Ebola hemorrhagic fever

Definition

Ebola hemorrhagic fever is a severe and often deadly illness that can occur in humans and in primates (monkeys, gorillas).

Ebola hemorrhagic fever has made worldwide news because of its destructive potential.

Alternative Names

Ebola virus infection; Viral hemorrhagic fever

Causes, incidence, and risk factors

Ebola hemorrhagic fever (Ebola fever) is caused by a virus belonging to the family called Filoviridae. Scientists have identified four types of the Ebola virus. Three have been reported to cause disease in humans: Ebola-Zaire virus, Ebola-Sudan virus, and Ebola-Ivory Coast virus. The human disease has so far been limited to parts of Africa.

A very small number of people in the United States who were infected with the fourth type of the virus, known as Ebola Reston, did not develop any signs of disease.

The disease can be passed to humans from infected animals and animal materials. Ebola can also be spread between humans by close contact with infected bodily fluids or through infected needles in the hospital.

Symptoms

During the incubation period, which can last about 1 week, symptoms include:

• Arthritis
• Backache (low-back pain)
• Chills
• Diarrhea
• Fatigue
• Fever
• Headache
• Malaise
• Nausea
• Sore throat
• Vomiting

Late symptoms include:

• Bleeding from eyes, ears, and nose
• Bleeding from the mouth and rectum (gastrointestinal bleeding)
• Depression
• Eye inflammation (conjunctivitis)
• Genital swelling (labia and scrotum)
• Increased feeling of pain in skin
• Rash over the entire body that often contains blood (hemorrhagic)
• Roof of mouth looks red
• Seizures, coma, delirium

As many as 90% of patients die from the disease. Patients usually die from shock rather than from blood loss.

Signs and tests

There may be signs and symptoms of:

• Coma
• Disseminated intravascular coagulation
• Shock

Tests used to diagnose Ebola fever include:

• CBC
• Electrolytes
• Tests of how well the blood will clot (coagulation studies)
• Tests to show whether someone has been exposed to the Ebola virus

Treatment

There is no known cure. Existing medicines that fight viruses (antivirals) do not work well against Ebola virus.

The patient is usually hospitalized and will most likely need intensive care. Supportive measures for shock include medications and fluids given through a vein.

Bleeding problems may require transfusions of platelets or fresh blood.

Expectations (prognosis)

As many as 90% of patients die from the disease. Patients usually die from shock rather than blood loss.

Complications

Survivors may have unusual problems, such as hair loss and sensory changes.

Calling your health care provider

Call your health care provider if you have traveled to Africa (or if you know you have been exposed to Ebola fever) and you develop symptoms of the disorder. Early diagnosis and treatment may improve the chances of survival.

Prevention

Avoid areas in which there are epidemics. Wear a gown, gloves, and mask around sick patients. These precautions will greatly decrease the risk of transmission.

References

Bell M. Viral hemorrhagic fevers. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier. 2007: chap 404.

Peters CJ. Marburg and ebola virus hemorrhagic fevers. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 6th ed. Philadelphia, Pa: Churchill Livingstone Elsevier; 2005: chap 161.