Historical origin: In 1976, an outbreak of infectious hemorrhagic fever occurred almost simultaneously in southern Sudan and northern Democratic Republic of Congo (formerly known as Zaire), when the mortality rates in both countries were 53% and 88%, and WHO medical experts isolated a new filovirus from patient specimens, morphologically similar to Marburg virus but with different immunological characteristics, and later named it after the Ebola River in the Democratic Republic of Congo, where the epidemic originated, as Ebola hemorrhagic fever (EBV). Ebola virus (EBV), and the resulting disease was called Ebola hemorrhagic fever (EBHF). Later, in the past 40 years, there were 24 outbreaks worldwide, with nearly 2,000 cases of infection and more than 1,300 deaths, and death rates of 53% to 88% reported by countries. The Ebola virus resembles a long fibrous filament with one end wrapped into a “rope buckle”, the shape of which is somewhat similar to the ancient Ruyi in China. It belongs to the filoviridae, single-stranded negative RNA virus, with 18,959 bases, molecular weight of 4.17 × 106. outside the envelope, the virus particle diameter of about 80 nm, size 100 nm × (300 ~ 1500) nm, infection ability of the virus is generally long (665 ~ 805) nm or so, there are branch-shaped, U-shaped, 6-shaped or ring-shaped, branch-shaped more common. There is a capsule membrane, and the surface has (8-10) nm long fibrils. The pure virus particle consists of a helical ribosomal riboshell complex containing a negative-stranded linear RNA molecule and four virulent structural proteins. There are five known subtypes: Zaire, Sudan, Bendibugio, Taï Forest and Leston, of which Leston is not pathogenic to humans, while infection with the remaining four subtypes will show typical clinical symptoms. Once the Ebola virus infects the human body, it secretes a glycoprotein that can disrupt your immune system and evade it, further dissolving all tissue cells in the body, causing red blood cells to clump together, blocking blood vessels, leading to bleeding and organ necrosis, and eventually leading to death. Reason for the outbreak: Previous Ebola outbreaks have occurred in eastern and central Africa. This time, it is raging in West Africa, which also caught the epidemic prevention departments of these countries off guard. Has it existed in West Africa for years? Could it be that there have been cases of Ebola in West Africa before, but they have not been confirmed. Stephen Moyes, an infectious disease expert at Columbia University in the United States, said, “A virus that has been present in West Africa for many years has not been confirmed. Professor Stephen Moss, an infectious disease expert at Columbia University, believes that “one or even more subtypes of the Ebola virus have probably existed in West Africa for quite a long time, but for various reasons, it did not explode until this year”. The danger of Ebola virus The current medical community generally believes that Ebola virus originates from animals in nature. Reasons include the fact that in October 1989, the Primate Quarantine Center in Lewiston, USA received a group of monkeys from the Philippines. During the quarantine process, one by one, these monkeys became ill and died. In the examination of the monkeys’ blood, it was found that these monkeys were infected with Ebola virus. Fortunately, this Leston Ebola virus is not pathogenic to humans and did not cause human illness. However, this finding once again led to the thought that Ebola virus may well also originate from non-human primates such as monkeys and orangutans like Marburg virus. However, it was later discovered that nonhuman primates were also victims of Ebola. during the 2001-2003 Ebola hemorrhagic fever outbreaks in Gabon and Congo, French scientists captured thousands of different animals, including bats, birds, and squirrels, in areas where the disease was endemic, and tested these animals for Ebola virus. As a result, evidence of the presence of Ebola virus was detected in 29 bats, and it was suspected that bats could be responsible for the transmission of Ebola virus. Although there is growing evidence that Ebola is transmitted from animals to humans. But to date, the exact source of the Ebola virus remains unclear. This year’s Ebola outbreak was caused by the Zaire-type Ebola virus (EBOV-Z). The “patient zero” of this West African Ebola outbreak was confirmed by CDC epidemiologists to be a 2-year-old boy who was reportedly bitten by a bat, which was found deep in the jungle of southeastern Guinea in May of this year and has since spread around through human contact. Medical experts believe that in each Ebola outbreak, the “patient zero”, the initial patient in the outbreak, may have been caused by accidentally eating or handling an animal infected with Ebola virus. At this stage, experts believe that the Ebola virus has been hidden in nature and may have originated from certain species of bats, such as the fruit bat. A 1983 study showed that 9.7% of healthy people in Ebola-affected areas were positive for Ebola, and further epidemiological investigations also confirmed that people living in the tropical jungle were generally more positive for the virus than urban populations. The destruction of nature by mankind can be described as an all-round extinction by land, sea and air, with atmospheric pollution, industrial emissions, declining air quality, increasing amounts of toxic gases, dirty rainwater and environmental destruction. In Sierra Leone and neighboring countries, in recent years, deforestation and excavation have become more serious, and large areas of forests have been deforested and burned in order to reclaim arable land for rice cultivation on a large scale; from cutting down plants in the mountains, to quarrying and digging soil for construction under the mountains, to mining resources underground. First of all, this destruction reduces the biodiversity of these countries, and the ecosystem becomes increasingly simple and fragile; at the same time, the loss of living space for wild animals will carry a variety of viruses into the human habitat, coupled with human expulsion to hunt and prey on these wild animals. This results in close direct human contact with these viruses, to which humans are defenseless, leading to the spread and outbreak of viruses in the population. Once there is an epidemic outbreak of infectious diseases, the poor local health conditions and the low literacy level of the residents are unable to recognize the danger of infectious diseases, let alone early detection, early reporting, early isolation and early treatment, coupled with the very fragile prevention and control system of infectious diseases in these countries, which cannot immediately attract high attention, resulting in the gradual deterioration of the epidemic among the population and a large number of fatal cases. Routes of transmission Here in West Africa, funeral practices create more opportunities for infection, and funerals can even be referred to as “super transmission events”. Sierra Leone has a great respect for the deceased, and funeral practices here require close proximity to the body of the deceased, and before burial, the body needs to be thoroughly washed by relatives and any residual urine and excrement sucked out of the body. Yet these bodies are highly contagious, and the process of touching, kissing, and washing the remains has made many innocent people infected, and this has become a very important route of transmission. Ebola is spread through wildlife Sierra Leone has poor medical conditions and there are only 106 registered clinicians in this small West African country, and because of the Ebola outbreak, these people led the country’s population to take the lead in the fight against the Ebola virus. They have become the country’s heroes, and 12 physicians have already given their lives in just a few months. Yet in a West African country with only a few hundred doctors in training, the Ebola outbreak was preceded by the deaths of a large number of medical personnel. And now millions of Africans are threatened with the next wave of the epidemic.