Published 24th August 2018
Democratic Republic of Congo
On the 24th July of this year, the 9th Ebola outbreak in the Democratic Republic of Congo (DRC) was declared over. Centred around the town of Mbandaka in North-Western DRC, this epidemic killed just over 30 individuals before it was successfully controlled. The relief at its containment was short-lived, however, as only a week later news of a new, completely unrelated outbreak of Ebola was being received from Mangina, a town in North Kivu, DRC – over 1,500 miles away to the east. This 10th DRC Ebola outbreak has already outstripped its previous epidemic: more than 100 individuals are suspected of being infected; almost 60 people have died.
What makes this outbreak different?
There are several factors that conspire to make this latest Ebola epidemic particularly concerning. Firstly, North Kivu is one of the most densely populated regions of the country. As more than 8 million people live in the area, the potential for mass infections is much greater than during the previous outbreak. Furthermore, affected towns such as Beni, are trading centres with the nearby Ugandan towns of Kasese and Fort Portal. As was seen during the West African Ebola outbreak of 2013/16, patients infected with the virus were especially difficult to follow-up and quarantine when several countries were involved.
The most important reason for concern for this epidemic, however, is that Eastern DRC has been subject to on-going military action for many years making WHO’s efforts in the area at best extremely challenging and at worst, impossible. Up to 130 armed militias have been identified as causing conflict in the region. Amongst the most feared is the ADF – the Allied Defence Force – a Ugandan Islamist rebel group. Formed in 1989, the ADF were initially based in the Rwenzori Mountains of Western Uganda before being driven into eastern DRC. Their crimes include mass murders and maimings, as well as the use of children as soldiers and sex slaves. More recently they were responsible for an attack on UN peacekeepers at the end of 2017, during which 53 peacekeepers were injured and 14 killed – described as the worst attack on UN forces in the last quarter century.
These unremitting conflicts by the many militias have led to internal displacement of a million Congolese and a high rate of border traffic into Uganda and Rwanda, increasing the risk of transmission of Ebola into neighbouring countries. The WHO has already issued Preparedness Support Teams into adjoining countries in an attempt to limit the possibility of cross-border infections. It is the effect of the conflicts within DRC that presents the greatest difficulty to controlling the outbreak, however. Attempts to identify, quarantine and treat patients will be severely hampered by the ongoing military action. Moreover, there are several regions designated as ‘red zones’ in which the danger posed to healthcare workers is so great that they are deemed as no-go areas. Despite this, there are reports that several workers from Doctors Without Borders are risking following up 48 contacts of Ebola patients so far identified in red zones.
The Ebola vaccine VSV-ZEBOV, previously used in recent epidemics, is being rolled-out to high risk individuals. As in prior epidemics, a ring-fence strategy is being used to target those in greatest need of the immunisation. When an Ebola patient is identified, all of their recent contacts are vaccinated, as are the contacts of the contacts. Thus two rings of vaccinated people are constructed in an attempt to protect those unvaccinated from being infected with the deadly virus. So far, over 1,500 people have been vaccinated in 10 rings of contacts. Healthcare workers have also been vaccinated as they are at particular risk of becoming infected from their patients – and also once infected, healthcare workers can sadly easily infect other individuals for whom they care. As with previous epidemics, healthcare workers have been proportionately hardest hit by the virus, 17 have so far been reported.
Several other potential therapies for Ebola have been approved for use in the DRC. Two therapies contain antibodies that may be helpful in controlling an infection once established. Isolated from an Ebola survivor in 1991, the medication termed mAB114 contains an antibody that can stop the Ebola virus from entering the body’s cells. So far only limited human studies have occurred with mAB114: a phase one clinical trial has been performed which showed that it was safe to use in humans. Other than that, it has only been used in monkeys with some success. Another antibody-based therapy is ZMapp – which contains three antibodies. This medication had limited use during the West African epidemic, but the number of patients in which it was trialled was too small to say whether ZMapp helped or hindered.
Another two drugs that have been approved in DRC work against Ebola in a different way. The drugs, Remdesivir and Favipiravir, are able to interfere with Ebola’s capacity to make copies of itself. In an analogous way to how the HIV virus was successfully treated, ‘false building-blocks’ are incorporated into the replicating Ebola virus, resulting in the production of useless viruses. Although the evidence for Remdesivir working with Ebola is slight so far, Favipiravir has successfully protected several types of monkeys when infected with the virus.
Although the epidemic is at a very early stage, there are reasons to be concerned for DRC and its neighbours. Conflict is very likely to interfere with the WHO’s efforts to control the outbreak; efforts that have been met with local resistance and hostility in the past, but have ultimately proved successful. With the added challenge of widespread, on-going military action, it is unclear what will be possible, and how large the Ebola outbreak will eventually become.
Written by Dr. Simon Worrell, Head of Medical Communications, Healix International.