Preventing the re-emergence of the Ebola virus in Africa by means of community surveillance

By 12 September 2026, there had been 7000 confirmed cases and 3400 deaths. Seven provinces are now affected, some of which are on the borders with Uganda, the Central African Republic and Congo-Brazzaville. This is the country's 17th Ebola outbreak, and one of the most significant ever. On 17 May, the World Health Organization (WHO) declared a public health emergency of international concern (PHEIC).

For Mathieu Bourgarel, a health ecologist at CIRAD, this re-emergence is not an accident. In DRC, local population groups who have had to flee their villages due to insecurity as a result of conflict in the region, have gone deep into previously little-used forest zones. This has created new contact interfaces between wildlife and humans that favour virus transmission from one species to another. This phenomenon is all the more difficult to predict in that the animal reservoir of the Ebola virus remains unknown.

This episode illustrates a broader issue. Most emerging infectious diseases in humans come from the animal world. Such diseases are known as zoonoses, and their early detection is therefore a major public health issue.

Anticipating the disease at source

Before reaching humans, the virus circulates between wild animals via as yet little-known mechanisms. The great apes, chimpanzees and gorillas, are susceptible to it and die in a similar way to humans. An infected animal carcass in forest can therefore be an early warning sign of the presence of the virus in a given zone. It poses a risk for neighbouring populations, since contact with the blood, secretions or tissues of an infected animal, notably via hunting or bushmeat consumption, is enough for the disease to be passed on to humans.

However, such information is difficult to gather. Carcasses quickly disappear in forests, and dead animals are not always reported, despite awareness-raising campaigns. Hunters and foresters, who are in direct contact with the natural environment, play a key role in detecting virus circulation before it contaminates people.

This type of vigilance means decompartmentalising sectors. "If we want to detect diseases early on, the animal health, human health and environment sectors need to work together", Mathieu Bourgarel explains. "If wildlife is involved, the national parks and environment agencies must be part of the surveillance system. We can't rely on the human health sector alone." This is the crux of the One Health approach, which is particularly necessary given that haemorrhagic fever foci often emerge in zones where health systems are fragile because of conflict and a lack of resources, as is the case in eastern DRC.

ALERT: raising awareness through play

To strengthen the surveillance chain, the World Organisation for Animal Health (WOAH), IRD, the Institut Pasteur and CIRAD have worked with the Bioviva firm to produce a card game, "ALERT". The game was designed as part of the EBO-SURSY project, and tested for the first time in Guinea in 2021, with CIRAD teams working with local communities.

The principle of the game is to work around a board to build, together, the epidemic foci early warning and response chain. The aim is to show that the information transmission chain involves a large number of players, including local communities, hunters, veterinarians, health authorities, etc, and also to make communities aware of their role in surveillance, to ensure that information is passed as quickly as possible to the relevant authorities. "If a single link fails to play its role, warnings will not arrive soon enough", Mathieu Bourgarel says.

ZOOSURSY, the successor to EBO-SURSY

The ZOOSURSY project has taken over from EBO-SURSY since 2024, and is working to strengthen zoonosis surveillance systems in 17 West, central, East and southern African countries.

The project is coordinated by WOAH, and associates CIRAD, the Institut Pasteur, IRD, the University of Helsinki, and the Helmholtz Institute for One Health. It focuses on three main levers:

• Strengthening surveillance and diagnosis: improving coordination between animal health, public health and environmental services, and deploying multi-sector teams to gather field data at the wildlife/domestic animals/humans/environment nexus.
• Training grassroots players : building capacity among veterinary services, students and professionals through teaching and training.
• Raising awareness of zoonoses among local communities: leading campaigns tailored to each local context, along the lines of the travelling cinema being used in Mozambique.