Ebola Virus Disease : Symptoms, Causes, Diagnosis and Management

Ebola Virus Disease : Symptoms, Causes, Diagnosis and Management

Ebola Virus Disease (EVD)   first originated in Sudan and the  Democratic Republic of Congo. The disease typically occurs in outbreaks in tropical regions of Sub Saharan Africa. Fewer than 1000 people have been infected every year from 1976 till 2013. Ebola virus was first detected in 1976 during outbreak of Ebola haemorrhagic fever in Zaire and Sudan. The name of the disease originates from one of those first recorded outbreaks in 1976 in  Democratic Republic of the Congo (then Zaire), which is situated on the Ebola River.

  • Ebola Virus Disease (EVD) also known as Ebola haemorrhagic fever(EHF) is one of the viral haemorrhagic fevers which affects a person’s blood system
  • It is a severe, often fatal illness in humans and non human primates (monkeys, gorillas, and chimpanzees)
  • It is caused by infection with virus which  is transmitted to people from wild animals and spreads in the human population.
  • EVD is fatal in, upto- 90% of infected cases .
  • EVD outbreaks(sudden occurrence of disease) are known to occur primarily in villages of  Central and West Africa, near tropical rainforests.
  • The largest outbreak is the  2014 West Africa Ebola Outbreak, which has affected Guinea, Liberia, Sierra Leone and Nigeria.
  • Severely infected patients require intensive supportive care. No specific treatment or vaccine is available for this disease.

Symptoms of Ebola Virus Disease

  1. Fever
  2. Headache
  3. Weakness
  4. Joint and muscle pain
  5. Diarrhoea
  6. Vomiting
  7. Pain in stomach
  8. Loss of appetite

This disease further progresses to bleeding phase which causes external bleeding from eyes, nose ears as well as bleeding inside the body.

Symptoms may appear from 2 to 21 days after exposure to virus, though 8-10 days is most common period after exposure to Ebola virus.

Causes of Ebola Virus Disease

EVD is caused by four of five viruses in the genus Ebola virus, family Filoviridae, order Mononegavirales. The four disease-causing viruses in humans are as follows:
  1. Bundibugyo Ebola virus (BDBV)
  2. Zaire Ebola virus/Ebola virus (EBOV)
  3. Sudan Ebola virus (SUDV)
  4. Taï Forest Ebola virus (TAFV)

BDBV,EBOV,SUDV are most dangerous viruses as well responsible for causing large number of outbreaks in Africa.

The fifth virus called Reston Ebola virus (RESTV) is known to cause disease in non human primates (monkeys, gorillas, and chimpanzees)
A. Primary Source of Infection-The virus is transmitted from animals to humans. The virus is zoonotic (animal-borne) with bats being the most likely reservoir of infection.

B. Secondary Source of Infection-The virus can be transmitted from human-to- human through-

  1. Direct contact with  the body fluids such as blood, sweat, saliva, semen or other body discharges of an infected person.
  2. Exposure to objects like needles that have been contaminated with infected person.
  3. The dead body of the infected person can also be a source of infection.
Facts about Transmission
  • Ebola can’t be transmitted through air.
  • It can’t be transmitted through water.
  • It can’t be transmitted through food.
This clearly states that it is not a food-borne, water- borne and an air-borne disease.
Risk of Exposure

During the outbreak, those at higher risk of infection are-

a) Health workers.
b) Family and others who are in close contact with infected individuals.
c) Mourners who come in direct contact with the bodies of the deceased in burial ceremonies.
d) Travellers who visit   disease prone areas.

Diagnosis of Ebola Virus Disease

It is difficult to diagnose the disease in early stages of infection as the early symptoms are non specific to Ebola virus infection. However, it can be diagnosed through several lab tests such as-

  • Antibody-capture enzyme linked immunosorbent assay (ELISA)
  • Antigen detection tests
  • Polymerase Chain Reaction(PCR)
  • Virus isolation by cell culture.
  • Electron microscopy

Management of Ebola Virus Disease

No vaccine for Ebola Virus Disease is available. Efforts are going on to develop a vaccine. There is no specific treatment for this disease. However, the standard treatment for Ebola virus Disease includes an intensive supportive therapy. This consists of:

  • balancing the patient’s fluids and electrolytes
  • maintaining their oxygen status and blood pressure
  • treating them for any other infections

It is very important to provide the treatment/supportive care of Ebola haemorrhagic fever (EHF) timely, since it is difficult to diagnose the disease in the early stages of infection. The early symptoms such as headache and fever are nonspecific and can be easily misunderstood for any other disease. The prevention of this disease  is a challenging task because it is still not certain as to how people are infected with  EHF.

Prevention of Ebola Virus Disease

The primary preventive measures comprises of isolation   and barrier nursing techniques. Isolation separates sick people with a contagious disease from people who are not sick.

Quarantine, a state of enforced isolation, is effective in decreasing the spread of disease and illnessespecially in the case of communicable diseases .   The movement of people who were exposed to a contagious disease is restricted to come in contact with those who are healthy. Generally, the duration of quarantine period is the length of disease’s incubation period (period between the infection and appearance of symptoms) which is 2-21 days in case of Ebola virus  disease.

Barrier nursing techniques include:

  • Wearing  protective clothing (such as masks, gloves, gowns, and goggles).
  • Use of infection-control measures (such as complete equipment sterilization and routine use of disinfectant).
  • Fumigation of   environment and disinfection of   surroundings. The virus cannot survive disinfectants, heat, sunlight, detergents and soaps.
  • Dead bodies can transmit Ebola. Don’t touch them without a protective gear or better avoid them altogether.
  • Wash your hands with soap or use sanitizer.
  • http://www.who.int
  • http://www.cdc.gov