People are irrationally afraid of dangerous viruses. Proof? The Walking Dead, World War Z. And before that, the movies Contagion and Outbreak, the last being featuring a virus modeled on Ebola. The recent Ebola outbreak last year caused a lot of public concern, and still lingers, though it appears to be slowly coming under control. If you want to learn more, you can take a free MOOC, Ebola: Symptoms, History, Origins, which runs from February 2 to February 16. It is taught by Dr. Derek Gatherer who teaches bioinformatics and computational biology, and specializes in viruses at the University of Lancaster.
The Ebola virus outbreak in West Africa is very much the medical story of 2014, and I think it will continue to be so well into 2015
The course content will consist of 8 short video lectures of about 10 minutes each, and supplementary resources for further exploration. It will cover the following:
• Some basic virology, comparing Ebola to other viruses
• The symptoms and clinical aspects of Ebola
• The history of Ebola outbreaks and details on the present outbreak
• The genomic structure of the Ebola virus and treatments/vaccines
• The evolutionary origins of the virus and its epidemiology
The MOOC is appropriate for the general public, with some basic biology background being helpful for the technical jargon—though there will be glossaries and lecture notes provided and links to some resources to help provide further context.
Why is Ebola so Scary to the General Public?
With Ebola virus, if you are going to die that will probably be within 10 days of starting to develop symptoms
Clearly, Ebola is pretty frightening in the public’s imagination. Why is this so? Dr. Gatherer points to two reasons: the high mortality rate for those who contract the virus and show symptoms, and second the severity of the symptoms. He goes into further detail below:
Dr. Gatherer points out that the mortality rate would be lower if patients have access to modern medical facilities. Since the symptoms result in a loss of fluids, severe dehydration is a contributing factor to the mortality, and access to re-hydration drips and other support could help some patients.
Endemic vs. Epidemic vs. Pandemic?
First some definitions are in order:
• Endemic infectious diseases are ones that are always present in the population in more or less the same degree, but limited to a local population (e.g. chickenpox in the U.S., malaria in Africa) • Epidemic infectious diseases spread rapidly in a short period of time, but still limited to local populations (e.g. flus during flu season) • Pandemic infectious diseases have spread beyond local populations (e.g. HIV, H1N1 influenza). The WHO has a definition of six phases of a pandemic
According to the WHO, Ebola qualifies as a pandemic because it has spread to other regions outside of the initial outbreak (by the way there is also a fun cooperative board game called Pandemic). But as scary as Ebola may be, Dr. Gatherer reminds us that there have been other major pandemics in history: the bubonic plague, or “Black Death” in the 14th Century which killed between a third to half the population of Europe, and the so-called ‘Spanish Flu’ outbreak in 1928 which killed 40-50 million people.
Where did Ebola Come from and How do People Get It?
Dr. Gatherer points out that the Ebola virus is fragile and so cannot be transmitted through the air (unlike flu viruses). Instead, the Ebola virus is transmitted through wet bodily fluid from infected people, especially those who are going through the hemorrhagic phase and are bleeding, and their bodies continue to carry the virus after they are dead. Thus, the importance of following careful procedures in handling and treating infected patients.
Ebola virus is transmitted through wet bodily fluid from infected people, especially those who are going through the hemorrhagic phase and are bleeding, and their bodies continue to carry the virus after they are dead.
The Ebola virus did not originate in West Africa, where the current outbreak is occurring—instead, recent evolutionary analysis has indicated that the present outbreak strain originated in Central Africa and traveled to West Africa, probably via bats. Understanding the origins and evolution of the virus can be useful in predicting where it might arise next. Using the latest tools in evolutionary and computational biology, the best evidence suggests that bats are the reservoir population, the species in which the virus lives between “spillover” outbreaks into humans. Thus, despite how scary epidemics and pandemics can be, scientists’ toolkits have also improved to help understand and deal with these outbreaks. This may be our best hope in case of a zombie apocalypse.
Could a Virus like Ebola Wipe Out Humankind?
Although it is possible that Ebola could still continue to pop up in new areas, could it turn into a major pandemic? Not very likely, but Dr. Gatherer can paint a possible worst-case scenario:
“The Ebola virus gets to other cities in the developing world or other tropical cities which have shanty towns. So the problem is that if the virus, via air travel, arrives in South America or in Southeast Asia where some people live in conditions similar to those we see in west Africa, for instance where they do not have access to hygiene,and is very hot and there is a high population density and health services are poor, and so on – then we could see Ebola becoming an endemic disease of poor cities.”
But for the most part, Ebola is not his candidate for scariest-possible-pandemic. Instead, it would be a respiratory virus that could be transmitted via the air, such as SARS, but more deadly and widespread. And perhaps the relatively effective global response to SARS, influenza H1N1, and Ebola in developed countries shows how modern health systems and public health networks can combat many of these threats. But conversely, we also see how underdeveloped countries are at a severe disadvantage in dealing with these same threats. Thus, we have yet another reason for global development: to defend against civilization-ending pandemics. To learn more about Ebola, take Dr. Gatherer’s MOOC, Ebola: Symptoms, History, Origins, which starts February 2.
“Ebola is potentially going to be a much bigger problem in the tropical world in the future, so we need to be prepared.”