The Ebola Virus

Ebola or Ebola Hemorrhagic Fever; Etiological agent – Ebola virus.

Transmission:

Transmitted through direct contact with infected body fluids, skin or mucous membrane contact. (1)

Reservoirs:

Unknown, but it seems to reside in the rain forests on the African continent and in the Western Pacific.

General characteristics:

The virus is pleomorphic, appearing as long filamentous forms in a variety of shapes. The virions have a diameter of 80 nm and a length of 970 nm. They are composed of a helical nucleocapsid and are enveloped with surface projections. (2) Identified by ELISA, IFA test, PCR, or by isolating the virus in cell culture or guinea pigs. (3)

Signs and Symptoms:

After the person is infected, the incubation period can be as short as 2 days and as long as 21 days. Common signs and symptoms can include: weakness, fever, sore throat, dehydration, severe headache, joint and muscle aches, stomach pain, diarrhea, vomiting, hacking cough. Severe bleeding and coagulation abnormalities, rash may be seen in some patients. (4) Death usually occurs during the second week of the symptoms due to massive blood loss.

Virulence Mechanisms:

Destruction of the immune system: The majority of patients infected with the virus are unable to develop sufficient immune responses. The main reason for that is the virus’s infection of the fibroblastic reticular system, which plays a role in maximizing immune responses. It is also believed that the infections from circulating monocytes and macrophages cause the transmission of virions between tissues.

Damage of the blood vessels: It is also believed that Ebola virus damages cells lining the surface of blood vessels and platelet cells. As the vessel walls get damaged and the platelet cells stop coagulating, patients lose a large portion of blood and die of shock.

Control and Treatment:

Treatment for Ebola usually includes supportive care, such as: intravenous fluids to help maintain fluids and electrolytes; different medications to control fever, help with coagulation, and maintain blood pressure; antibiotics to prevent secondary infections from bacteria. (6)

Prevention and Vaccine Information:

Prevention of the Ebola includes avoiding direct contact with body fluids of the infected with the virus and also avoiding direct contact with the body of a person who has died from Ebola. For medical professions, always wear masks, gloves, gowns, and goggles when treating Ebola infected patients; completely sterilize the equipment; isolate the infected patients from contact with unprotected people.

As of today, there is no Ebola vaccine that is currently licensed, but scientists from the National Institute of Health have conducted trial that demonstrated an immune response to the virus in humans.