Ebola Virus Outbreak- Preventive Measures
About the virus
Ebola virus, a member of the family Filoviridae, causes an acute systemic febrile illness associated with high mortality.
Structurally, the virus appears as an 80-100 nanometer elongated filamentous particle, with surface projections or peplomers. Every single virus particle or virion contains a copy of linear, negative-sense, single-stranded RNA with a helical nucleocapsid and a lipid envelope derived from the host cell plasma membrane.
The virus is stable and remains infectious for prolonged periods at room temperature. It can be destroyed by heat (60-degree celsius, 30 min) and lipid solvents.
It is a Biosafety-Level 4 Pathogen and requires maximum biological containment facilities.
Preventive Measures To Check The Ebola Epidemic
- Ebola virus disease, formerly called as Ebola Haemorrhagic Fever, is a severe, often fatal illness in humans.
- Ebola virus disease outbreaks occur primarily in remote villages of Central and West Africa, near tropical rainforests.
- The virus is transmitted to people from wild animals and spreads in the human population through human to human transmission.
- Fruit bats of the family Pteropodidae are considered to be the natural hosts of Ebola virus.
- Severely ill patients require intensive supportive care. No licensed specific treatment or vaccine is available for use in people or animals.
- Avoid travelling to areas of known outbreak. Find out about current epidemics by checking the CDC website.
- Wash your hands frequently with soap and water or an alcohol-based hand rub containing at least 60% alcohol, to avoid contracting infections of any sort.
- Avoid bush meat. If you are in an area of suspected outbreak, avoid buying or eating meat sold in local markets.
- Avoid contact with infected people, who are most infectious in the later stages of the disease.
- Follow infection control procedure (Barrier Nursing). If you are a healthcare worker, wear protective clothing such as gloves, masks, gowns and eye shields.
- Isolate the infected people. Dispose used needles and sterilize other instruments.
The recent Ebola outbreak
Since February this year (2014), Ebola virus disease cases have been appearing simultaneously in three different countries of West Africa- Sierra Leone (Freetown); Liberia (Monrovia); Guinea (Conakry); and now in Nigeria also.
Two US missionaries Dr Kent Brantly and Ms Nancy Writebol were detected of Ebola infection and airlifted from Liberia to a specialist isolation unit in Atlanta, for treatment.
Cross continent air travel, the rapid spread of disease and lack of any specific treatment or vaccines, is the major cause of concern about this disease.
Ebola first appeared in 1976 in two simultaneous outbreaks in Sudan and Democratic republic of Congo. The latter was in a village situated near the Ebola river, from which this disease got its name.
Ebola virus has 5 subtypes, named after the places from where they were isolated.
1. Bundibugyo Ebola Virus.
2. Zaire Ebola Virus.
3. Sudan Ebola Virus.
4. Reston Ebola Virus.
5. Tai Forest Ebola Virus.
The strain from the current epidemic, known as the "Zaire Strain" is the deadliest.
Microscopic View of Ebola Virus
Transmission of Virus
Ebola is primarily a zoonotic disease, with animals being the natural reservoirs of the virus. Handling of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelopes and porcupines, found ill or dead in the rain forests can spread the infection to humans.
It spreads in the community through human to human transmission, with infection resulting from direct contact (through broken skin or mucous membranes) with the blood, body secretions, organs or other bodily fluids of infected people, and indirect contact with the environment contaminated with such fluids. You can contract the disease if the infected person sneezes on you, that is, you are in immediate proximity, and also if you get in touch with the patients sweat, who is perspiring profusely.
Who are at risk, and how to suspect them being infected?
- Travelers to Africa, especially tourists to certain caves in Central Africa and underground mine workers can contract the infection from waste products and excreta of animals.
- Scientists conducting research on animals.
- People butchering or eating infected animals.
- Family members or contacts of patients.
- Medical and health care personnel while treating patients with Ebola virus disease. This occurs through close contact with patients when infection controlling practices are not strictly followed.
- There is no evidence to show spread by insect bites.
- Ebola virus is "pantropic", with viral replication taking place in almost all the organs.
- Initial symptoms are non-specific and include fever, intense weakness, muscle pain, headache and sore throat. This is followed by vomiting, diarrhea, impaired kidney and liver functions.
- The most reliable feature is the appearance of a non-itchy maculopapular rash, that begins on the face and neck and spreads centrifugally to the extremities.
- In severely ill patients, chest pain, cough, gastric upset, bleeding from eyes and other orifices, bruising and internal bleeding can occur.
- Worst complications being sepsis and multi-organ failure.
Prevention and Control
There is no licensed vaccine to prevent Ebola virus disease. Severely ill patients are often dehydrated and require intensive care and IV fluids. There being no specific treatment available, strict quarantine procedures and barrier nursing are the only means to contain an outbreak.
- Educational public health messages raising awareness of the risk factors and protective measures an individual can follow are the only ways to reduce human infection.
- To reduce the risk of wildlife to human transmission, people should avoid contact with infected fruit bats, monkeys, and apes and abstain from eating their meat. Animal products should be thoroughly cooked before consumption. Those handling such animals should wear gloves and appropriate protective clothing.
- Isolated patient placement in single-patient rooms with private bathrooms is essential. Close physical contact with Ebola patients should be avoided. Gloves, gown (fluid resistant or impermeable), eye protection and face masks should be worn by relatives taking care of ill patients at home.
- Regular frequent hand washing with soap and water after visiting the patients is essential.
- Health care workers should follow standard precautions with all patients regardless of their diagnosis, which include basic hand hygiene, respiratory hygiene, personal protective equipment and safe injection practice.
- Health care personnel dealing with suspected or confirmed Ebola cases should apply other additional infection control measures to avoid any exposure to patient's blood and body fluids. When in close contact, within a meter, of a patient, health personnel should wear face protection (a face shield or a medical mask and goggles), a clean, nonsterile long sleeved gown and gloves.
- The use of needles and other sharps should be as limited as possible.
- Health care workers should avoid Aerosol-Generating Procedures (Bilevel Positive Air Pressure, Bronchoscopy, sputum induction and open suction of airways) for Ebola patients.
- Health workers with accidental Percutaneous or mucocutaneous exposure to blood, body fluids, secretions or excretions of Ebola patients should stop working and immediately wash the affected skin surface with soap and water. Mucous membranes (like conjunctiva) should be irrigated with copious amounts of water or eye wash solution. They should immediately contact occupational health supervisor for assessment and access to post-exposure management.
- Samples taken from suspected human or animal Ebola cases for diagnosis should be handled by trained staff and processed in suitably equipped labs.
Sequelae during recovery
Recovery is slow. It may take months to regain weight and strength, and the virus may remain in the body for weeks. The late complications include the following:
- Hair loss
- Sensory changes
Diagnostic tests to detect the virus
- Antibody capture ELISA
- Antigen detection tests
- Serum neutralization test
- Reverse transcriptase PCR assay
- Electron microscopy
- Virus isolation by cell culture
Samples from patients are an extreme bio hazard risk; testing should be conducted under maximum virological containment conditions.
Additional protective measures
Health care personnel, when handling copious amounts of blood, other body fluids, vomit or feces, should follow additional preventive measures, that include-
- Double gloving.
- Disposable shoe covers.
- Leg coverings to avoid any contact with infected secretions.
Measures to prevent spread of Ebola virus
Family of Patients
Health care Personnel
Avoid affected areas
Avoid close contact with patient
Strict quarantine of suspects
Avoid bush meat
Wear gloves and eye shields
Wash hands frequently
Do not handle patient's secretions
Limit use of sharps
Treating Ebola Victims
A new serum raises hope for cure
An experimental serum known as "ZMab", which had only been previously tested on monkeys, is a ray of hope to bring a cure to the dangerous virus. "ZMab" is one of the new class of drugs called "the monoclonal antibodies", that use uniquely manufactured proteins to prevent the Ebola virus from infecting new cells. This class of drugs has also been used successfully to treat certain cancers.