Ebola Virus

Ebola is a deadly disease caused by a virus. Ebola virus disease (EVD) or Ebola hemorrhagic fever (EHF) is a severe, often fatal illness caused by the Ebola virus in humans. The Ebola virus is transmitted from animals to humans, then from humans to other humans. The disease is spreading in the West African region. The disease is spread quickly from person to person and is highly contagious. The Ebola virus kills in a short period of time, but can be prevented from spreading. The disease started in 1976 in Sudan and in Congo near the Ebola River; this is how the virus took its name. The mortality rate was 90%, now it is about 50%.

The Ebola virus affects people living near tropical rainforests. The infected people are usually quarantined and the people they have been in contact with should be tracked and observed for 21 days for signs and symptoms of the disease. The virus may be acquired upon contact with infected animals. For example, a fruit bat contaminated with the Ebola virus eats fruit, infecting the fruit with the virus. When the bat drops the fruit to the ground, it will be eaten by other animals who will then become infected with Ebola. The fruit bat is considered to be the primary carrier of this disease, although it does not become infected. Ebola also affects chimpanzees, monkeys, gorillas, and porcupines. The virus can be transmitted through the organs or the bodily fluids of the infected animals, especially monkeys and bats. Eating bush meat of the infected animals is a problem. It can be passed on through ingesting the meat of infected animals (bush meat) such as bats and monkeys. In these tropical areas some people have become accustomed to eating monkey meat. People buy the meat and eat it without knowing if it is infected with the Ebola virus. The Ebola virus passes to humans through direct contact with bodily fluids, such as sweat, saliva, blood, secretions, vomit, stool, or urine. The virus passes from human to human through broken skin, wounds, mucous membranes, blood, or a contaminated environment or equipment. Ebola can be contracted from an infected person even after death. In some cultures, mourners may come in direct contact with the virus during the bathing of the body of the deceased. Men who recover from the disease can transmit the virus through their semen for up to seven weeks. The Ebola virus is not transmitted through air. It is not an airborne virus! Ebola is not contagious until the person begins to show symptoms. Healthcare workers are at risk of coming into direct contact with the disease. They may not know the patient is infected with the virus and it is advisable to use biohazard suits and wash as well as use disinfectant on the hands, instruments, and equipment.

With the loss of faith in medicine and hospitals, sick patients could believe their disease may not be cured in a hospital and resort to a traditional healer. This may spread the disease further within the community. Educational, behavioral, and cultural changes are needed to stop the spread of Ebola. It is easier to control the spread of the disease within the rainforests and isolated areas. It is harder to control the disease in densely populated areas. Adequate quarantine and containment may be difficult.

The incubation period is usually 2-21 days. This is the time period from getting the infection to becoming symptomatic. There are no early warning signs to identify the disease. Any person who has had direct contact with an infected patient should be followed for three weeks. Initially, the disease is flu-like. People are suspected of infection if they have a fever, diarrhea, and a travel history to a suspicious region. Laser thermal scanners are used at the point of entry at the airports to detect febrile illness (fever). This screening tool may yield a high false positive result. Because a person may not show symptoms of the disease for several weeks, they may travel thinking they are healthy and then accidentally spread the disease.

Symptoms of Ebola in its early stages are flu-like, and include fever, muscle pain, weakness, sore throat, and headache. Later on, the patient may develop vomiting, diarrhea, rash, as well as internal and external bleeding, organ failure, and impaired liver and kidney function.

About 50% of patients develop a rash. Early symptoms may be similar to flu, malaria, tropical fever, and others, so the diagnosis can be missed. The patient becomes contagious and the health care professionals may contract the disease. The condition of the patient deteriorates once the symptoms appear. The quick onset of symptoms make it easy to identify sick individuals and limit the person’s ability to travel and spread the disease.

The main targets of the Ebola infection are:

• Phagocytes (immunity)- infection
• Endothelial cells (blood vessels)- bleeding
• Hepatocytes (liver cells)- liver failure

The Ebola virus multiplies quickly and overwhelms the immune system, making it difficult to fight the infection. Bleeding usually occurs from the eyes, ears, nose, and rectum. The patient may vomit blood or cough up blood. The patient may bruise very easily and there may be internal and external bleeding. The patient may get hypotension and shock from bleeding (rare). Bleeding could indicate a worse prognosis. Coagulation and liver function tests are needed. It is called the Ebola hemorrhage fever because the virus causes the walls of capillaries to separate, which starts leaking of the blood, including bleeding into the eyes, mouth, and other areas. Blood loss is not what causes death to the patient. Multiple organ failure and system shut down is what ultimately causes death. The virus appears to be filamentous in the shape of a shepherd’s crook, the letter U or the number 6. They may be coiled, toroid, or branched. There are several strains of the Ebola virus. The worse strain of the Ebola virus is the Zaire Ebola virus (ZEBOV) strain.

After a cell captures the Ebola virus, it will imprison the virus inside a visible awaiting elimination. The virus reacts to the PH (acidity) inside the vesicle. This causes a molecule on the surface of the virus to form a fist called a glycoprotein. This fist allows the virus to punch through the vesicle wall and escape into the cytoplasm. The Ebola virus moves into the cell’s cytoplasm where the virus converts the cell into a factory and begins replicating and making copies of itself. The RNA of the virus is let out into the cell and is replicated. It then causes havoc on the cell.

A diagnosis will be made based off of the patient’s medical and travel history. Confirmation of the presence of the virus in the patient’s blood is needed. Diagnosis is done by isolating the virus by cell culture utilizing election microscopy, or detecting its RNA by polymerase chain reaction (PCR), or by detecting tis protein with the ELISA test. These tests are helpful early in the disease or after the death of the patient. A real time diagnosis is usually done by PCR or ELISA test. Detecting antibodies against virus in a person’s blood is effective later in the disease or in survivors. New techniques may utilize saliva and urine samples.

Treatment is directed towards treating the patient and preventing the spread of the disease. Early treatment in healthy individuals, not immunocompromised individuals, will increase the chance of survival. There is no vaccine, antibiotics, or cure for Ebola that is currently available. A vaccine is in the process of being developed and experimental drugs are also being used. Testing for Ebola should be done with a high level of protection from biohazardous materials for health professionals. The patient is usually dehydrated and will be given IV fluids and electrolytes; oxygen, pain control, and antibiotics. Then, the physician will have to wait for the patient’s condition and immune system to improve. Death can occur from multiple organ failure. Quarantine and containment is the best protection against the spread of Ebola in addition to the use of standard precautions and personal protection. Handwashing, disinfectant, and biohazard suits should be used.