Ebola virus Disease / Ebola hemorrhagic Fever

Ebola virus disease (EVD) or Ebola hemorrhagic fever (EHF) is the human disease caused by the Ebola virus. Ebola virus Symptoms typically start two days to three weeks after contracting the virus, with a fever, sore throat, muscle pains, and headaches. Typically nausea, vomiting, and diarrhea follow, along with decreased functioning of the liver and kidneys. At this point, some people begin to have bleeding problems.

Ebola virus host involved in Ebola virus disease / Ebola hemorrhagic fever

Natural EBOV infections are primarily localized to the humid rain forests of Central and western Africa as well as the Philippines. While the precise mechanism of natural virus transmission to humans and non-human primates (NHPs) remains elusive, there are some indications that bats may constitute the natural reservoir and primary source of infection. Bats have widespread diets, including nectar, fruit, fish, frog and insect. Some species like to eat animal blood and other bats. The gorillas and other primates will be infected by them where Ebola virus virion has been left.

In the case of 1976 and 1979 Ebola virus outbreak, bats are associated with transmission. In 2002-2003, scientists make an effort to find Ebola virus host. They captured thousands of animals from Gabon and the Republic of the Congo where Ebola virus has broken up. Among them, there were 679 bats, 222 birds and other mammals. As a result, Ebov virus was found in 3 types of bats (Hypsignathus monstrosus, Epomops franqueti, and Myonycteris torquata) and these bats didn't have Ebola virus Symptom. So, bats are proved to be Ebola virus natural host. The second host can be primates, pigs, insects, plants.

People may then become infected through contact with infected animals, either in the process of slaughtering or through consumption of blood, milk, or raw or undercooked meat. The virus is then passed from person to person through direct contact with the blood, secretions or other bodily fluids of infected persons, or from contact with contaminated needles or other equipment in the environment.

Ebola virus disease / Ebola hemorrhagic fever transmission

Bats are believed to be the natural host of Ebola virus. There are several ways in which Ebola virus can be transmitted to others, including direct contact with infected blood or secretions and exposure to objects that have been infected.

Human infect Ebola virus via close contact with the blood, secretions, organs or other bodily fluids of infected animals. Ebola virus spreads in human via a human-to-human transmission. When a broken skin or mucous membranes is exposed to bodily fluids, secretions, organs of infected people, people will be infected. And an indirect contact with infected fluids also can lead to Ebola virus infection.

In Africa, before being buried or cremation, the deceased person's body is usually washed by mourners. This custom increases the transmission of Ebola. Health-care workers have frequently been infected while treating patients with suspected or confirmed EVD.


Approximately 2–8 days following initial Ebola virus infection, patients rapidly develop a fever and other Ebola virus symptoms (headache, weakness, sore throat), eventually progressing to a maculopapu -lar rash and signs of impaired coagulation. Unfortunately, clinical EBOV cases are often misdiagnosed since the incubation time and flu-like symptoms are common to several other infectious diseases.

If having some Ebola virus symptoms of Ebola virus disease, the patient should be isolated first. Samples should be sent to a laboratory to confirm infection. Because samples from patients are a source of infection risk for others, testing is conducted under maximum biological containment conditions.(picture below from CDC)

Timeline of Infection Diagnostic tests available
Within a few days after symptoms begin Antigen-capture enzyme-linked
Polymerase chain resction (PCR)
Virus isolation
Later in disease course or after recovery IgM and IgG antibodies
Retrospectively in deceased patients Immunohistochemistry testing
Virus isolation

Ebola virus disease / Ebola hemorrhagic fever treament

There is no any specific treatment. Even if EBOV is identified early during infection, effective, anti-viral therapies are not currently available. Instead, treatments are primarily supportive and include hydration, blood volume maintenance, pain management, as well as interferon regimens when available. Currently there is a lack of licensed Ebola virus vaccines as well as pre- and post-exposure treatments. Recent increases in the frequency of natural human Ebola virus infections and its potential use as a bioterrorism agent makes vaccine development a priority for many nations. Significant progress has been made in understanding the pathogenesis of Ebolavirus infection and several promising vaccine candidates were shown to be successful in protecting NHPs against lethal infection.