Five years ago the world was confronted by an ebola epidemic sweeping through parts of West Africa. This epidemic which raged from 2014 until 2016 caused more than 28,000 cases and 11,300 deaths mainly in Guinea, Sierra Leone and Liberia. Possibly given the circumstances of reporting in West Africa the real total may have been twice these figures. Since ebola was first identified in 1976 there have been at least 20 outbreaks of the disease as well as 10 major epidemics all concentrated in West Africa with the Congo involved in at least nine of them. Between 1976 and 2016 more than 34,000 cases of ebola were reported with over 13,000 deaths the majority in Sub-Saharan Africa including Sudan, Uganda, the Democratic Republic of Congo and Gabon.
And now ebola has returned with a vengeance to match and possibly exceed the 2014-16 outbreak. So far almost 1,000 people have been infected and 569 have died. Dealing with this present outbreak is proving exceedingly difficult. Partly this is because of its geographic location in the north-eastern part of the Democratic Republic of the Congo, an area marked by civil conflict and home to large numbers of armed groups and security forces who in some cases targeted health clinics, and partly because of cultural beliefs and practices among local people who do not understand the disease and are particularly unresponsive to what they see as the heavy handed measures of health workers, police and the military.
In such circumstances people have attempted to avoid identification and treatment particularly when such intervention interferes with traditional rituals governing illness, death and burial rites. Health workers have also struggled to move freely in areas of civil violence to track down infected people and in many ways have tended to treat ebola victims as a bio-threat rather than as individuals infected or at risk. Recently the WHO warned that there was a very high risk of the disease spreading not only within the Congo but also to Uganda, Rwanda and even the South Sudan. Effirts to control the outbreak have been severely hampered by local violence. Treatment Centres run by Medicin Sans Frontieres at Katwa and Butembo were recently attacked with the Butembo centre being torched and medical teams are now beginning to feel that they do not have enough trust from local communities to actively continue their work..
Ebola is a classic zoonosis or animal disease possibly nurtured and spread by fruit bats with occasional spill overs to apes, other animals and humans. Humans can become infected either by contact with the blood, secretions or other body fluids of infected animals such as chimpanzees, gorillas, monkeys, fruit bats as well as eating raw meat from such animals.
Since the last major outbreak in 2014-16 when the WHO and Western nations were subject to considerable criticism about their so-called measured response, we have developed a range of ebola vaccines, and while many remain to be fully tested or become widely available one has been found to be protective against ebola. Currently these experimental vaccines may protect people from infection but there still remains no specific drug for those who have caught the disease. So far perhaps as many as 90,000 people have been vaccinated but actual figures are hard to come by.
But did we learn anything from the last epidemic of ebola? In the epidemic of 2014-16, local, national and international responses left much to be desired. The spread of the disease was concentrated in Sierra Leone, Liberia, Guinea and Nigeria and one could be excused for thinking that the WHO and Western nation's reaction was simply to watch from afar believing that the epidemic was simply concentrated in a couple of remote African nations and would eventually burn itself out. Whether we have learnt from this and fully appreciate that to control an epidemic outbreak like ebola you have to respond quickly, identify and isolate treatment centres, treat those infected, trace contacts, understand the diffusion process and above all do all this in an understanding and humane manner that takes full recognition of local cultures and people.
There is little doubt that we live in a world of emerging and re-emerging infectious diseases all of which have the ability to spread rapidly in our mobile and highly interconnected world. When confronting outbreaks of infectious disease like ebola we need to fully appreciate five critical things.
Firstly, many emerging or re-emerging infectious diseases like ebola are zoonoses or animal diseases permanently maintained among animal species in isolated rural areas. Only rarely do such diseases spread to involve humans and usually this takes place when humans intrude on natural reservoirs of the disease in isolated forest areas or come into contact with infected animals. One such intrusion or contact can result in thousands of cases as was the case in the 2014-16 outbreak. There is little doubt that we need to better understand the ecological nature of a wide range of viruses that permanently exist amongst wildlife, how they are maintained and why they occasionally become more virulent and spread to other species. In addition, if we continue to believe that we are the dominant species in the world and that infectious diseases can simply be controlled or eradicated by anti-bacterial or anti-viral drugs then we fail to understand the resilience of the infectious world and their ability to adapt and mutate at the things levelled at them.
Secondly, we need to fully appreciate the implications of living in a highly mobile world where tens of millions of people cross national and international borders every day. The ability of infections to accompany such people is fast spreading. While ebola has been confined to parts of Sub-Saharan Africa there is evidence of secondary infections in parts of Europe caused by patients who travelled to Europe from West Africa in 2015-16.
Thirdly, the poor and most disadvantaged are much more likely to suffer and be affected by epidemics of infectious disease. In many parts of Africa and Asia the poor live closest to the animals that harbour a wide range of infectious diseases. Such people also enjoy a lack of access to health care and remain largely unaware of how infections spread.
Fourthly, our current medical arsenal of vaccines and drugs designed to confront infectious diseases always lags behind the ability of such diseases to mutate and adapt as well as to the emergence of new zoonotic infections. In the case of the 2014-16 epidemic the drugs used showed some promise but questions remain about their effectiveness in preventing death.
Finally, as the last ebola outbreak demonstrated, there seems to be a temptation among Western nations and world health authorities to stand back and watch from the sidelines ignoring such epidemics unless they finally believe that Western developed nations are in some ways threatened and that eventually infections like ebola will simply retreat back into their animal host.
The ebola epidemic currently underway in West Africa, is now the second largest on record and shows no signs of slowing up and is without doubt emerging as a public health issue of international concern. The risk of future ebola outbreaks will remain high as long as rural poverty throughout much of West Africa forces large numbers of people to rely on bush meat for survival and to hunt deeper in remote forest areas. But are we prepared for such epidemic encounters and can we cope? All this remains to be seen.