Health authorities in the Democratic Republic of the Congo and Uganda are working to contain an Ebola outbreak that has so far resulted in 246 suspected cases and 88 deaths. The outbreak began in Ituri province in eastern DRC, but cases have been detected elsewhere in the country and in neighbouring Uganda. On Sunday, the World Health Organization declared the outbreak a public health emergency of international concern, urging robust efforts to limit its spread.
What is Ebola?
Ebola is a highly contagious and often fatal disease caused by different viruses mostly associated with fruit bats. The infection often results in viral haemorrhagic fever. Since it first emerged in 1976, more than 40 outbreaks have been documented, with this being the 17th outbreak in the DRC. Outbreaks result from zoonotic spillover, where the virus transmits from animals to humans. Infected humans then pass the disease to others through bodily fluids such as vomit, blood, and semen. Symptoms include fever, fatigue, muscle pain, and headache, followed by vomiting, diarrhoea, rash, and internal and external bleeding. The disease has a 50% death rate. There are four types of Ebola that affect humans: Zaire, Sudan, Bundibugyo, and Tai Forest. The WHO says the latest outbreak involves the Bundibugyo virus, with only two previous outbreaks of this strain in 2007 and 2012.
Why is this outbreak causing such concern?
The strain involved is rare, with no specific vaccine or therapeutics available. The existing Ervebo vaccine is not effective against the Bundibugyo virus. Additionally, conflict in the DRC complicates containment efforts. Dr Simon Williams, an infectious diseases expert at Swansea University, notes that the high case fatality rate makes this outbreak more worrying than others. While Ebola is less transmissible than Covid-19 or measles, it is much more severe and can be fatal to anyone, not just high-risk groups. Infection control typically involves isolating affected individuals in treatment centres, but conflict and targeting of healthcare facilities may discourage people from seeking care, increasing the risk of transmission.
Why was the outbreak not detected sooner?
The outbreak began last month, with the earliest known suspected victim developing symptoms on 24 April and dying three days later. Health authorities were only alerted through social media on 5 May, by which time 50 people had already died, according to the Africa Centres for Disease Control and Prevention. Slow detection allowed the outbreak to spread. Dr Jean Kaseya, director general of the Africa CDC, warns that any delay in responding to an Ebola outbreak can have catastrophic consequences. Dr Anne Cori of Imperial College London adds that the large number of detected cases suggests the outbreak went undetected for several weeks or months, making standard control measures like contact tracing considerably more difficult, especially in a conflict-affected setting.
How big could this outbreak get?
The outbreak could potentially grow much larger. While it began in Ituri, two confirmed cases have been found in Uganda, both in individuals who travelled from the DRC. One of them died at a hospital in Kampala. The WHO fears that the high proportion of positive cases among those tested, combined with the spread to Kampala and deaths in Ituri, points towards a potentially much larger outbreak than currently detected. There are significant uncertainties about the true number of infected persons and geographic spread.
