Following the resurgence of Ebola virus disease cases in the Democratic Republic of Congo (DRC) and Uganda, the rare Bundibugyo strain is at the heart of public health concerns. Origin of the virus, modes of transmission, symptoms, and prevention measures: discover the complete overview of this disease and the challenges it poses to global health.

International health emergency: understanding the Bundibugyo strain

Following the information provided by the Democratic Republic of Congo (DRC) and the Uganda World Health Organization (WHO) stated that the epidemic of Ebola virus disease linked to Bundibugyo strain constitutes a public health emergency of international concern (PHEIC)According to the criteria of the International Health Regulations (IHR), this situation does not constitute a pandemic emergency.

On May 19, 2026, the WHO Director-General reported 30 confirmed cases in Ituri province in the DRC, 2 confirmed cases in Uganda, 1 death among two people traveling from the DRC, and 1 US citizen who tested positive and was transferred to Germany. More than 500 cases and 130 deaths are suspected.

Ebola virus disease was first identified in 1976 during two simultaneous outbreaks in Nzara, South Sudan, and Yambuku, Democratic Republic of Congo, near the Ebola River, which gave the virus its name. Three main strains are responsible for the major known epidemics: the strains Zaire, Sudan et bundibugyo.

Natural reservoir and transmission: how does the virus spread?

The Ebola virus is believed to be naturally hosted by fruit batsIt can also infect several animal species, including monkeys such as... chimpanzees and the gorillasbut also forest antelopes and even porcupines. The transmission to human beings most often occurs through close contact with infected animals, through exposure to their bodily fluids (blood, urine, feces) or their organs, for example through the consumption of bushmeat contaminated.

La human-to-human transmission It exists through direct contact with the bodily fluids of a person who is ill or has died from this disease, but also indirectly via contaminated objects or surfaces. Infected people become contagious from the onset of symptoms and remain so as long as the virus is present in their body. This is why a person who has died from Ebola can remain contagious for several days after their death, which explains the risk of transmission during the funeral ceremoniesConversely, a recovered person no longer transmits the virus in most cases. However, there is an exception, as it can persist in the sperm for several months after recovery.

What are the symptoms of Ebola virus disease?

The first symptoms Ebola virus disease usually appears suddenly between 2 to 21 days after infection :

The disease can then progress to vomiting, diarrhea, abdominal pain, liver and kidney damage, or even bleeding in the most serious forms. neurological disorders Confusion, irritability, and aggression may also appear, indicating damage to the central nervous system.

Diagnosis and management: the specifics of the Bundibugyo strain

Although rare, Ebola virus disease remains a serious infection in humansIt is often fatal and difficult to diagnose due to initial symptoms that are nonspecific and similar to those of other infectious diseases (such as the flu). biological diagnosis relies on laboratory analyses carried out under high security conditions, as the samples present an extremely high risk of infection.

La Bundibugyo strain remains relatively rare and still poorly documented. Unlike the Zaire strain, No vaccine or specific treatment is currently approved for the Bundibugyo strain.Therefore, care is based solely on... intensive supportive care (rehydration, correction of electrolyte imbalances, management of organ failures).

Ebola virus disease is often observed in areas where access to care may be limited by situations of instability and humanitarian crisis, but also in urban environments where population density and movement can promote the spread of the virus and complicate the control of the epidemic.

Prevention, vaccination and risks of global spread

Prevention measures are based primarily on the rapid case detection and their care. The healthcare staff are particularly exposed and must absolutely use appropriate protective equipment.

More generally, the basic hygiene measures remain essential to limit the risks of transmission:

In certain situations, the vaccination can also be used as a prevention and control tool. Two vaccines are available and validated against the Zaire strain, while others vaccine candidates against the Bundibugyo and Sudan strains are currently under development.

According to the WHO, the risk of the Ebola virus spreading is considered "raised" in Central AfricaMore "weak" on a global scaleIn France, the risk of importing the virus remains very low, although enhanced surveillance is in place, particularly in Mayotte, due to its geographical location.

The "One Health" approach to epidemic risks

In this context, vigilance and coordination of health systems remain essential to limit the spread of the virus. In France, institutions such as thePasteur Institute of Lille actively contribute to surveillance, research and expertise on emerging infectious diseases such as Ebola virus disease.

This joint action incorporates the dimensions of the human, animal and environmental health to prevent epidemic outbreaks. This comprehensive approach is fully in line with the approach "One Health" (One health), which has now become essential at all levels to better protect populations.

Article written by the Dr. Doriane Henry, in charge of scientific communication at thePasteur Institute of Lille (IPL).

FAQ

Ebola virus disease is a rare but serious, often fatal infection, first identified in 1976. It is caused by the Ebola virus, which belongs to the Ebola family. filoviridaeSix species of the Ebola virus have been identified to date, including three main ones responsible for the major known epidemics: the Zaire, Sudan and Bundibugyo strains. 

Ebola virus transmission occurs through close contact with the bodily fluids (blood, urine, feces, vomit) of infected animals (monkeys, antelopes, porcupines), particularly during the handling or consumption of bushmeat. Human-to-human transmission occurs through direct contact with the bodily fluids of infected individuals, whether living or deceased, or through contact with contaminated objects or surfaces. 

Initially, symptoms appear suddenly, including fever, intense fatigue, muscle aches, headache, and sore throat. These can then progress to vomiting, diarrhea, abdominal pain, liver and kidney damage, and, in the most severe cases, internal and external bleeding. Neurological disorders such as confusion, irritability, or aggression may also occur. 

Two vaccines are used for prevention, but only against the Zaire strain. Other vaccine candidates are under development against the Sudan and Bundibugyo strains. Treatment is primarily based on supportive care: rehydration, correction of electrolyte imbalances, and management of organ failure. In addition, two monoclonal antibodies can also be administered, ideally as soon as possible after diagnosis, to reduce mortality. 

Ebola virus disease is currently in the news due to an outbreak of the Bundibugyo strain in the Democratic Republic of Congo and Uganda. This situation is worrying because it is a serious illness, the initial symptoms of which can resemble those of the flu, making initial diagnosis difficult. Furthermore, there is still no vaccine or validated specific treatment for this strain. It also occurs in fragile areas, where access to healthcare and medical follow-up may be limited, complicating efforts to control the epidemic. In response to this situation, the WHO has declared a Public Health Emergency of International Concern, without considering it a pandemic emergency. Globally, and particularly in France, the risk of the virus spreading is considered low.