Ebola Virus Disease

Ebola virus disease (EVD), Ebola hemorrhagic fever (EHF) or simply Ebola is a disease of humans and other mammals caused by an ebolavirus.

Symptoms start two days to three weeks after contracting the virus, with a fever, sore throat, muscle pain and headaches. Typically, vomiting, diarrhea and rash follow, along with decreased function of the liver and kidneys. Around this time, affected people may begin to bleed both within the body and externally. Death, if it occurs, is typically 6 to 16 days from the start of symptoms and is often due to low blood pressure due to fluid loss.

  • Ebola is a Filovirus which has five subspecies- three of them have high mortality rates for humans.
  • It is highly sensitive to heat, chemical disinfectants and exposure to UV and easy to kill

How does it spread?

  • It is transmitted in the first instance from non-human primates such as bats, to humans who come into close contact with them in the bush when these are caught for food. Thereafter transmission occurs from person to person via blood and body fluids in healthcare facilities and at home.
  • The infecting dose of EVD is very low- approximately 10 viral particles it is reported- which is why it is highly contagious.
  • Poor understanding and application of IPC such as frequent hand hygiene, proper protective equipment and good standard precautions are major factors in transmission.

[nggtags gallery=ebola-life template=caption]Human-to-human transmission occurs only via direct contact with blood or body fluid from an infected person (including embalming of an infected dead body), or by contact with objects contaminated by the virus, particularly needles and syringes. Other body fluids that may transmit ebolaviruses include saliva, mucus, vomit, feces, sweat, tears, breast milk, urine, and semen. Entry points include the nose, mouth, eyes, or open wounds, cuts and abrasions. Transmission from other animals to humans occurs only via contact with, or consumption of, an infected mammal, such as a fruit bat, or ape. The potential for widespread EVD infections in countries with medical systems capable of observing the correct medical isolation procedures where needed is considered low as the disease is only spread by direct contact with the secretions from someone who is showing signs of infection.

A person’s ability to spread the disease is often limited as the individual is often too sick to travel during the infectious stages of the disease. As transmission via air is generally ruled out, the possibility of transmission between non-seat-mate airline passengers is also generally ruled out. Because dead bodies are still infectious, traditional burial rituals may spread the disease. Nearly two thirds of the cases of Ebola infections in Guinea during the 2014 outbreak are believed to have been contracted via unprotected (or unsuitably protected) contact with infected corpses during certain Guinean burial rituals. Semen may be infectious in survivors for up to 7 weeks. It is not entirely clear how an outbreak is initially started. The initial infection is believed to occur after an ebolavirus is transmitted to a human by contact with an infected animal’s body fluids.

One of the primary reasons for spread is that the health systems function poorly in Africa where the disease mostly occurs. Medical workers who do not wear appropriate protective clothing may contract the disease. Hospital-acquired transmission has occurred due to the reuse of needles or lack of body substance isolation. Some healthcare centers caring for people with the disease do not have running water.

Airborne transmission has not been documented during EVD outbreaks. They are, however, infectious in rhesus monkeys as breathable 0.8–1.2 μm laboratory-generated droplets.

Signs and symptoms

[nggtags gallery=ebola-symptoms template=caption]Signs and symptoms of Ebola virus disease (EVD) usually begin suddenly with an influenza-like stage characterized by fatigue, fever, headaches, and pain in the joints, muscles, and abdomen. Vomiting, diarrhea, and loss of appetite are also common. Less common symptoms include sore throat, chest pain, hiccups, shortness of breath, and trouble swallowing. The average time between contracting the infection and the start of symptoms (incubation period) is 8 to 10 days, but it can vary between 2 and 21 days. In about 5-50% of cases, skin manifestations may include a maculopapular rash (a flat, area on the skin that can be red in white skinned people covered with small joined bumps). Early symptoms of EVD may be similar to those of malaria, dengue fever, or other tropical fevers, before the disease progresses to the bleeding phase.

In 40–50% of cases, bleeding from puncture sites and mucous membranes (e.g., gastrointestinal tract, nose, vagina, and gums) has been reported. In the bleeding phase, which typically begins five to seven days after first symptoms, internal and subcutaneous bleeding may present itself in the form of reddened eyes and bloody vomit. Bleeding into the skin may create petechiae, purpura, ecchymoses, and hematomas (especially around needle injection sites). Sufferers may cough up blood, vomit it, or excrete it in their stool.

Changes on laboratory tests as a result of Ebola virus disease include a low platelet count in the blood, an initially decreased white blood cell count followed by an increase in the white blood cell count, elevated levels of the liver enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and abnormalities in clotting often consistent with disseminated intravascular coagulation (DIC) such as a prolonged prothrombin time, partial thromboplastin time, and bleeding time. Heavy bleeding is rare and is usually confined to the gastrointestinal tract. In general, the development of bleeding symptoms often indicates a worse prognosis and this blood loss can result in death. All people infected show some signs of circulatory system involvement, including impaired blood clotting. If the infected person does not recover, death due to multiple organ dysfunction syndrome occurs within 7 to 16 days (usually between days 8 and 9) after first symptoms.


Infection control

The Ebola virus is only transmitted via direct contact with the bodily fluids of an infected mammal. Risk of transmission does not end with a person’s death, and thus it is recommended that the bodies of people who have died from Ebola be buried or cremated only with proper care.

The risk of transmission is increased amongst Ebola caregivers. Recommended measures when caring for people infected with Ebola include barrier-isolation, sterilizing equipment and surfaces, and wearing protective clothing including masks, gloves, gowns, and goggles. If a person with Ebola dies, direct contact with the body of the deceased patient should be avoided. The care of those individuals who have become infected with Ebola must be administered while carefully observing a very high-level of barrier-separation from the person infected, along with various certain cleaning and disinfection techniques. Education of those who provide care in these techniques, and the provision of the such barrier-separation supplies has been a priority of the Doctors Without Borders organization. Successfully addressing one of the “biggest danger(s) of infection” faced by medical staff requires their learning how to properly suit-up with personal protective equipment and to remove it afterwards. In Sierra Leone, the typical training period for the use of such safety equipment lasts approximately 12 days.

One step recommended by the World Health Organization is the education of the general public of the risk factors for Ebola infection and of the protective measures individuals can take. These include avoiding direct contact with infected people and regular hand washing using soap and water. Bushmeat, an important source of protein in the diet of some Africans, should be handled with appropriate protective clothing and thoroughly cooked before consumption. Some research suggests that an outbreak in the wild animals used for consumption may result in a corresponding human outbreak. Since 2003, such outbreaks have been monitored through surveillance of animal populations with the aim of predicting and preventing Ebola outbreaks in humans.

Older burial rituals, which might have included making any kind of direct contact with a corpse, require reformulation such that they consistently maintain a proper protective barrier between the corpse and the living. Social anthropologists may help find alternatives to traditional rules for burials.[80] Airline crews are instructed to follow a certain isolation procedure should anyone exhibit symptoms resembling the Ebola virus disease.

Ebolaviruses can be eliminated with heat (heating for 30 to 60 minutes at 60 °C or boiling for 5 minutes). On surfaces, some lipid solvents such as some alcohol-based products, detergents, sodium hypochlorite (bleach) or calcium hypochlorite (bleaching powder), and other suitable disinfectants at appropriate concentrations can be used as disinfectants.

In laboratories where diagnostic testing is carried out, biosafety level 4-equivalent containment is required, since ebolaviruses are World Health Organization Risk Group 4 pathogens. Laboratory researchers must be properly trained in BSL-4 practices and wear proper personal protective equipment.


Quarantine, also known as enforced isolation, is usually effective in decreasing spread. Governments often quarantine areas where the disease is occurring or individuals who may be infected. During the 2014 outbreak, Liberia closed schools.

Contact tracing

Contact tracing is regarded as important to contain an outbreak. It involves finding everyone who had close contact with infected individuals and watching for signs of illness for 21 days. If any of these contacts comes down with the disease, they should be isolated, tested, and treated. Then repeat the process by tracing the contacts’ contacts.

Further reading


Under the auspices of the ISC, the newly formed Infection Control Working Group (under the table leadership of Andreas Voss) has put together an Ebola preparedness questionnaire which was produced by the Infection Control Association of Singapore ; there has been active input by ICAN  as well. Please read the attached letter, and go to the link provided, to complete the questionnaire- it will take no more than 10 minutes of your time and will give us vital information to help with containment of the EVD epidemic

Please return by the 30th October so that the African site evaluations may be available for the ICAN conference.

Letter from ISC Infection Control Working Group
Link questionnaire: https://nl.surveymonkey.com/r/2XG8LV6

Thank you so much for your cooperation.



NIFCD: Poliomyelitis Research Foundation Public Lecture: EBOLA: Is it a global treat? 2014 JGlecture-flyer

WHO IPC Guidelines:

Who guideline on hand hygiene in health care in the Context of Filovirus Disease Outbreak Response Guideline_handhygiene_14112014 REV BA APP FINAL

New guidelines on Safely Burying Ebola Victims  http://www.nytimes.com/2014/11/08/world/europe/new-guidelines-for-burying-ebola-victims.html?_r=1

roadmapsitrep22Oct2014_eng (1)



Steps to put on personal protective equipment: http://www.who.int/entity/csr/disease/ebola/put_on_ppequipment.pdf

Steps to remove personal protective equipment: http://www.who.int/entity/csr/disease/ebola/remove_ppequipment.pdf

‘Stop EBOLA’ Free mobile application: http://ezcollab.who.int/_/ychmf2yv

CDC Information for Healthcare Workers and Settings:

21 October:

CDC: Interim Guidance for Environmental Infection Control in Hospitals for Ebola Virus


CDC:  Guidance on Personal Protective Equipment To Be Used by Healthcare Workers During Management of Patients with Ebola Virus Disease in U.S. Hospitals, Including Procedures for Putting On (Donning) and Removing (Doffing)


CDC: Ebola Medical Waste Management


CDC: Guidance on Air Medical Transport for Patients with Ebola Virus Disease


CDC: Interim Guidance for Monitoring and Movement of Persons with Ebola Virus Disease Exposure


CDC: Guidance for Safe Handling of Human Remains of Ebola Patients in U. S. Hospitals and Mortuaries


University of Nebraska Medical Centre – Viral Hemorrhagic Fever – Donning & Doffing PPE (posters)




**Infection Control Posters for the African Health Care Setting:


**CDC Resources for non-U.S. Healthcare Settings:


Sequence for Donning and Removing PPE:



IPAC Canada Ebolavirus Information and Resources:


Public Health Ontario IPAC Measures:


Ebola Readiness Checklist

Ebola readiness Checklist DRAFT (3)

Ebola KEY Messages

key msgs

A report of preliminary study, observations – published in The Lancet Infectious Disease: http://www.thelancet.com/journals/laninf/article/PIIS1473-3099%2814%2970954-5/fulltext

Donning and Doffing of PPEs When Handling Cases of Ebola Virus Disease—The Research Institute for Tropical Medicine

Decision Guide on Selection of Personal Protective Equipment for Ebola Virus Disease – Isolation Gowns or Suits – Public Health Ontario
Link: http://www.publichealthontario.ca/en/eRepository/EVD_PPE_Decision_Guide.pdf

Environmental Sanitation Practices to Control the Spread of Communicable Disease in Passenger Conveyances and Terminals – Public Health Agency of Canada
Link: http://www.phac-aspc.gc.ca/id-mi/inf-cont-inf/sanitation-hygiene-eng.php

Rapid Communications
Transmission dynamics and control of Ebola virus disease outbreak in Nigeria

BioMed Central and Springer EBOLA articles:  http://www.springer.com/biomed/virology/spotlight+on+ebola?SGWID=0-1771314-0-0-0&wt_mc=Banner.3rd%20party%20website%20banner.2.CON417.bmcnewsletter