What is Ebola disease?
Last Update: February 28, 2023
Medically reviewed by Angelena Maria Labella, MD
Both humans and nonhuman primates are vulnerable to the lethal and uncommon “Ebola disease”. Ebola virus disease (EVD) affects viruses that are basically present in sub-Saharan Africa. Direct contact with an infected animal (such as a bat or nonhuman ape) or a sick or dead body that has the Ebola disease virus can cause Ebola Disease in humans.
The Ebola vaccine, ERVEBO®, has received FDA approval for its use in the treatment of ebola disease. Only the Zaire ebolavirus species of ebolavirus has been confirmed to be safe and protected by the ERVEBO vaccination.
1. What is Ebola Disease Virus:
There are sporadic outbreaks of the deadly Ebola virus disease (EVD), which is primarily present in Africa. Ebola Disease mostly affects nonhuman primates and people (such as monkeys, gorillas, and chimpanzees). It is brought on by a disease with a subfamily of the ebola disease virus:
- Ebola virus
- Sudan virus
- Bundibugyo virus
- Bombali virus
- Reston virus
Only four of these (Ebola, Sudan, Ta Forest, and Bundibugyo viruses) are associated with human disease. Pigs and nonhuman primates can get sick from the Reston virus, but humans do not get affection from it yet. The Bombali virus was originally discovered in bats in 2018, and scientists are still unsure if it may sicken humans or animals.
In what is now the Democratic Republic of the Congo, the Ebola disease virus was initially found in 1976 close to the Ebola River. Since then, the virus has occasionally infected people, causing outbreaks in numerous African nations. Scientists are unsure of the origins of the Ebola virus. They think Ebola disease is animal-borne and that bats or nonhuman primates are the most plausible sources of infection based on similar viruses. Apes, monkeys, duikers, and humans are just a few of the numerous animals that the virus can infect and spread to.
The virus first infects people through contact with infected blood, body fluids, and tissues of animals. Then, the Ebola disease virus spreads to new victims when they come into contact with the bodily fluids of an Ebola Disease patient or victim. This might develop if a person touches some infectious materials or infected bodily fluids. The virus then gets into the body through rashes or weak eye, nose, or mouth mucous membranes. After the disease has passed, the virus may still be present in some bodily fluids, such as semen.
2. Signs and Symptoms of Ebola disease:
After coming into contact with the virus, symptoms of Ebola Disease can start anywhere between 2 and 21 days later, on average 8 to 10. The disease usually starts off with “dry” symptoms like temperature, aches and pains, and fatigue. These symptoms before progress to “wet” symptoms like diarrhea and vomiting as the patient gets sicker.
The following list of basic Ebola disease signs and symptoms may include some or all of the following:
- Aches and pains, including painful headaches and painful muscles and joints
- Fatigue and weakness
- Unwell throat
- Reduced appetite
- Gastrointestinal signs such as nausea, vomiting, and cramping
- Unusual bleeding, bruising or hemorrhaging
- Red eyes, a skin rash, and hiccups are some more signs (late-stage)
The signs and symptoms of many other common diseases, like flu, malaria, or typhoid fever, might be similar to Ebola virus disease (EVD).
EVD is a rare yet serious and frequently fatal illness. Good supportive clinical treatment and the immunological response of the patient are essential for EVD recovery. According to studies, antibodies (immune system proteins that recognize and kill invasive viruses) can still be found in the blood of Ebola disease virus survivors up to 10 years after recovery. It considers that survivors have some protection from the strain of Ebola disease that initially sick them.
Clinical differentiation of EVD from other infectious conditions like meningitis, typhoid fever, and malaria can be difficult. Pregnancy and the Ebola virus both exhibit a number of comparable symptoms. Pregnant women should preferably be quickly tested if Ebola is suspected due to hazards to the unborn child.
Several diagnostic techniques are used to determine that symptoms are brought on by Ebola virus infection:
- Enzyme-linked immunosorbent test for antibodies (ELISA)
- Tests for antigen-capture detection
- Test for serum sensitivity
- Polymerase chain reaction for reverse transcription (RT-PCR) is to evaluate virus identification by cell culture with electron microscopy.
The choice of diagnostic tests should be carefully considered, taking into account technological requirements, disease frequency and prevalence, and the social and medical implications of test results. It is highly advised that diagnostic procedures that have undergone independent, global evaluation be given serious consideration.
Currently advised tests by the WHO include:
- Nucleic acid tests (NAT) that are fully or partially automated are used for regular diagnostic management.
- Quick antigen detection tests for use in remote locations without easy access to NATs. For screening purposes as part of surveillance efforts, these tests are advised; however, reactive testing should be verified with NATs.
- The following are the preferred diagnostic specimens:
- Entire blood is drawn from conscious, symptomatic individuals and preserved in ethylenediaminetetraacetic acid (EDTA).
- oral fluid samples are obtained from deceased patients or when blood collection is not possible and stored in a universal transport medium.
Because patient samples pose a significant biohazard, laboratory testing on non-inactivated samples must follow the strictest biological containment guidelines. All biological samples should be transported both locally and internationally using the triple packaging technique.
Supportive therapy, which involves addressing particular symptoms and rehydrating patients with oral or intravenous fluids, increases survival. The evaluation of a variety of prospective treatments is including immunological therapies, pharmacological therapies, and blood products.
The first-ever multi-drug randomized control trial was conducted in the Democratic Republic of the Congo’s 2018–2020 Ebola outbreaks as part of an ethical framework created after consultation with subject-matter experts and the DRC to assess the efficacy and safety of drugs used in the treatment of Ebola patients.
Inmazeb and Ebanga, two vaccines, were authorized by the US Food and Drug Administration in late 2020 for treating Zaire ebolavirus (Ebolavirus) infection in adults and children.
5. Transmission of Ebola disease:
Scientists believe that contact with an infected animal, like a fruit bat or nonhuman monkey, results in the initial ebola transmission to humans. It is referred to as an overflow incident. The infection then spreads from person to person, possibly impacting a massive population.
Direct contact (such as through cuts and bruises or the mucous membranes of the eyes, nose, or mouth) with any of the following can spread the virus:
Blood or bodily fluids (including urine, perspiration, stool, vomit, breast milk, amniotic fluid, and semen) cause ebola
Objects that have been infected with bodily fluids from a person who has EVD or has died from it, including clothing, bedding, needles, and medical equipment.
Fruit bats or non-human primates with the disease (such as apes and monkeys)
People who contract Ebola disease do not immediately show any signs or symptoms of infection. The interval between being infected with an infection and showing symptoms is known as the incubation period.
Once a person exhibits Ebola disease symptoms, they are no longer contagious to others.
Furthermore, it is unknown if the Ebola virus may spread through food. However, the handling and ingestion of wild animal meat or of hunting wild animals that have the Ebola virus can spread the disease in several regions of the world. There is no proof that insects, including mosquitoes, may spread the Ebola virus.
6. Risk Factors:
Family members and acquaintances who come into close contact with Ebola patients and healthcare staff who do not practice effective infection control while caring for these patients are most at risk of contracting the disease. When people come into contact with infected blood or bodily fluids, Ebola can spread.
Travelers and the general public who have not provided care for or been in close contact (within 3 feet or 1 meter) with an Ebola patient are at low risk of contracting the disease.