Table of Contents
Replication
- Ebola virus don’t replicate through cell division due to their acellular nature.
- It uses a combination of virally encoded host enzyme with host cell structure to copy themselves.
- It then proceeds to self-assemble into viral micro molecular structure within the host cell.
- The virus initiates contact with the host cell by attacking host receptors through the glycoprotein surface.
- Pinocytosis virus penetrates the cell through fussing its membrane with vesicle membrane and this is a form of endocytosis.
- Viruses then can release nucleocapsid into the cytoplasm of the host cell.
- Negative sense single-strand RNA is used as a template for the synthesis of viral protein by the host cell’s ribosome.
- Once cell function is disrupted by the presence of the virus can dominate to produce more copies of itself.
- Then by budding the outer envelope of the virus is formed.
- This process destroys the host cell. (Microbewiki, 2015)
Symptoms
Early symptoms as:
- Fever: due to the binding of shedding proteins with macrophages and dendritic cells this binding leads to produce massive amounts of immune modulators from macrophages and cause fever.
- Muscular pain.
- Weakness.
- Chills.
The progress of symptoms may occur: • Headache.
- Loss of appetite.
- Vomiting.
- Bloody coughing.
- Red eyes.
- Abdominal pains.
- Rare neurologic symptoms.
- Severe watery diarrhea.
- Chest pain.
- Short breath.
- Brain edema (Fluid accumulate around and within the brain).
- Nausea.
- Hemorrhage in all body organs.
Diagnosis
- Right after infection diagnosis is difficult as early symptoms of Ebola virus disease like fever, headache, and weakness are not specific to the Ebola virus disease.
- To know if the patient has Ebola virus disease there must be symptoms and a possible exposure to the virus within 21 days. A possible exposure means:
- The patient may be contacted with blood or body fluids of an infected person with EVD.
- Ormaybecontactedwithcontaminatedobjectswithbloodorbodyfluidsofan infected person.
- Also, the Patient may be contacted with infected bats or apes.
Methods to detect EVD in blood:
- PCR to detect a few levels of the virus in the blood.
- Or detecting antibodies an EVD patient produces to the infection. (CDC, n.d.)
Transmission:
- Ebola virus is considered an emerging zoonotic disease that affects human and non- human primates.
- Ebola virus mainly transmitted from wild animals to humans which then spread and transmitted from human to human.
- Ebola virus isn’t an airborne virus.
- Ebola virus disease can infect humans through contact with infected animals (as chimpanzees, fruit bats).
- Ebola virus is nosocomial and transmitted from infected human to another human through direct contact with body fluids.
- Blood, feces, and vomit are considered to be the most infectious body fluids.
- Ebola virus also can be detected in milk, urine, and semen and at severe stages, it may be found in saliva.
- It was found that the Ebola virus is still present for almost 3 months in seminal fluid after the initial diagnosis.
- Ebola virus was found to be transmitted indirectly with contact of previous contaminated surfaces and objects.
- The direct contact with those who died by Ebola is also considered a high risk ‘ traditional funeral practice ‘.
- Ebola virus can survive on dry surfaces for several hours (e.g.: doorknobs), also can survive in body fluids for several hours (e.g.: blood).
- A person can be infectious only after the development of signs and symptoms.
- The incubation period of the Ebola virus was known to be 4 to 10 days but can be shorter (2 days) or longer (21 days).
- In Africa, Ebola has spread as a result of wild animals hunted for food and living in the wild places with direct contact with the animals. (World Health Organization, 2020)
Prevention &control
- Traveling to areas where Ebola is widespread must be avoided.
- By wearing masks, gloves, and goggles when come in contact with infected ones. If you are in areas where Ebola is present:
- Avoid contact with bats, monkeys, chimpanzees, and gorillas as these animals can infect people with Ebola.
- Avoid contact with blood and body fluids of infected ones (such as urine, feces, saliva, and vomit).
- Items of infected ones (as clothes, bedding, needles, and medical equipment) should be disposed of.
- Funeral or burial rituals that require handling the body of someone who died from EVD should be avoided.
Treatment
- Ebola virus treatment is limited to supportive treatment.
- Supportive therapy concerned with balancing the fluids and electrolytes of the patient and maintaining their blood pressure and oxygen status.
- Treatment of any complicating infections.
- Professionals of health care recommend isolating patients diagnosed with Ebola in special hospitals for treatment.
- There are some investigational therapies as the antiviral drug REMDESIVIR and some other drugs that use monoclonal antibodies, one of these drugs is ZMapp that is considered standard during Ebola outbreaks and has been used during Ebola epidemic in west Africa. Patients that received ZMapp was reported that mortality rate of 49% in comparison to patients that not receive any treatment reported mortality rate above 75%. (Molteni, 2020)
- A company called Regeneron Pharmaceuticals produced monoclonal antibody cocktail that had a big impact on lowering the mortality rate down to 29%, While NIAID’s monoclonal antibody mAb114 mortality rate 34% percent. (Molteni, 2020)
- A good result was reported for those who take treatments directly after infection as the virus titer was low (Molteni, 2020)
Vaccine
Ebola vaccine rVSV-ZEBOV (trade name “Ervebo”), which is a single dose vaccine regimen which found to be safe and protective against only the Zaire Ebola virus species.
Vsv-ebov is one of the vaccines for Ebola virus that is under experiment. It is a live attenuated vaccine of recombinant vesicular stomatitis viruses (rvsv). The route of administration of vaccine is nasally. This vaccine is widely used. It was observed that there is no development of symptoms or any signs on the experiment animals after vaccination. The observed levels of IgG antibody that has resistance to Zebov glycoprotein was low to moderate. Rodents and Guinea pigs that are injected with the Ebov glycoprotein vaccine vector was protected so it is an efficient and successful.
Conclusion
Ebola virus disease EVD is a deadly hemorrhagic sickness. It results because of the infection with the Ebola virus which belongs to the family Filoviridae. The disease has come out as a general public health worry because of the large foreign population and various disease outbreak in the past quarter-century. Recently, development of the virus vaccine is being taken. Moreover, an effective antiviral drug against Ebola virus being accomplished such as: Favivipavir and Remdesivir. There is no particular treatment protocol for Ebola virus disease, only supportive and symptomatic therapy is the way of treatment. Anyway, fast geographic spreading, non-specific clinical identification, unavailability of vaccine and particular diagnostic test are the possible problems that facing this harmful public health threat.
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