Ebola virus infection
One of the most frightening viruses to come out of the African subcontinent, the Ebola virus first appeared in 1976. More than 400 persons in Zaire (now known as the Democratic Republic of Congo) and the neighboring Sudan died because of the hemorrhagic fever that the virus causes. Ebola virus has been responsible for several outbreaks since then, including one that occurred in Zaire in the summer of 1995.
An unclassified ribonucleic acid (RNA) virus, Ebola virus is morphologically similar to the Marburg virus. Both viruses cause headache, malaise, myalgia, and high fever, progressing to severe diarrhea, vomiting, and internal and external hemorrhage.
Four strains of the Ebola virus are known to exist: Ebola Zaire, Ebola Sudan, Ebola Tai, and Ebola Reston. All four types are structurally similar but have different antigenic properties. One type, Ebola Reston, affects only monkeys; the other three types affect humans.
The prognosis for Ebola virus disease is extremely poor, with a mortality rate as high as 90%. The incubation period ranges from 2 to 21 days.
Causes
Ebola virus disease is caused by an unclassified RNA virus that’s transmitted by direct contact with infected blood, body secretions, or organs. Nosocomial and community-acquired transmission can occur. The virus remains contagious even after the patient has died.
Signs and symptoms
The patient’s health history usually reveals contact with an infected person. However, no clear line of infection may be apparent at the beginning of an Ebola virus outbreak. The patient usually complains of flulike signs and symptoms, such as headache, malaise, myalgia, fever, cough, and sore throat, which first appear within 3 days of infection.
As the virus spreads through the body, inspection reveals bruising as capillaries rupture and dead blood cells infiltrate the skin. A maculopapular eruption appears after the 5th day of infection, followed by desquamation. The patient may also display melena, hematemesis, epistaxis, and bleeding gums. At day 10 or 12, the fever may break and the patient eventually recovers. If the infection progresses, severe complications, including liver and kidney dysfunction, dehydration, and hemorrhage, may develop. In pregnant women, Ebola virus disease leads to abortion and massive hemorrhage.
Diagnosis
Specialized laboratory tests reveal specific antigens or antibodies and may show the isolated virus. As with other types of hemorrhagic fever, tests also demonstrate neutrophil leukocytosis, hypofibrinogenemia, thrombocytopenia, and microangiopathic hemolytic anemia.
Treatment
No cure exists for Ebola virus disease; treatment consists mainly of intensive supportive care. The administration of I.V. fluids helps offset the effects of severe dehydration. Treatment of associated disseminated intravascular coagulation is controversial.
Experimental treatments include administration of plasma that contains Ebola virus–specific antibodies. Although this treatment has reduced levels of Ebola virus in the body, further evaluation is needed.
Throughout treatment, the patient should remain in isolation. If diagnostic tests indicate that the patient is free from the virus, which typically occurs 21 days after onset in those few who survive, the patient can be released.
Special considerations
❑ Follow the guidelines for strict isolation precautions formulated by the Centers for Disease Control and Prevention (CDC) when assessing a patient who may have Ebola virus disease. Also take precautions to help prevent the spread of the disease. (See Preventing the spread of Ebola virus.)
❑ Check the results of complete blood count and coagulation studies for signs of blood loss and coagulopathy.
❑ Assess the patient daily for petechiae, ecchymoses, and oozing blood. Note and document the size of ecchymoses at least every 24 hours.
❑ Protect all areas of petechiae and ecchymoses from further injury.
❑ Test stools, urine, and vomitus for occult blood.
❑ Watch for frank bleeding, including GI bleeding and, in women, menorrhagia. Note and document the amount of bleeding at least every 24 hours.
❑ Monitor the patient’s family and other close contacts for fever and other signs of infection.
❑ Provide emotional support for the patient and family during the course of this devastating disease. Encourage them to ask questions, and discuss any concerns they have about the disease and its treatment.
Pictures
Book Source Details
- Book Title: Handbook of Diseases
- Author(s): Springhouse
- Year of Publication: 2003
- Copyright Details: Handbook of Diseases, Copyright © 2003 Lippincott Williams & Wilkins.
Other Book Chapters Related to Infection
Read excerpts from these other book chapters related to Infection:
Copyright Details: Handbook of Diseases, Copyright © 2008 Williams & Wilkins.
More About Causes of Infection
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More About This Book:
Title: Handbook of Diseases
Authors: Springhouse
Publisher: Lippincott Williams & Wilkins
Copyright: 2003
ISBN: 1-58255-266-5
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