Ebola: Background and current Status

Science and Technology

Image Credit: bhossfeld (CC0)

Ebola is a highly virulent viral disease that spreads to humans from infected animals. Predominantly spreading throughout Africa, it was relatively obscure until 2013. Starting in 2013, a large scale outbreak shocked the world with the possibility that it could spread trans-nationally. Although it does seem that the defences against Ebola have been strengthened since that outbreak, there is still a way to go. Ebola is currently spreading in the DRC and healthcare officials are facing similar problems to the 2013-2016 epidemic.

Picture the scene. It is the DRC during 1976 in the small village of Yambuku. A schoolmaster has contracted a highly virulent infection which is as of yet unknown to modern medicine. This schoolmaster has become patient zero and will subsequently enable the pathogen to spread to 318 other people causing an outbreak with a mortality rate of 88%.

The infection causes many symptoms most of which are hard to distinguish from other endemic diseases. These include: headache, muscle and joint pain, sore throat, muscle weakness, diarrhoea, vomiting and rashes. In some cases internal haemorrhaging can occur causing bleeding from bodily orifices. Instead of naming the illness after a symptom, scientists named it after a geographical feature. Yambuku is situated near to a tributary of the Congo River called Ebola, which seemed like a fitting title.

Although highly infectious, Ebola passes directly from person to person due to bodily fluid contact. This can be prevented relatively easily using disinfectants such as chlorine on contaminated surfaces. Changes in people’s hygiene routines are very effective in curbing transmission; if people do not touch other sick people or anywhere sick people have touched, then the disease shouldn’t spread. Moreover, the efficacy of using vaccines to prevent epidemics have not been proven.

Since discovery, the five strains of EVD (Ebola Virus Disease) have caused 22 outbreaks with varying mortality rates, from 20% to 90%. The outbreaks start due to human contact with an infected animal. Pteropodidae fruit bats have been identified as the animal reservoir but the evidence for this is shakey. Other animals e.g. primates such as Chimpanzees have also been shown to start epidemics. This usually occurs due to people eating bush meat after hunting live or scavenging for dead animals. One commonality between these outbreaks is that they have been historically small-scale.

However, as most probably remember, this all changed during the 2013-2016 outbreak in which 11301 people died. The outbreak spanned three West African countries: Sierra Leone, Liberia and Guinea. This was worlds apart from previous epidemics in which the virus only infected a few hundred people and didn’t travel far beyond the epicentre. There were numerous reasons for this increase in geographical range. In the last few decades, international travel has become increasingly common throughout Africa. This has made it easier for infected people to travel further afield. Proximity to infrastructure also played a part as the first cases were not placed in the middle of impenetrable forests. Moreover: rampant poverty, a deep distrust of scientists and healthcare workers (leading to an absence of diagnostics, quarantining and treatments), armed conflicts, local customs (including an insistence to physically touch and wash dead bodies) and an unacceptably belated response from the international community formed the perfect conditions for the first large scale Ebola outbreak.

The epidemic was declared over in 2016 after the transmission rate fell below replacement level. This was in part due to the influence of NGOs and governments, foreign and domestic, who were able to change local attitudes regarding the handling of the disease.

Ebola isn’t gone and forgotten. Currently, an outbreak is occurring in the DRC that has already claimed the lives of over 90 people. On the positive side, the response to this outbreak has been much faster than we saw in 2013; the WHO did not take 6 months to respond this time! Hopefully the spread will not be allowed to quickly get out of hand.

 “The transmission rate appeared to be slowing down due to communities responding quickly to prevent the spread” –  said Jose Barahona, Oxfam’s country director for the DRC.

However, Africa is a poor continent and the DRC suffers from many problems facing the countries affected by the 2013-2016 outbreak. Large scale poverty, poor quality infrastructure and unfit sanitation systems provide significant obstacles to epidemic prevention.

“These new cases in urban areas mean we’re not out of the woods yet. In big cities, people come into contact with far more people, especially in a major trading place”. “It’s also of real concern that three cases of the virus were found in a place where armed groups are highly active” added Barahona.

It would seem that the ways authorities respond to Ebola, thankfully, have improved since 2013. Unfortunately, as long as these outbreaks continue to happen in poor countries, there is still much to improve. Watch this space to see how this outbreak plays out. Have enough lessons been learnt since 2013?