Ebola Virus Disease (EVD)

Ebola is highly contagious and frequently fatal, and it spreads through blood and body fluids, including from people who have died. There is no licensed antiviral in the US, so early supportive care (fluids, electrolytes, oxygen, blood pressure support) is what improves survival. Strict barrier precautions protect you and everyone else, because caregivers and those preparing bodies for burial are at very high risk.

EVD is caused by five strains of the Ebola virus, which affect humans and animals such as pigs, monkeys, chimpanzees, and gorillas. First discovered in 1976, it has caused several outbreaks in Africa and reached Italy, Spain, Russia, the Philippines, the USA, and the United Kingdom.

What is Ebola Virus Disease (EVD)?

EVD is a highly contagious disease causing fever, weakness, diarrhea, and unexplained bleeding.

• It was previously called Ebola hemorrhagic fever because the virus circulates through the body, harms the immune system and organs, and eventually causes severe uncontrollable bleeding.
• Ebola virus was first discovered in 1976 near the Ebola River in what is now the Democratic Republic of Congo. The viruses are located mainly in sub-Saharan Africa.
• Exposure may be primary (presence in an Ebolavirus-endemic area) or secondary (human-to-human or primate-to-human transmission).

Classification

The five ebolavirus species are named for the locations of documented human or animal disease.

• Sudan ebolavirus and Zaire ebolavirus. Two African species responsible for most reported deaths. Zaire ebolavirus is the most lethal of all species.
• Ivory Coast ebolavirus. Clinical disease from African-derived Ebola virus is severe. Except for one patient who survived infection with this third African species, mortality ranges from 65% (Sudan, 1979) to 89% (Democratic Republic of the Congo [DRC], December 2002 to April 2003).
• Reston ebolavirus. A fourth species, first isolated in 1989 in monkeys imported from a single Philippine exporter. A virtually identical isolate from the same exporter was detected in 1992 in Siena, Italy.
• Bundibugyo ebolavirus. The fifth species, also African, caused an outbreak in Uganda in 2007-2008 with a mortality of 25%.

Pathophysiology

Ebola virus has a nonsegmented negative-stranded RNA genome containing 7 structural and regulatory genes.

• After infection, human and nonhuman primates undergo rapid viral multiplication that, in lethal cases, is paired with an ineffective immunologic response.
• Viral replication is accompanied by widespread, severe focal necrosis. The most severe necrosis occurs in the liver, associated with Councilman-like bodies similar to those in yellow fever.
• In fatal infections, the host's tissues and blood contain large numbers of Ebola virions, and tissues and body fluids are highly infectious.

Causes

People are initially infected through contact with an infected animal, such as a fruit bat or nonhuman primate (a spillover event). The virus then spreads person to person.

• Contaminated blood or body fluids. Blood or body fluids (urine, saliva, sweat, feces, vomit, breast milk, semen) of a person sick with or dead from EVD.
• Contaminated objects. Clothes, bedding, needles, and medical equipment contaminated with body fluids from a person sick with or dead from EVD.
• Vectors. Infected fruit bats or nonhuman primates such as apes and monkeys.
• Contaminated semen. Semen from a man who recovered from EVD (oral, vaginal, or anal sex). The virus can remain in certain body fluids, including semen, even after symptoms resolve. There is no evidence Ebola spreads through vaginal fluids from a woman who has had Ebola.

Statistics and Incidences

EVD, one of the deadliest viral diseases, was discovered in 1976 when two consecutive outbreaks of fatal hemorrhagic fever occurred in different parts of Central Africa.

• The first outbreak occurred in the Democratic Republic of Congo (formerly Zaire) in a village near the Ebola River, which gave the virus its name. The second occurred in what is now South Sudan, approximately 500 miles (850 km) away.
• On May 8, 2018, a new outbreak was declared in the DRC after laboratory confirmation of two cases. Before confirmation, 21 patients with signs of hemorrhagic fever had been reported, 17 of whom died.
• As of September 17, 2019, 3,034 confirmed cases and 111 probable cases had been reported, including 2,103 attributable deaths.
• The 2014-2016 outbreak primarily involved three African countries: Guinea, Liberia, and Sierra Leone.

Clinical Manifestations

Symptoms appear 2 to 21 days after contact, averaging 8 to 10 days.

• "Dry" symptoms. The illness typically starts with fever, aches and pains, and fatigue.
• "Wet" symptoms. It progresses to diarrhea and vomiting as the patient worsens.
• Late-stage. Other symptoms include red eyes, skin rash, and hiccups.

Assessment and Diagnostic Findings

The FDA granted emergency authorization for two tests that detect Ebola in blood or urine samples in 1 hour. They can be performed onsite in hospitals with proper lab equipment from the manufacturer, BioFire Defense.

• Basic blood tests. Early infection shows thrombocytopenia, leukopenia, and pronounced lymphopenia. Neutrophilia develops after several days, as do elevations in aspartate aminotransferase and alanine aminotransferase. Bilirubin may be normal or slightly elevated.
• Studies for isolating virus. Definitive diagnosis rests on isolating the virus by tissue culture or reverse-transcription polymerase chain reaction (RT-PCR) assay.
• IgM-capture ELISA. Uses Zaire ebolavirus antigens grown in Vero E6 cells to detect IgM antibodies. Results turn positive in experimental primates within 6 days of infection but do not stay positive for extended periods.
• IgG-capture ELISA. Uses detergent-extracted viral antigens to detect IgG anti-Ebola antibodies. More specific than the IFAT and positive for long periods.

Medical Management

Used early, basic interventions significantly improve survival:

• Fluids and electrolytes. Provide IV fluids and electrolytes (body salts).
• Oxygen therapy. Maintain oxygen status.
• Medications. Support blood pressure, reduce vomiting and diarrhea, and manage fever and pain.

Pharmacological Management

There is no antiviral drug licensed by the FDA to treat EVD. A vaccine is approved in the United States and Europe to prevent disease caused by Zaire ebolavirus in patients aged 18 years or older.

• Ebola Zaire vaccine (Ervebo). Recombinant vesicular stomatitis virus-Zaire ebolavirus (rVSV-ZEBOV; V920) is a replication-competent vaccine, genetically engineered to express a Zaire ebolavirus glycoprotein and provoke a neutralizing immune response, indicated for prevention of disease caused by Zaire ebolavirus.

Nursing Management

Nursing Assessment

• History. Two types of exposure are recognized:
• Primary. Travel to or work in an Ebola-endemic area such as the DRC (formerly Zaire), Sudan, Gabon, or Côte d'Ivoire. Exposure to tropical African forests is more common than exposure within cities in the same region.
• Secondary. Human-to-human or primate-to-human exposure. In each major outbreak, medical personnel and family members who cared for patients or prepared bodies for burial were at very high risk.
• Physical exam. Findings depend on the stage. Early on, patients may show fever, pharyngitis, and severe constitutional signs. A maculopapular rash, more easily seen on white skin than dark skin, may appear around day 5 of infection and is most evident on the trunk.

Nursing Diagnosis

• Risk for bleeding related to impaired clotting factors.
• Risk for electrolyte imbalance related to decreased oral intake, vomiting, and diarrhea.
• Risk for shock related to progressive multi-organ failure.
• Pain related to musculoskeletal and abdominal aches.
• Risk for fluid volume deficit related to restricted oral intake, bleeding, vomiting, and diarrhea.

Nursing Care Planning and Goals

• Prevent bleeding.
• Restore normal fluid and electrolyte balance.
• Prevent shock.
• Relieve pain.
• Restore normal body fluid volume.

Nursing Interventions

• Prevent bleeding. Have the patient use a soft-bristled toothbrush and nonabrasive toothpaste, limit straining with bowel movements, forceful nose blowing, coughing, or sneezing, and take care with sharp objects. When lab values are abnormal, administer blood products as prescribed.
• Restore fluid and electrolyte balance. Give electrolyte replacements as prescribed, monitor intake and output, note decreased urinary output and positive fluid balance on 24-hour calculations, and give oral fluids with caution.
• Prevent shock. Monitor daily weight for sudden decreases, especially with decreasing urine output or active fluid loss, and watch closely for cardiovascular overload, difficulty breathing, pulmonary edema, jugular vein distention, and abnormal labs.
• Relieve pain. Provide rest periods, choose the appropriate pain relief method, remove additional stressors, and give analgesics as ordered while monitoring effectiveness and adverse effects.
• Restore fluid volume. Encourage the prescribed fluid intake; if the patient tolerates oral fluids, give the fluids they prefer; keep fluid and a straw within reach; emphasize oral hygiene, nutrition, and hydration.

Evaluation

Goals are met when the patient avoids progression of bleeding, restores fluid and electrolyte balance, avoids shock, gets pain relief, and restores normal body fluid volume.

Documentation Guidelines

• Individual findings, including factors affecting, interactions, nature of social exchanges, and specifics of individual behavior.
• Cultural and religious beliefs and expectations.
• Plan of care.
• Teaching plan.
• Responses to interventions, teaching, and actions performed.
• Attainment or progress toward the desired outcome.

Key Points

• EVD is a rare, deadly disease in people and nonhuman primates.
• Two African species, Sudan ebolavirus and Zaire ebolavirus, are responsible for most reported deaths.
• After infection, primates undergo rapid viral multiplication paired with an ineffective immunologic response in lethal cases.
• People are initially infected through contact with an infected animal such as a fruit bat or nonhuman primate (spillover), then the virus spreads person to person.
• Symptoms (fever, aches, fatigue) appear 2 to 21 days after contact, averaging 8 to 10 days.
• Two FDA-approved tests detect Ebola in blood or urine in 1 hour, performed onsite with proper lab equipment from BioFire Defense.
• Early fluids, electrolytes, oxygen, and medications significantly improve survival.