areas that are considered high risk. The WHO said 2600 alerts are currently being analysed across the country’s eastern provinces.

Health authorities had already planned to remain on high alert for the next 80 days, and to provide care for Ebola survivors as part of an 18-month programme of regular check-ups.

Efforts are now under way to find all potential contacts of the new cases in order to offer them vaccination and to monitor their health. If no new cases emerge, the DRC will have to wait another 42 days – the equivalent of two incubation periods for the virus – until the Ebola epidemic can be declared over.

The setback underlines the huge challenge posed in eradicating a virus. The problem is made worse by the arrival of the coronavirus in the DRC last month.

Triple emergency

, Kate Moger at humanitarian organisation the International Rescue Committee called the situation a “triple emergency”. “Vulnerable populations facing ongoing humanitarian crises, the spread of COVID-19, and now again potentially a re-emerging Ebola crisis,” she said.

Flare-ups had been expected in the DRC, which has had 10 outbreaks of the virus since it was first detected in humans near the Ebola river in 1976. The Ebola virus can remain active on medical equipment for weeks and can be transmitted through semen for more than 550 days after a victim has recovered. In rare cases, survivors can also relapse.

A 2019 study warned that the to say with confidence that the epidemic is over because the complex security situation means some cases in the DRC may have gone undetected.

However, officials are confident that the new cases don’t necessarily mean the virus will spiral out of control again, particularly because more than 300,000 Congolese have already been vaccinated.