Ebola Virus

About Ebola Virus

• Ebola, previously known as Ebola hemorrhagic fever, is a rare and deadly disease caused by infection with one of the Ebola virus strains.
  • Ebola can cause disease in humans and nonhuman primates (monkeys, gorillas, and chimpanzees).
• The Pathogen: It is caused by viruses belonging to the Orthoebolavirus genus of the Filoviridae family.
• Ebola Virus Viral Strains: Six species of Orthoebolaviruses have been identified.
  • Zaire, Sudan, Bundibugyo, and Taï Forest viruses are known to cause disease in humans,
  • while Reston and Bombali viruses have not caused disease in humans.
• Natural Reservoir: Fruit bats of the Pteropodidae family are considered the natural hosts of the Ebola virus.
• Incubation period: The incubation period of Ebola disease ranges from 2 to 21 days, while symptoms usually begin within 5 to 15 days after exposure.
• Transmission:
  • Animal-to-Human Transmission: The virus spreads through contact with infected wild animals such as fruit bats, monkeys, gorillas, porcupines, and forest antelopes.
  • Human-to-Human Transmission: Infection spreads through direct contact with blood, secretions, organs, or other bodily fluids of infected persons.
  • Contaminated Materials: The disease also spreads through contaminated surfaces, clothing, bedding, and burial practices involving infected bodies.
• Symptoms:
  • Early Symptoms: Patients may develop fever, fatigue, headache, sore throat, muscle pain, and malaise.
  • Advanced Symptoms: Vomiting, diarrhoea, abdominal pain, rash, and impaired kidney and liver functions may appear later.
  • Severe Condition: Some patients may develop internal or external bleeding, confusion, irritability, and aggression.
• Diagnosis:
  • Laboratory Tests: Ebola infection is confirmed through polymerase chain reaction (RT-PCR) assay, ELISA, antigen detection tests, and virus isolation methods.
  • Clinical Difficulty: Early symptoms resemble diseases such as malaria, typhoid, and meningitis, making diagnosis difficult.
• Treatment:
  • Supportive Care: Early rehydration, fluid balance, pain management, and treatment of co-infections improve survival chances.
  • Approved Therapeutics: WHO recommends monoclonal antibodies such as mAb114 (AnsuvimabTM) and REGN-EB3 (InmazebTM) for Ebola virus disease.
  • Current Limitation: There is no approved treatment for Sudan virus disease or Bundibugyo virus disease.
• Prevention:
  • Avoid Direct Contact: People should avoid contact with infected persons, body fluids, contaminated objects, and infected wild animals.
  • Isolation and Monitoring: Confirmed cases should be isolated immediately, while contacts should be monitored for 21 days.

About Public Health Emergency of International Concern (PHEIC)

• PHEIC is the highest level of health alert issued by the World Health Organization under the International Health Regulations (IHR).
• Governed by: PHEIC is governed under the International Health Regulations (IHR), 2005, which is a binding international legal agreement involving 196 countries.
• Criteria for Declaring a PHEIC:
  • Unusual or Unexpected Event: An outbreak qualifies as a PHEIC when the event is serious, sudden, unusual, or unexpected.
  • Risk of International Spread: The disease must have the potential to spread internationally and affect other countries.
  • Need for Immediate International Action: The crisis may require urgent and coordinated international response to control the spread of disease.
  • Scope Beyond Infections: A PHEIC is not strictly limited to viral or bacterial contagions.
    •  It can be triggered by critical exposure to chemical agents or radioactive materials.