Ebola Virus Disease (EVD)
Science & Technology
- PYQs10
- Articles2
Background
Ebola Virus Disease (EVD), formerly known as Ebola hemorrhagic fever, is a rare but severe and often fatal illness in humans. It is caused by infection with one of the Ebola virus species, belonging to the family Filoviridae. Understanding EVD is critical for global health security, public health preparedness, and international cooperation in disease control, aligning with India's commitments to global health initiatives.
EVD outbreaks pose significant global health security threats, impacting public health, economies, and international travel. Understanding its epidemiology, prevention, and control measures is crucial for disaster management and international cooperation.
- Disease Type
- Viral Hemorrhagic Fever (VHF)
- Causative Agent
- Ebola virus (genus Ebolavirus, family Filoviridae)
- Natural Reservoir
- Fruit bats are considered the likely natural host
- First Identified
- 1976, near the Ebola River in the Democratic Republic of Congo (then Zaire)
Facts & tables
Ebola virus is transmitted to people from wild animals and spreads in the human population through direct contact with the blood, secretions, organs or other bodily fluids of infected people, and with surfaces and materials (e.g. bedding, clothing) contaminated with these fluids. Healthcare workers are at high risk if proper infection control measures are not followed. Burial ceremonies where mourners have direct contact with the body of the deceased can also play a significant role in transmission.
Symptoms of EVD typically appear 2 to 21 days after exposure to the virus. Initial symptoms include sudden onset of fever, fatigue, muscle pain, headache, and sore throat. These are followed by vomiting, diarrhea, rash, symptoms of impaired kidney and liver function, and in some cases, both internal and external bleeding (e.g., oozing from the gums, blood in the stools). Laboratory tests show low white blood cell and platelet counts and elevated liver enzymes.
- Fatality Rate
- Can be high, averaging around 50%, but varies significantly by outbreak and species.
- Incubation Period
- 2 to 21 days (average 8-10 days).
- Vaccine Availability
- Ervebo (rVSV-ZEBOV) vaccine approved for Zaire ebolavirus.
- Treatment
- Supportive care is primary; monoclonal antibody treatments (Inmazeb, Ebanga) are available for Zaire ebolavirus.
- Global Health Emergency
- WHO has declared Public Health Emergencies of International Concern (PHEIC) for EVD outbreaks multiple times.
- Zoonotic Origin
- Transmitted to humans from wild animals, then human-to-human.
- Causative Agent
- Ebola virus (a filovirus)
- Transmission
- Direct contact with blood, secretions, organs or other bodily fluids of infected people, and from contaminated surfaces and materials.
| Species Name | Geographic Origin | Fatality Rate (Approx.) |
|---|---|---|
| Zaire ebolavirus | Democratic Republic of Congo | 25-90% (average 50%) |
| Sudan ebolavirus | Sudan, Uganda | 40-100% (average 50%) |
| Bundibugyo ebolavirus | Uganda | 50% |
| Taï Forest ebolavirus | Côte d'Ivoire | Low (1 reported case, non-fatal) |
| Bombali ebolavirus | Sierra Leone | Unknown (detected in bats, human cases not confirmed) |
| Pathway | Description | Risk Level |
|---|---|---|
| Direct Contact | Contact with blood, bodily fluids (urine, feces, vomit, semen, breast milk) of infected persons or deceased. | High |
| Contaminated Objects | Contact with needles, syringes, bedding, clothing, or medical equipment contaminated with fluids. | High |
| Healthcare Settings | Lack of proper infection control (PPE, sterilization) among healthcare workers. | Very High |
| Burial Practices | Direct contact with the body of a deceased EVD patient during traditional burial rituals. | High |
| Animal-to-Human | Contact with infected fruit bats, chimpanzees, gorillas, monkeys, forest antelope, or porcupines (e.g., through hunting, butchering). | Moderate |
| Strategy | Key Actions |
|---|---|
| Surveillance & Response | Early detection, rapid diagnosis, contact tracing, isolation of cases, quarantine of contacts. |
| Infection Prevention & Control (IPC) | Use of Personal Protective Equipment (PPE), hand hygiene, safe injection practices, waste management in healthcare settings. |
| Community Engagement | Public awareness campaigns, risk communication, promoting safe burial practices, addressing cultural beliefs. |
| Vaccination | Targeted vaccination of healthcare workers, frontline responders, and contacts of confirmed cases during outbreaks. |
| Safe Burial Practices | Ensuring dignified and safe burials for EVD victims to prevent further transmission. |
| Type | Reference |
|---|---|
| Conceptual area | Microbiology & Epidemiology |
| Conceptual area | Welfare Schemes & Social Policies |
| Body | Role |
|---|---|
| World Health Organization (WHO) | Declares emergency |
| Centers for Disease Control and Prevention (CDC) | Implements travel ban |
| Ministry of Health and Family Welfare (India) | Coordinates national preparedness |
Prelims angle
For UPSC Prelims, questions on EVD typically focus on factual aspects: the type of virus (Filoviridae), its zoonotic reservoir (fruit bats), modes of transmission (direct contact with bodily fluids), key symptoms (hemorrhagic fever), the name of the approved vaccine (Ervebo), and the role of international organizations like WHO in declaring Public Health Emergencies of International Concern (PHEIC). Candidates should also be aware of the geographical regions most affected by outbreaks.
For UPSC Mains (GS2 - Health, GS3 - Science & Technology), EVD is relevant for questions on global health security, India's preparedness for emerging infectious diseases, international cooperation in disease control, ethical considerations during outbreaks (e.g., travel bans, quarantine), and the socio-economic impact of epidemics. Discussions might include the challenges of vaccine distribution, the role of public health infrastructure, and the importance of 'One Health' approach in preventing zoonotic spillover. India's experience in managing similar health crises and its contribution to global health initiatives are also important angles.
- Ebola is a severe, often fatal viral hemorrhagic fever.
- Transmitted through direct contact with bodily fluids of infected animals or humans.
- Outbreaks primarily occur in sub-Saharan Africa.
- WHO's declaration of a Public Health Emergency of International Concern (PHEIC) triggers global response.
- National preparedness includes surveillance, isolation, and border control measures.
| Year | Framing tags |
|---|---|
| 2025 | Multi-statement analysis, Conceptual understanding |
| 2025 | Statement-based questions, Conceptual understanding |
| 2022 | Multi-statement analysis, Conceptual understanding |
| 2021 | Factual recall, Conceptual understanding |
| 2021 | Statement-based questions, Factual recall |
| 2017 | Statement-based questions, Factual recall |
| 2015 | Factual recall |
| 2015 | Factual recall, Terminology-based question |
| 2013 | Factual recall, Multi-statement analysis |
| 2013 | Statement-based questions, Conceptual understanding |
Current affairs
Recent Ebola outbreaks in Africa have prompted the World Health Organization (WHO) to declare international emergencies, highlighting the ongoing threat and the need for robust global and national preparedness, including travel restrictions and enhanced surveillance.
The recurring nature of Ebola outbreaks, particularly in the Democratic Republic of Congo and other African nations, underscores the persistent challenge EVD poses to global health security. The WHO's declaration of a Public Health Emergency of International Concern (PHEIC) during significant outbreaks mobilizes international resources and coordination, emphasizing the need for rapid response, vaccine deployment, and robust public health measures.
Timeline
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Microbiology & Epidemiology
Conceptual area
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Welfare Schemes & Social Policies
Conceptual area
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Prelims 2013
Factual recall, Multi-statement analysis
-
Prelims 2013
Statement-based questions, Conceptual understanding
-
Prelims 2015
Factual recall
-
Prelims 2015
Factual recall, Terminology-based question
-
Prelims 2017
Statement-based questions, Factual recall
-
Prelims 2021
Factual recall, Conceptual understanding
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Prelims 2021
Statement-based questions, Factual recall
-
Prelims 2022
Multi-statement analysis, Conceptual understanding
-
Prelims 2025
Multi-statement analysis, Conceptual understanding
-
Prelims 2025
Statement-based questions, Conceptual understanding
-
U.S. extends Ebola travel ban to Green Card holders
Ebola is a severe, often fatal viral hemorrhagic fever. The article highlights an outbreak in Africa, WHO's declaration of an international emergency, and national preparedness efforts in India and the US.
-
Canada imposes Ebola-related travel ban, Bahamas to increase screening
Ebola Virus Disease is a highly contagious and often fatal viral illness, transmitted from animals to humans and then human-to-human. It causes severe symptoms including hemorrhage and has a high fatality rate, necessitating robust public health responses.
See also
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Past papers
2013–2025 · 10 questions
In the news
U.S. extends Ebola travel ban to Green Card holders
Ebola is a severe, often fatal viral hemorrhagic fever. The article highlights an outbreak in Africa, WHO's declaration of an international emergency, and national preparedness efforts in India and the US.
Canada imposes Ebola-related travel ban, Bahamas to increase screening
Ebola Virus Disease is a highly contagious and often fatal viral illness, transmitted from animals to humans and then human-to-human. It causes severe symptoms including hemorrhage and has a high fatality rate, necessitating robust public health responses.
Try these PYQs
With reference to monoclonal antibodies, often mentioned in news, consider the following statements:
I. They are man-made proteins.
II. They stimulate immunological function due to their ability to bind to specific antigens.
III. They are used in treating viral infections like that of Nipah virus.
Which of the statements given above are correct?
Monoclonal antibodies are lab-made proteins that target specific antigens and can be used to treat viral infections like Nipah virus. * ✅ I. Man-made proteins – Created by cloning a single immune cell type. * ✅II. Bind to specific antigens – Help stimulate or guide immune response. * ✅III. Used in viral infections – Applied in treating infections like Nipah virus. All three statements are correct.
Among the following which was frequently mentioned in the news for the outbreak of the Ebola virus recently?
Guinea, Sierra Leone, and Liberia were in the news for the outbreak of the Ebola virus. The most widespread outbreak of the Ebola virus disease began in 2013 and continued until 2016, causing major loss of life and socio-economic disruption in the West African region, mainly in the countries of Guinea, Liberia, and Sierra Leone.
The first cases were recorded in Guinea in December 2013. Later, the disease spread to neighboring Liberia and Sierra Leone. Therefore, option B is the correct answer.
Consider the following statements:
1. In tropical regions, Zika virus disease is transmitted by the same mosquito that transmits dengue.
2. Sexual transmission of Zika virus disease is possible.
Which of the statements given above is/are correct?
Statement 1 is correct: The Zika virus is primarily transmitted by the Aedes aegypti mosquito, which is the same mosquito that transmits the dengue virus in tropical and subtropical regions. Statement 2 is correct: While Zika virus is primarily transmitted through mosquito bites, the virus can also be transmitted from person to person through sexual contact. Therefore, both the statements 1 and 2 are correct.
H1N1 virus is sometimes mentioned in the news with reference to which one of the following diseases?
Influenza (H1N1) virus is a subtype of influenza A virus that was the most common cause of human influenza (flu) in 2009 and is associated with the 1918 outbreak known as the Spanish Flu. It is an orthomyxovirus that contains the glycoproteins haemagglutinin and neuraminidase. For this reason, they are described as H1N1, H1N2 etc., depending on the type of H or N antigens they express with metabolic synergy. - Haemagglutinin causes red blood cells to clump together and binds the virus to the infected cell.
- Neuraminidase is a type of glycoside hydrolase enzyme which helps to move the virus particles through the infected cell and assist in budding from the host cells. In June 2009, the World Health Organization (WHO) declared the new strain of swine-origin H1N1 as a pandemic. This strain is often called swine flu by the public media.
Consider the following statements:
I. No virus can survive in ocean waters.
II. No virus can infect bacteria.
III. No virus can change the cellular transcriptional activity in host cells.
Which of the statements given above are correct?
Viruses can survive in oceans, infect bacteria, and alter host cell transcription. ❌Statement I: False. Viruses can survive in ocean waters, and marine viruses are highly abundant. ❌Statement II: False. Viruses can infect bacteria; for example, bacteriophages specifically infect bacteria. ❌Statement III: False. Viruses can alter host transcription and modify host gene expression. None of the statements are correct.
Show 5 more PYQs
Consider the following:
1. Bacteria
2. Fungi
3. Virus
Which of the above can be cultured in artificial/synthetic medium?
* Bacteria can be cultured and grown in various artificial culture media, such as nutrient broth, agar plates, or other specific media formulations. Bacteria can metabolize and utilize the nutrients provided in these synthetic culture media to grow and reproduce. * Fungi can also be cultured in artificial media, such as potato dextrose agar, Sabouraud dextrose agar, or other specialized fungal growth media. Fungi can utilize the organic compounds and nutrients present in these synthetic media to support their growth and development. * Viruses, on the other hand, are obligate intracellular parasites and cannot be directly cultured in artificial or synthetic media. Viruses require living host cells to replicate and propagate, as they lack the necessary machinery for autonomous growth and reproduction.
Consider the following statements in respect of probiotics
1. Probiotics are made of both bacteria and yeast.
2. The organisms in probiotics are found in foods we ingest but they do not naturally occur in our gut.
3. Probiotics help in the digestion of milk sugars.
Which of the statements given above is/are correct?
Statement 1 is correct. Probiotics can be made from both bacteria and yeast. Some common probiotic strains include bacteria like Lactobacillus and Bifidobacterium, and yeasts like Saccharomyces boulardii. Statement 2 is incorrect. The organisms in probiotics are naturally found in the human gut. We have a complex gut microbiome with trillions of bacteria and other microbes, some of which are beneficial. Probiotics are supposed to introduce specific strains of these beneficial microbes to improve gut health. Statement 3 is correct. Probiotics might help with lactose digestion, but it depends. Lactose intolerance is caused by a lack of the enzyme lactase, which breaks down lactose (milk sugar) in the gut. Some probiotic strains might produce lactase, potentially aiding digestion in lactose-intolerant individuals.
Which of the following statements is/are correct?
1. Viruses lack enzymes necessary for the generation of energy.
2. Viruses can be cultured in any synthetic medium.
3. Viruses are transmitted from one organism to another by biological vectors only.
Select the correct answer using the codes given below.
Statement 1 is correct: Viruses do not have metabolic machinery of their own. They lack enzymes needed for ATP generation and therefore must depend entirely on a host cell. Statement 2 is incorrect: Viruses cannot be grown on artificial or synthetic media. They need living host cells (bacteria, plants, animals, or cell cultures) to replicate. Statement 3 is incorrect: Transmission can occur through: - Physical contact, respiratory droplets - Contaminated water/food - Airborne routes - Fomites (inanimate objects) - Biological vectors (mosquitoes, ticks, etc.) Hence, vectors are not the only mode of transmission.
Which of the following diseases can be transmitted from one person to another through tattooing?
1. Chikungunya
2. Hepatitis B
3. HIV-AIDS
Select the correct answer using the codes given below.
* Chikungunya is a mosquito-borne viral disease that cannot be spread through tattooing. * Hepatitis B is a liver infection that can lead to liver failure and cancer. It's spread through contact with the blood, open sores, or body fluids of an infected person. * HIV is a virus that destroys the white blood cells responsible for fighting infections. It can result in AIDS, the final stage of infection. It spreads mainly through unprotected sex, sharing drug needles, or contact with infected blood.
Consider the following statements:
1. Adenoviruses have single-stranded DNA genomes whereas retroviruses have double-stranded DNA genomes.
2. Common cold is sometime caused by an adenovirus whereas AIDS is caused by a retrovirus.
Which of the statements given above is/are correct?
Statement 1 is incorrect: Adenoviruses have double-stranded DNA genomes. Retroviruses have single-stranded RNA genomes. Statement 2 is correct: Adenoviruses are one of the many viruses that can cause the common cold. AIDS (Acquired Immunodeficiency Syndrome) is caused by the Human Immunodeficiency Virus (HIV), which is a type of retrovirus.