Ebola outbreak in the DRC

The World Health Organization has declared an Ebola outbreak in the Democratic Republic of Congo (DRC) a public health emergency of international concern, with more than 130 reported deaths in the African nation. Petra Merzan investigates…

Ebola is an acute disease caused by orthoebolaviruses. Transmission occurs through close contact with organs or bodily fluids of an infected animal, usually fruit bats, and outbreaks are often linked to animal-to-human contact, followed by human-to-human contact.

The disease was first reported in 1976, and since then has given rise to 40 confirmed outbreaks, with a staggering fatality rate of over 50%. Its incubation time is around 8 to 10 days, but that can vary greatly. Symptoms of Ebola typically begin with fatigue, fever, muscle pain, and headaches, and progress into vomiting, diarrhoea, a rash, and both internal and external bleeding. Given the non-specific array of early symptoms, diagnosis is more common in the late stages of infection, when the virus is most contagious.

You may remember the Ebola outbreak in West Africa between 2013 and 2016. It was the largest so far, and 11,325 people died. In that instance, the disease was caused by the Zaire species of orthoebolaviruses. It is the most well-documented strain of the virus, and has also driven the highest number of global cases.

The current outbreak affecting the DRC - and to a lesser extent neighbouring Uganda - is caused by the Bundibugyo species, which is known to have a lower mortality rate than the Zaire strain. Bundibugyo is thought to kill between 30% and 40% of those who contract it. Although it is not as lethal, it is poorly understood - partly because its epidemiology is well less characterised than its cousin Zaire.

In fact, there is no vaccine that can tackle the current crisis. “The licensed Ebola vaccines only protect from infection with Ebola Zaire, the species which historically has caused large outbreaks most frequently,” according to Anne Cori and colleagues at the Imperial School of Public Health. “There are currently no vaccines licensed for Bundibugyo or other species. This makes an outbreak caused by Bundibugyo potentially more challenging to contain,” they added.

The absence of pharmaceuticals makes community engagement crucial to managing the outbreak. Contact tracing, isolation, treatment of infected patients, and safe burials - using PPE - are essential as the world awaits a potential vaccine candidate.