1. What is Ebola hemorrhagic fever?
Ebola hemorrhagic fever is a serious and often fatal disease (hereafter referred to as Ebola) with a mortality rate of up to 90%. The disease can affect humans and other primates (monkeys, gorillas and chimpanzees).
Ebola was first detected in two simultaneous outbreaks in 1976, one in a village in the Democratic Republic of Congo near the Ebola River and the other in a remote area of Sudan.
The origin of the virus is not known. However, based on the available evidence, it is believed that fruit bats (family Foxbatidae) may be the natural host of Ebola virus.
2. How do people become infected with this virus?
Humans become infected with Ebola through close contact with the blood, secretions, organs or other body fluids of infected animals. In Africa, people have become infected by handling infected and sick or dead chimpanzees, gorillas, fruit bats, monkeys, forest antelopes, and porcupines in the rainforest. It is important to reduce contact with high-risk animals (i.e. fruit bats, monkeys or apes), including picking up dead animals found in the forest or handling their raw meat.
Once someone comes into contact with an animal infected with Ebola, it can cause human-to-human transmission in the community. Infection can occur when people come into direct contact with blood, body fluids or other secretions (feces, urine, saliva and sperm) of an infected person through broken skin or mucous membranes. Infection can also occur when a healthy person’s broken skin or mucous membranes come into contact with the environment or objects contaminated with blood and body fluids from an Ebola patient (e.g., soiled clothing, bed sheets, or used needles).
Medical personnel can be exposed to this virus if they do not wear appropriate personal protective equipment when treating Ebola patients. Health care workers at all levels of the health system (hospitals, clinics, and health posts) should be aware of the nature of the disease and how it is transmitted and strictly adhere to the recommended infection control precautions.
Direct contact between people and the dead body during the funeral of an Ebola victim is also an important mode of Ebola transmission. Therefore, people must wear protective clothing and gloves with strong protection when handling the bodies of Ebola deceased and burying the deceased immediately.
Ebola is contagious as long as the patient has Ebola in his or her blood and secretions. Therefore, an infected patient should be closely observed by health care workers and laboratory tests should be performed to ensure that the virus is no longer present in the patient’s body before discharge home. When the health care provider determines that the patient is ready to go home, the patient is no longer contagious and will not cause infection to anyone else in the community. Men may still transmit the virus to their sexual partners through their semen for up to 7 weeks after recovery. Therefore, men should avoid sexual intercourse for at least 7 weeks after recovery or wear a condom when having intercourse for 7 weeks after recovery.
3. Who is at the highest risk of infection?
In the event of an outbreak, the persons at higher risk of infection are
(1) Medical personnel.
(2) Family members or others who have had close contact with the patient.
(3) Persons who come into direct contact with the body of the deceased during the funeral process.
(4) People who have come into contact with dead animals in the forest in rainforest areas.
More research is needed to understand whether people with compromised immunity or other underlying diseases are more susceptible to the virus than others.
Exposure to the virus can be reduced by taking protective measures in clinics and hospitals, at community gatherings, or at home.
4. What are the typical signs and symptoms of Ebola virus infection?
Typical signs and symptoms include sudden onset of fever, extreme malaise, muscle pain, headache, and sore throat. This is followed by vomiting, diarrhea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding.
Clinical test results include decreased blood white blood cell count and platelet count and elevated liver enzymes.
The incubation period is 2-21 days. Patients are infectious once they begin to show symptoms. Patients are not contagious during the incubation period.
Ebola virus infection can only be confirmed by laboratory testing.
5. When should people seek medical attention?
People should seek immediate medical attention when they have been in an area where Ebola is known to exist or have been in contact with someone known or suspected to have Ebola and have begun to develop symptoms.
When a patient is suspected of having the disease, he or she should be reported immediately to the nearest health facility. Prompt medical attention is essential to improve the survival of the patient. Infection control procedures should also be initiated immediately to control the spread of the disease.
6. How is Ebola treated?
Severe patients require intensive supportive therapy. Patients often become dehydrated and require intravenous or oral rehydration for electrolyte replacement. There is no specific treatment available.
Some patients can recover with appropriate medical treatment.
To facilitate control of further transmission of the virus, suspected or confirmed cases should be isolated from other patients and treated by health workers who have taken strict infection precautions.
7. What can I do? Can the disease be prevented?
There is no approved vaccine for Ebola. There are several vaccines in clinical trials, but none are currently available for clinical use.
Raising awareness of risk factors and taking effective protective measures is the only way to reduce morbidity and mortality.
Methods to prevent infection and transmission
Although the initial Ebola cases were infected through handling of infected animals or their carcasses, sequel case infections are often caused by direct contact with case body fluids, or unsafe case management and burial operations. This outbreak is primarily caused by spread through human-to-human transmission. The following measures can help prevent infection and limit transmission.
(1) Knowledge of the nature of the disease, how it is transmitted, and how to prevent its further spread
(2) Follow the guidelines issued by the national health authorities
(3) Encourage and support people in the vicinity to seek medical treatment if they are suspected of having Ebola
(4) Wear appropriate protective equipment when dealing with Ebola fatalities
In addition, individuals should reduce contact with high-risk infected animals (e.g., fruit bats, monkeys, or apes) in affected tropical rainforest areas. If an animal is suspected to be infected, do not handle them again. Ensure that animal products (blood and meat) are cooked before they are consumed.
8. What is the situation of medical personnel? How do you protect yourself from the high risks associated with treating and caring for patients?
Medical personnel treating suspected or confirmed cases are at a higher risk of infection than the rest of the population.
(1) In addition to standard protective measures, health care workers should strictly follow recommended infection control measures to avoid contact with patients’ blood, body fluids, or Ebola-contaminated environments or objects (e.g., patients’ soiled bed sheets or used needles).
(2) Medical staff should have a thorough understanding of the disease and how to safely manage cases clinically.
(3) Personal protective equipment such as gowns, gloves, face shields, goggles, or protective masks should be used.
(4) Personal protective equipment should not be reused unless it has been properly disinfected.
(5) Gloves should be changed after each suspected case is seen and cared for.
(6) Invasive procedures make physicians, nurses, and others more susceptible to infection and should be performed under strict safety conditions.
(7) Ebola patients should be treated in isolation.
9. What do you think about rumors that certain foods can prevent or treat infections?
WHO strongly recommends that people should obtain reliable health advice on Ebola from public health authorities.
Since there are no specific drugs for Ebola, the best treatment is intensive supportive care provided by hospital health workers under strict infection control procedures. Further infections can be controlled according to recommended protective measures.
10. How can WHO protect health during an outbreak?
WHO provides technical advice to countries to prepare for and respond to the Ebola outbreak.
Actions taken by WHO include.
(1) Conduct disease surveillance, share information between regions, and monitor outbreak dynamics
(2) Provide technical support for investigation and outbreak control in the event of an outbreak – for example, assisting in case finding and tracking disease transmission patterns in the field
(3) Advise on prevention and treatment programs
(4) Dispatch experts and provide health supplies (e.g., personal protective equipment for health workers) as requested by the country concerned
(5) Enhance communication and raise awareness of the nature of the disease and protective measures to control the spread of the virus
(6) Activate regional and global networks of experts to provide support, upon request, to mitigate potential international health impacts and the impact on travel and trade
11. Why did the number of cases reported by health officials fluctuate during the outbreak?
In the event of an Ebola outbreak, public health authorities in the country where the outbreak occurs report the number of cases and deaths that occur. These numbers can change daily, and the number of cases includes both suspected and laboratory-confirmed cases, sometimes reporting suspected and confirmed cases together and sometimes reporting them separately. Therefore, changes may occur between the number of suspected and confirmed cases.
Analysis of trends in cases over time, along with additional information, is useful in assessing the public health situation and determining the appropriate response to be made.
12. Is it safe to travel during an outbreak and what are WHO’s travel recommendations?
During an outbreak, WHO regularly assesses the public health situation and makes recommendations for travel or trade restrictions as necessary.
Since interpersonal transmission of Ebola is caused by direct contact with body fluids or secretions from infected patients, the risk of infection for travelers is low.
WHO’s general travel recommendations.
(1) Travelers should avoid any contact with patients.
(2) Medical personnel traveling to affected areas should strictly adhere to WHO recommended infection control guidelines.
(3) Anyone who has spent time in an area where a recent case has been reported should be aware of the symptoms of the disease and seek medical attention at the first sign of illness.
(4) Clinicians providing consultation services to travelers returning from an infected area with associated symptoms should consider the possibility that the patient is infected with Ebola.
What are the conclusions of the WHO risk assessment of the current Ebola outbreak in West Africa?
High risk of transmission from countries in adjacent regions through cross-border travel
Moderate risk in slightly distant parts of Africa
Low risk of transmission in countries outside Africa
14. What are the conclusions of the WHO risk assessment for personal travel and transport?
Very low risk for travelers and business people returning from infected countries
Low risk for people visiting friends and relatives (unless in direct contact with patients/dead bodies/animals infected with Ebola)
Low risk of infection in people travelling with sick people on transport (but contact tracing is required)
Very low risk of infection for medical personnel working in the infected area if protection is provided according to basic medical protocols ~ low