Caring for Patients with Ebola 

Ebola is a severe and often fatal hemorrhagic disease caused by the Ebola virus, an RNA virus in the family Filoviridae. It is characterized by high fever, gastrointestinal symptoms (vomiting, diarrhea, abdominal pain), and unexplained hemorrhage. Ebola was first recognized in the 1970s when it caused outbreaks in Zaire (now called the Democratic Republic of the Congo [DRC]) and Sudan. In subsequent years it remained endemic in regions of central Africa and caused more than 20 outbreaks in several African countries, including the Ivory Coast, DRC, Uganda and Gabon. The largest outbreak to date began in December 2013 in Guinea. The virus then spread to other West African countries, including Liberia, Sierra Leone, Nigeria, Mali, and Senegal. As of early November 2014, the epidemic remained largely uncontrolled.

Ebola is a zoonotic disease; it appears that several species of fruit bat serve as the virus' natural reservoir and that epidemics result from spillover from bats into the human population through contact with bats or their excretions/secretions. Human-to-human transmission occurs via contact with bodily fluids of an infected patient; all bodily fluids are thought to be infectious (e.g., blood, sputum, vomit, diarrhea, semen, amniotic fluid, breast milk). Portals of entry include mucus membranes and breaks in the skin. The pathogenesis of Ebola is not clear. It is thought that once in the human body, the virus replicates in a variety of cell types, including dendritic cells, monocytes and macrophages; with consequences including coagulation abnormalities, vascular instability, a robust inflammatory response and extensive focal necrosis that tends to be most severe in the liver, spleen, lymph nodes, kidney, lung and gonads. Death typically occurs secondary to a septic shock-like syndrome within 10 days of symptom onset; patients who survive ≥ 2 weeks often recover. The incubation period varies from 2 to 21 days, but is typically 8-10 days. During this time the infected patient is not contagious; the patient is not considered contagious until the onset of symptoms (typically fever). Early symptoms are nonspecific and can be confused with those of other diseases, including malaria, dengue, and typhoid fever.

The U.S. Centers for Disease Control and Prevention (CDC) recommends that Ebola be considered in patients presenting with fever > 38.0 °C (100.4 °F) and other symptoms, including severe headache, myalgias, vomiting, diarrhea, abdominal pain or unexplained hemorrhage. Patients with these symptoms should be asked about travel history to an Ebola-infected country within the 21 days prior to symptom onset. The CDC recommends screening the travel history of all patients. If the patient has symptoms consistent with Ebola and a positive recent travel history, the patient should be isolated in a private room with a private bathroom; standard, contact and droplet precautions should be implemented; and local and state health departments should be notified immediately. Individual states (e.g., California) also require airborne precautions. Definitive diagnosis of Ebola requires a reverse transcriptase-polymerase chain reaction (RT-PCR) assay demonstrating the presence of Ebola RNA; this testing can be performed in just a few high-containment laboratories throughout the world, including at the CDC in the United States. Any healthcare professional collecting specimens from patients with suspected Ebola must wear, at minimum, gloves, water-resistant gowns, full-face shield or goggles, and masks to cover the nose and mouth (for more information on collecting and transporting specimens from patients with suspected Ebola infection, see http://www.cdc.gov/vhf/ebola/hcp/interim-guidance-specimen-collection-submission-patients-suspected-infection-ebola.html). Again, some state agencies (e.g., California's Cal/OSHA) have stricter requirements to include battery-powered air purifying respirators (PAPRs).

For the purpose of caring for patients in the appropriate setting, the CDC has categorized hospitals as "Frontline Healthcare Facilities," "Ebola Assessment Hospitals" and "Ebola Treatment Hospitals." Healthcare providers (HCP) at Frontline hospitals identify relevantly exposed patients, isolate them and notify the health department. Staff should be proficient at donning and doffing personal protective equipment (PPE). Most U.S. acute care hospitals are classified as Frontline and will care for patients for up to 24 hours. HCP at Ebola Assessment Hospitals will evaluate and care for patients for up to 4-5 days. Patients in Ebola Treatment Centers will be cared for throughout the disease process. As of February 9, 2015, 51 facilities across the U.S. have been identified by CDC as Ebola Treatment Centers.

There is no cure for Ebola. Treatment includes symptom control and support, with the emphasis on balancing fluids and electrolytes, maintaining oxygen status and blood pressure, reversing coagulopathy, treating any complicating infections, and providing comfort care. Experimental drugs and treatments, including antivirals, antibodies (e.g., a cocktail of monoclonal antibodies directed at Ebola virus proteins called Zmapp), plasmapheresis and convalescent sera or blood transfusion (i.e., transfusion of sera or blood collected from a patient who has recovered from Ebola) have been used in a limited number of patients during the current epidemic. An Ebola vaccine is currently being tested in Africa.

Ebola is classified as a biosafety level 4 (BSL-4) pathogen, as well as a Category A potential bioterrorism agent, by the CDC because of its high mortality rate, person-to-person transmission, potential for aerosol transmission (although aerosol transmission has not yet been confirmed in human populations), and lack of vaccines or other treatment. Healthcare workers caring for patients with suspected or confirmed Ebola are advised to implement standard, contact, and droplet precautions, including use of full-body personal protective equipment (PPE) and strict attention to barrier isolation. In addition, some facilities are implementing airborne precautions.