Is Ebola endemic in humans?

Historically, Ebola has been considered a Supernatural disease, that is, a disease caused by a pathogen that humans get from other animals, often called spillover. Hemorrhage is the source of most emerging infectious diseases, and this is one of the reasons behind the recent focus on One Health, which believes that animal health, human health and environmental health are linked.

Ebola outbreaks appear to have increased in frequency in recent years and now there are two new Ebola outbreaks. One is in the North Kivu region of the Democratic Republic of the Congo. The other is in the N’Zerekore district of Guinea.

Genetic analysis from these events is now beginning to come in and the results are very interesting. Unlike most Ebola outbreaks, the current two events do not appear to be the result of new spillover events, but from contact with survivors. The evidence for this is the very high genetic similarity to viruses circulating in the same areas several years ago. According to the US CDC and the European Center for Disease Prevention and Control, the genetic analysis of the DRC revolution is linked to the 2018-2020 Ebola outbreak, which ended almost a year ago in June 2020. A much more detailed report on genetics the virus responsible for the Guinea revolution was recently published on the virological.org science blog and comes to the same conclusion.

How does this happen?

Ebola does not affect just one organ system, but it does attack a wide range of tissues and cell types. A few organs – including the eye, the central nervous system, and the testes – are thought to have a protective benefit, meaning they can tolerate the intrusion of foreign substances (such as virus grains). without stimulating an immune response. Thus, if the virus gets into one of these systems it can hide for a long time, even after a person has overcome it and developed an educational immune response. Ebola can also be sexually transmitted. Thus, there is a mechanism for the persistent virus in the testes to reach another person. Most men who have survived Ebola infection carry the virus in semen for hundreds of days and there is one known case where a second person became infected with Ebola after sexual contact with a person. survived nearly 500 days after the first infection.

This makes me wonder if Ebola has effectively become endemic in humans because nearly twenty thousand people are still living in Ebola, mostly in Africa? The answer is “probably”. Of course, spills from non-human animals are still possible and appropriate measures (such as cooking food thoroughly) are required. However, we may see more records in the future arising from infectious contact with survivors than we see from spill incidents. Of course, the types of communication that can emerge are very limited. Sexual communication is one. Direct contact with eye cigarettes, as may happen during surgery, is another way. Disease reactivation in a person with a chronic disease is also a theoretical possibility, but it must be very rare if it occurs at all.

Who Should Concern About Ebola?

Probably not you. Apart from those two places where Ebola is currently being closely monitored, there is little reason to be concerned about Ebola seizures. Even in places where the number of Ebola survivors is relatively high, the chance of anyone being exposed is small – much less than the chance of dying from the flu or an accident. It is a matter for public vigilance and health, however. As a communicable and highly fatal disease, it is important that when Ebola outbreaks occur, they are treated promptly to prevent a major spread. This is the responsibility of public health officials and organizations such as the World Health Organization. The rest of us don’t have to worry about it.