Ebola: The Basics
By Darrell Hulisz, RPh, PharmD
Ebola virus is a single-stranded RNA filovirus first recognized in 1967, when monkeys were imported from Uganda for Polio vaccine production. Ebola infection causes severe hemorrhagic fever in humans that resembles septic shock. A highly virulent, mutating virus, Ebola has an estimated fatality rate in West Africa of approximately 70%.
In March 2014, the World Health Organization (WHO) confirmed that an outbreak of Ebola had begun in late 2013 and had originated in Guinea. The current outbreak in West Africa is the largest one ever recorded; as of December 3, 2014, the CDC reported an estimated 17,145 total cases, including 6,070 deaths. In response to the outbreak, public health authorities in the United States are actively monitoring travelers arriving from Liberia, Sierra Leone and Guinea.
Patients infected with Ebola typically begin to experience symptoms eight to 12 days after exposure. The incubation period is believed to last two to 21 days. No evidence currently exists to support the belief that asymptomatic individuals are infectious within the incubation period; however, symptomatic individuals are assumed to be contagious. Any person suspected of infection with Ebola should be isolated until the virus has been ruled out. Initial signs and symptoms of infection include non-specific flu-like symptoms, abrupt onset of fever, chills, malaise, anorexia, severe headache, muscle pain, nonproductive cough and pharyngitis.
Within a week many patients develop a diffuse erythematous, nonpruritic, maculopapular rash that affects the face, trunk and arms. Gastrointestinal symptoms such as diarrhea, nausea, vomiting and abdominal pain appear several days after initial presentation. Coagulation changes resulting in thrombocytopenia and hemorrhage develop later in the disease, manifest as petechiae, bruising, oozing from venipuncture sites, and/or mucosal hemorrhage. Multisystem organ failure, shock, and death may occur.
Person-to-person transmission occurs through direct contact of broken skin or unprotected mucous membranes with virus-containing body fluids from a person who has signs and symptoms of the disease. The most infectious bodily fluids include blood, feces and vomit. Other bodily fluids that contain the virus include urine, semen, breast milk, saliva and tears. Although aerosolized Ebola virus is highly contagious for laboratory animals, the virus is probably not easily spread by airborne transmission in humans. Ebola may be transmitted though contact with surfaces and objects that have been contaminated with the virus. Humans can also become infected if they come into contact with wild animals that have the virus.
There are no FDA approved medications for the treatment of Ebola. The mainstay of treatment for Ebola virus remains supportive care while waiting on the immune system to mount a response. The most important aspects of supportive care include hydration, correction of electrolyte abnormalities, and avoiding complications of shock. Another treatment strategy is the administration of whole blood or serum from patients recovering from the Ebola virus. Additionally, there are several other experimental medications that have been used to treat patients in West Africa.
No vaccine for Ebola is available, though several vaccine candidates are currently undergoing Phase I clinical trials and are expected to start Phase II trials in early 2015.
Current CDC Ebola recommendations for health care providers are as follows: If a person presents with viral symptoms, take a travel history. Consider Ebola in patients with a fever greater than 100.4° F, severe headache, muscle pain, diarrhea, vomiting, stomach pain, or unexplained bruising or bleeding 21 days after traveling from Guinea, Liberia, Nigeria, or Sierra Leone. Health care providers should immediately take infection control precautions and contact their state or local health department if they have questions.
Keep up-to-date on infection prevention principles with the RN.com CE course, “Infection Prevention for Healthcare Professionals” (3 contact/hours). This course is also approved by the Commission on Case Manager Certification.
Bausch, D.G., Towner, J.S., Dowell, S.F., et al. (2007). Assessment of the risk of Ebola virus transmission from bodily fluids and fomites. J Infect Dis; 196 Suppl 2:S142.
Centers for Disease Control and Prevention [CDC]. (2014). Ebola virus disease information for clinicians in U.S. healthcare settings Retrieved from: http://www.cdc.gov/vhf/ebola/hcp/clinician-information-us-healthcare-settings.html
Feldmann, H., Geisbert, T.W. (2011). Ebola haemorrhagic fever. Lancet; 377:849.
Fowler, R.A., Fletcher, T., Fischer, W.A. 2nd, et al. (2014). Caring for critically ill patients with Ebola virus disease. Perspectives from West Africa. Am J Respir Crit Care Med; 190:733.
Hampton, T. (2014). Largest-ever outbreak of Ebola virus disease thrusts experimental therapies, vaccines into spotlight. JAMA; 312:987.
Darrell Hulisz, currently practices as a clinical pharmacist with University Hospitals of Cleveland, Family Medicine Residency Program, where he works in consultation with family physicians, both on inpatient and outpatient services. He is a webinar speaker at RxSchool.com, where he presents live courses and contributes to the site’s CE curriculum.
A version of this article was previously published on our sister site, PharmacyChoice.com
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