Ebola virus disease
Ebola hemorrhagic fever is a severe and often deadly illness (death rate up to 90%) caused by the Ebola virus. Although the origin of the virus is not known, fruit bats are considered the likely host. It may be transmitted through contact with infected bodily fluids and contaminated surfaces. Common symptoms of the disease include: fever, chills, skin rash, malaise, weakness, muscle pain, vomiting and diarrhea, among others. Travelers to endemic regions, close contacts of patients with the disease and healthcare workers are at highest risk, particularly if they do not observe advised protective measures. You should search medical attention whenever you feel the described symptoms or think you have had contact with the virus. Infection with the virus must be confirmed by laboratory tests. There is no treatment for Ebola hemorrhagic fever besides supportive care, oral and intravenous fluids with electrolytes and possibly blood and/or platelet transfusions. The WHO elaborates protective measures for common citizens and healthcare workers, as well as directions in cases of outbreak.
What causes Ebola? Ebola hemorrhagic fever (Ebola fever) is caused by a virus belonging to the family called Filoviridae. Scientists have identified four types of the Ebola virus. Three have been reported to cause disease in humans: Ebola-Zaire virus, Ebola-Sudan virus, and Ebola-Ivory Coast virus. The human disease has so far been limited to parts of Africa. A very small number of people in the United States, who were infected with the fourth type of the virus, known as Ebola Reston, did not develop any signs of disease. The disease can be passed to humans from infected animals and animal materials. Ebola can also be spread between humans, by close contact with infected bodily fluids, or through infected needles at the hospital. A person infected with Ebola is contagious from the moment he/she begins to show symptoms.
How does Ebola cause infection? Ebola virus is able to infect someone by the following mechanism:
Ebola is introduced into the human population through close contact with the blood, secretions, organs or other bodily fluids of infected animals. In Africa, infection has occurred through the handling of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead in the rainforest. It is important to reduce contact with high-risk animals, including not picking up dead animals, found lying in the forest or handling their raw meat. Once a person comes into contact with an animal that has Ebola, it can spread within the community from human to human. Infection occurs from direct contact (through broken skin or mucous membranes with the blood, or other bodily fluids or secretions (stool, urine, saliva, semen) of infected people. Infection can also occur if broken skin or mucous membranes of a healthy person come into contact with environments that have become contaminated with an Ebola patient’s infectious fluids, such as soiled clothing, bed linen, or used needles. People are infectious, as long as their blood and secretions contain the virus. For this reason, infected patients receive close monitoring from medical professionals and receive laboratory tests to ensure the virus is no longer circulating in their systems before they return home. When the medical professionals determine it is okay for the patient to return home, they are no longer infectious and cannot infect anyone else in their communities.
What are the symptoms of Ebola? During the incubation period, which can last from 2 to 21 days, symptoms may include:
- Sudden onset of fever
- Chills
- Malaise
- Severe weakness
- Muscle pain
- Low back pain
- Headache
- Arthritis
- Sore throat
- Vomiting
- Diarrhea
- Nausea
- Skin rash
Late symptoms include:
- Impaired kidney function
- Impaired liver function
- Internal and external bleeding, commonly:
- Bleeding from eyes, ears, and nose
- Bleeding from the mouth and rectum (gastrointestinal bleeding)
- Depression
- Eye inflammation (conjunctivitis)
- Genital swelling (labia and scrotum)
- Increased feeling of pain in skin
- Rash over the entire body, often containing blood (hemorrhagic)
- Roof of mouth looks red
- Seizures, coma, delirium
As many as 90% of patients die from the disease. Patients usually die from shock rather than from blood loss.
Who is at highest risk? Persons at an increased risk for Ebola include:
- Travelers to an area of the world where Ebola occurs frequently (such as Central Africa)
- Hospital staff/caregivers for patients with Ebola
- Family members or close contacts of infected people
- People who have close contact with the body of a deceased person, infected with ebola virus, during burial ceremonies
- Hunters in rain forests who contact with abandoned dead animals
Research is being conducted to evaluate the risk of immunocompromised people or those with underlying diseases, to contacting the Ebola virus
When to seek urgent medical care? A person should seek urgent medical care when:
- Has traveled to Africa
- Has been in an area known to have Ebola virus disease
- Has been in contact with another person who is known or suspected to have Ebola and is beginning to show symptoms
- Has been exposed to Ebola fever
- Develops symptoms of the disorder
Urgent medical care is fundamental to improve the survival rateand to control the spread of the disease. Early diagnosis and treatment may improve the chances of survival.
Diagnosis There may be signs and symptoms of:
- Coma
- Disseminated intravascular coagulation
- Shock
Ebola virus infection can only be identified through laboratory testing. Tests used to diagnose Ebola fever include:
- Blood tests (CBC), commonly showing:
- Low white blood cell count
- Low platelet count
- Elevated liver enzymes
- Electrolytes
- Tests of how well the blood will clot (coagulation studies)
- Tests to identify infection by the virus
Treatment options Currently there is no specific treatment for Ebola fever, since current antiviral drugs do not work on the Ebola virus. Some patients will recover with the appropriate medical care. The patient is usually hospitalized and will most likely need intensive care. For patients with the disease, the available supportive care measures include:
- Oral rehydration and/or intravenous fluids, with solutions containing electrolytes, for dehydrated patients
- Bleeding problems may require transfusions of fresh blood and/or platelets
To avoid the spread of the disease, patients who are suspected of being infected, or those who have the confirmed diagnosis, should be isolated and treated by healthcare practitioners, under strict infection control precautions.
The WHO strongly recommends that people seek credible health advice about Ebola virus disease from their public health authority.
What to expect (Outlook/Prognosis)? As many as 90% of patients die from the disease. Patients usually die from shock rather than blood loss.
Possible complications Survivors may have hair loss and sensory changes.
Prevention Communities Currently there is no approved vaccine to prevent disease by Ebola virus. The only way to prevent infection and reduce the number of deaths, is by being aware of the risk factors and following protective measures for individual safety, which include:
- Follow directions issued by your country's Ministry of Health
- Animal meat should be thoroughly cooked before eating
- Reduce contact with high risk animals in rainforest areas, such as
- Fruit bats
- Monkeys
- Apes
- Avoid handling infected animals or carcasses. If you suspect an animal is infected, do not touch it
- Wash hands with soap and water frequently, particularly when visiting patients at hospitals or caring for someone at home. Do so specially after touching a patient, bodily fluids or patient's personal items and surroundings
- Avoid areas in which there are epidemics
- Avoid direct contact with the bodily fluids of ill persons, either through unsafe case management or unsafe burial practices
- Wear a gown, gloves, and mask around sick patients
- Protective measures at healthcare facilities, social gatherings and at home
- In case of suspicion of someone infected by Ebola virus in your community, encourage and support them to seek medical attention
- If you want to care for a person with the disease in your home, notify public health officials of your intention, in order for them to provide adequate training, protective equipment and instructions to care for the patient and protect yourself, your family and to properly dispose of the used materials
- Deceased persons, who died from Ebola virus infection should be handled with appropriate equipment and buried immediately
- Men who have recovered from the illness, can still spread the virus to their partner through their semen for up to 7 weeks after recovery. For this reason, it is important for men to avoid sexual intercourse for at least 7 weeks after recovery or to wear condoms if having sexual intercourse during 7 weeks after recovery.
Health Care Workers Healthcare workers treating patients with suspected or confirmed illness are at higher risk of infection than other groups.
In addition to standard healthcare precautions, healthcare workers should apply rigorous recommended infection control measures to avoid exposure to infected blood, fluids, or contaminated environments or objects, such as the patient’s soiled linens or used needles. Additionally they should:
- Use personal protection equipment such as individual gowns, gloves, masks and goggles or face shields
- Not reuse protective equipment or clothing unless they have been properly disinfected
- Change gloves between caring for each patient suspected of having Ebola
- Carry out invasive procedures, that can expose medical doctors, nurses and others to infection, under strict and safe conditions
In case of an outbreak
During an Ebola outbreak, the affected country’s public health authority reports its disease case numbers and deaths. Case numbers reflect both:
- Suspected cases of Ebola
- Laboratory-confirmed cases of Ebola
Sometimes numbers of suspected and confirmed cases are reported together. Sometimes they are reported separately.
Thus, numbers can shift between suspected and confirmed cases.
Analyzing case data trends, over time, and with additional information, is generally more helpful to assess the public health situation and determine the appropriate response.
WHO Measures for Protection The World Health Organization (WHO) provides technical advice to countries and communities to prepare for and respond to Ebola outbreaks.
WHO actions include:
- Disease surveillance and information-sharing across regions to watch for outbreaks
- Technical assistance to investigate and contain health threats when they occur, such as on-site help to identify sick people and track disease patterns
- Advice on prevention and treatment options
- Deployments of experts and the distribution of health supplies, such as personal protection gear for health workers, when requested by the country
- Communications to raise awareness of the nature of the disease and protective health measures to control transmission of the virus
- Activation of regional and global networks of experts to provide assistance, if requested, and mitigate potential international health effects and disruptions of travel and trade
Travel
During an outbreak, the WHO reviews the public health situation regularly, and recommends any travel or trade restrictions if necessary.
The risk of infection for travelers is very low since person-to-person transmission results from direct contact with the body fluids or secretions of an infected patient.
The WHO’s general travel advices include:
- Travelers should avoid all contacts with infected patients
- Health workers traveling to affected areas should strictly follow WHO-recommended infection control guidance
- Anyone who has stayed in areas where cases were recently reported, should be aware of the symptoms of infection, and seek medical attention at the first sign of illness
- Clinicians caring for travelers returning from affected areas, with compatible symptoms are advised to consider the possibility of Ebola virus disease
