Ebola Update

Abstract

The Ebola virus disease first appeared in 1976 in the Sudan and the Democratic Republic of Congo. The most recent outbreak occurred in West Africa in March 2014 and quickly spread in surrounding countries. Ebola spreads through direct contact with the body fluids of an infected individual. The incubation period for Ebola is 2 to 21 days. Individuals are infectious when symptomatic. Identifying individuals at high risk for Ebola in the United States includes early recognition of symptoms and a history of travel to an Ebola-affected area. Multiple diagnostic tests exist and should include a complete blood count and a comprehensive metabolic profile. Standard, contact, and droplet precautions are advised when taking care of patients with Ebola. Appropriate personal protective equipment as recommended by the Centers for Disease Control and Prevention should be worn. No vaccine or antiviral drug has been approved, but vaccine trials are under way. Occupational health nurses play a key role in educating employees about this disease.

On October 15, 2014, during a national webinar hosted by National Nurses United (http://www.nationalnursesunited.org/) and the Registered Nurse Response Network, nurses from around the country discussed their concerns about caring for Ebola patients. Many expressed anxiety, fear, and anger over the lack of response from their employers to the potential Ebola threat. Without exception, nurses said they had inadequate training: no opportunity to practice using personal protective equipment (PPE), 10-minute trainings, brochure-only trainings, and no demonstrations. One speaker blamed the Centers for Disease Control and Prevention (CDC) for failing to communicate with the National Institute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA). The speaker suggested that had the CDC worked with OSHA and NIOSH, occupational health professionals could have been at the forefront of this epidemic, focused on prevention.

This article provides readers with information about the Ebola virus, how it is transmitted, and other facts about this deadly disease. In addition, prevention strategies, including appropriate PPE and isolation requirements, as well as how to differentiate possible Ebola infections from other communicable diseases are addressed. Finally, this article discusses communication strategies for occupational health professionals to ensure the safety of all employees.

Epidemiology of Ebola Virus

The Ebola virus disease (EVD) first appeared in 1976 in Sudan and the Democratic Republic of Congo, initially in a village close to the Ebola river from which the disease takes its name. These outbreaks occurred in remote villages, but the most recent outbreak in West Africa (first cases reported in March 2014) occurred in major urban as well as rural areas (World Health Organization [WHO], 2014). The disease has also spread between countries starting in Guinea and then to Sierra Leone, Liberia, Nigeria, and Senegal. The most severely affected countries, Guinea, Sierra Leone, and Liberia, have limited infrastructure and health care resources (WHO, 2014).

Transmission

Ebola, previously known as Ebola hemorrhagic fever, was introduced into the human population through contact with an infected animal’s body fluids (i.e., blood, organs, or secretions). The natural reservoir host of Ebola virus remains unknown; however, researchers believe that bats are the most likely reservoir. Ebola is a rare and deadly disease caused by one of the five identified Ebola virus species, four of which are known to cause disease in humans. The fifth has caused disease in nonhuman primates (e.g., monkeys, gorillas, and chimpanzees), but not in humans (http://www.cdc.gov/vhf/ebola/about.html).

Ebola spreads through direct contact with the body fluids of an individual infected with the Ebola virus. The most infectious fluids are blood, feces, and vomit (WHO, 2014). The Ebola virus has also been detected in breast milk, urine, and semen. A convalescent male can still transmit the virus through semen for up to 70 days after symptoms appear with some studies showing up to 82 days of disease transmission. Saliva and tears are also implicated in transmission, but studies are inconclusive due to small sample sizes (WHO, 2014). The virus was found in the saliva of patients at a later stage of illness. No live virus has been isolated from sweat or vaginal secretions (WHO, 2015).

The risk of EVD transmission from direct skin contact with an EVD patient is lower than the risk of transmission via direct contact with the blood or body fluids of an infected EVD individual. According to epidemiological data from the CDC, Ebola virus RNA levels increase logarithmically during the acute phase of Ebola (www.cdc.gov/vhf/ebola/transmission/human-transmission.html).

Ebola is spread via direct contact with the blood, secretions, organs, or other body fluids through the broken skin or mucous membranes of infected individuals, and indirectly by contact with previously contaminated surfaces and objects, such as needles, syringes, bedding, clothing, and equipment used in the care of EVD-infected individuals. The risk of transmission from indirect contact is low and can be reduced with proper cleaning and disposal of instruments. If used equipment is not disposable, it must be sterilized before being used again. Without adequate sterilization of instruments, virus transmission can continue and worsen an outbreak. Preferably, disposable equipment should be used (WHO, 2015). According to the CDC, Ebola is not spread through the air or by water (CDC, 2014b). However, even though the transmission of the Ebola virus is not airborne, large droplets such as splashes or sprays of respiratory secretions from an individual sick with Ebola could be infectious (CDC, 2015b).

How did Ebola become an epidemic? This particular outbreak of Ebola is concerning because it involves the most deadly of the five Ebola viruses, the Zaire Ebola virus, which has killed 79% of the individuals it has infected in previous outbreaks (WHO, 2014). Health care workers in West Africa did not have the experience or the training to adequately address this outbreak and the infrastructure could not support the influx of infected patients. Travel between countries in Africa also spread the disease, making it difficult to track exposed and infected individuals. Social and cultural factors that might have inadvertently contributed to transmission include social stigmas, reluctance to seek health care immediately, and funeral rites that require direct contact with the corpse (WHO, 2014).

Symptoms and Risk Factors

The incubation period for Ebola, that is the time interval from infection to the onset of symptoms, is 2 to 21 days. Individuals exposed to EVD are not infectious until they develop symptoms. Initial symptoms of EVD include sudden onset of fever (i.e., subjective or ≥101.5°F or 38.6°C), severe headache, joint and muscle aches, fatigue, and sore throat. These initial symptoms are followed by abdominal pain, vomiting, diarrhea, rash, symptoms of impaired kidney and liver function, and, in some cases, both internal and external bleeding (e.g., oozing from the gums, blood in the stool). Some individuals may experience a rash, red eyes, hiccups, cough, chest pain, dyspnea, and dysphagia (CDC, 2014b, 2015a; WHO, 2014).

Identifying individuals at high risk for Ebola in the United States includes early recognition of symptoms and a history of residence in or travel to an area where EVD transmission is active (e.g., Liberia, Sierra Leon, and Guinea) 21 or less days before the onset of illness, direct contact with an EVD patient, exposure to blood or body fluids of an infected EVD individual, direct contact with a dead body in an Ebola-affected area, or direct handling of bats, rodents, or primates from disease-endemic areas (CDC, 2014b). Early recognition is crucial for infection control. Health care providers should be alert for and evaluate patients suspected of having EVD (CDC, 2014b).

Laboratory Procedures

Ebola virus is usually detectable in patients’ blood at the time of fever and symptom onset (CDC, 2014b). Specimen testing includes polymerase chain reaction (PCR)/virus isolation in whole blood, fresh frozen tissue, or serum. Diagnostic tests include antigen-capture enzyme-linked immunosorbent assay (ELISA), IgM ELISA, PCR assay, electron microscopy, and virus isolation by cell culture within a few days of symptom onset; IgM and IgG antibodies later in the EVD course or after recovery; and immunohistochemistry testing, PCR, and virus isolation by cell culture at post mortem. Laboratory testing should include a complete blood count (CBC) and a comprehensive metabolic profile to include liver enzymes (comprehensive metabolic panel [CMP]). Initial laboratory findings may include leukopenia with lymphopenia followed by elevated neutrophils and a left shift. Platelet counts often are decreased in the 50,000 to 100,000 range. Amylase may be elevated with aspartate aminotransferase (AST) exceeding alanine aminotransferase (ALT). Proteinuria may be present. Prothrombin (PT) and partial thromboplastin times (PTT) are prolonged and fibrin degradation products are elevated, consistent with disseminated intravascular coagulation (DIC; CDC, 2015a; http://www.cdc.gov/vhf/ebola/diagnosis/index.html).

Recommendations for specimen collection include full face shield or goggles, masks to cover the nose and mouth, gloves, and fluid resistant, impermeable gowns. In addition, during laboratory testing, employees should also use a certified Class II Biosafety cabinet or plexiglass splash guard as well as manufacturer-installed safety features for instruments. When obtaining samples or performing laboratory tests, established standards compliant with OSHA bloodborne pathogen regulations, which encompass blood and other potentially infectious materials, should be followed (https://www.osha.gov/SLTC/bloodbornepathogens/index.html; https://www.osha.gov/OshDoc/data_BloodborneFacts/bbfact01.pdf).

Prevention

Health care workers should always take standard precautions when caring for patients, regardless of diagnosis. Standard, contact, and droplet precautions are recommended for the management of patients with known or suspected EVD (CDC, 2015b). Health care workers who may be exposed to patients with Ebola should wear protective clothing, including masks, gloves, gowns, and eye protection. They should use established infection control and sterilization measures. Hand washing is essential. Patients suspected of having EVD should be placed in isolation. Direct contact with individuals who have died of EVD should be avoided. Health care workers should follow appropriate procedures for reporting direct contact with the blood or body fluids (i.e., feces, saliva, urine, vomit, and semen) of an individual sick with Ebola (CDC, 2015b; http://www.cdc.gov/vhf/ebola/prevention/index.html)

CDC PPE recommendations for health care workers caring for Ebola patients were updated on April 25, 2015. The recommendations can be found at http://www.cdc.gov/vhf/ebola/hcp/procedures-for-ppe.html. Guidance from the CDC includes the procedures and processes involved in “donning and doffing” PPE for all health care workers entering the room of a patient with EVD. The guidelines are specific and based on lessons learned from the recent experiences of specific U.S. hospitals admitting EVD patients (CDC, 2015a).

Waste generated in the care of EVD patients is another issue that health care workers and institutions must address. Procedures to dispose of waste fall under local, state, and federal regulations. Basic principles for handling blood and body fluids are outlined in OSHA’s Bloodborne Pathogen standard 29 CFR 1910.1030 (https://www.osha.gov/SLTC/bloodbornepathogens/index.html).

The CDC recommends autoclaving or incinerating waste contaminated with Ebola. (http://www.cdc.gov/vhf/ebola/hcp/medical-waste-management.html). Waste contaminated (or suspected to be contaminated) with Ebola virus is a Category A infectious substance regulated as a hazardous material under the U.S. Department of Transportation’s (DOT) Hazardous Materials Regulations (HMR; 49 C.F.R., Parts 171-180). Once Ebola waste is incinerated, it is no longer considered infectious or a health hazard (CDC, 2014b). Some states such as California prohibit incineration (burning) of health care waste (http://www.latimes.com/science/la-sci-ebola-waste-disposal-20141020-story.html) that presents a potential problem in transporting waste on public highways and incinerating it in other states. Discussions to lift the restriction for health care waste incineration in these states are ongoing. California’s last medical incinerator closed in 2001, and waste is transported to an out-of-state medical incinerator in Alabama, Maryland, North Dakota, Oklahoma, Utah, or Texas (California Department of Public Health, 2015).

Case Fatality Rate (CFR)

The CFR is the number of deaths per number of cases of disease (Aschengrau & Seage, 2008). The CFR is calculated by dividing the number of deaths that have occurred due to a disease (such as Ebola) by the total number of cases. A CFR is expressed as a percentage and represents a measure of risk. CFRs are most often used for diseases with discrete, limited time intervals, such as outbreaks of acute infections. The WHO (2014) released a report that cited 4,293 total cases of Ebola and 2,296 deaths around the world as of September 5, 2014 (http://apps.who.int/iris/bitstream/10665/132687/1/roadmapsitrep2_eng.pdf?ua=1). Dividing 2,296 by 4,293 gives a case fatality rate of 53% or 53 per 100. The range is from 39% in Sierra Leone to 64% in Guinea. The temporal feature (January 1, 2014 to September 5, 2014) of a case fatality rate gives a “snapshot” of deaths per number of cases of disease in a given time (WHO, 2014).

Treatment

No vaccine or antiviral drug for Ebola has been approved by the Federal Drug Administration (FDA). In January 2015, two vaccines were tested in large studies in the West African countries most affected by the Ebola outbreak (WHO, 2014). On April 14, 2015, the CDC in partnership with the Sierra Leone College of Medicine and Allied Health Sciences (COMAHS) and the Sierra Leone Ministry of Health and Sanitation (MoHS) began enrolling and vaccinating volunteers for the Sierra Leone Trial to Introduce a Vaccine Against Ebola (STRIVE) trial. This study will assess the safety and efficacy of the rVSV-ZEBOV Ebola vaccine among health and other frontline workers (CDC, 2015c).

Patients are currently given supportive care and symptoms are treated as they appear. When symptoms are treated early, the chance of survival improves (CDC, 2014a). Treatment can include intravenous fluids, balancing electrolytes, maintaining blood pressure and oxygenation, and treating infections as they appear. Individuals do recover from Ebola, depending on the quality of supportive care and each individual’s immune response. Those individuals who recover from Ebola develop antibodies that last for at least 10 years. Complications such as joint and vision impairments have been reported in those who have recovered (CDC, 2014a).

Resources

The Centers for Disease Control and Prevention (CDC) has numerous resources on their website, http://www.cdc.gov/vhf/ebola/hcp/index.html, including guidelines for preparedness and response such as a checklist for hospitals, health care providers, and emergency services on how to manage patients suspected of contracting Ebola. Local health departments are also a source of support and guidance for health care providers screening or caring for patients suspected of Ebola exposure. The WHO (http://www.who.int/csr/disease/ebola/en/) offers training courses to prepare health care providers to care for patients with Ebola and provides updates on the spread of Ebola worldwide. The American Association of Occupational Health Nurses (AAOHN) has provided a link to the most current and trusted sources for EVD information (aaohn.org/component/content/article/12-practice/445-ebola-resources-guide.html).

Implications for Occupational Health Nurses

Occupational health nurses must educate employees, colleagues, and communities about the Ebola virus. Nurses often work in environments with real or potential health threats. The role of the occupational health nurse in the Ebola epidemic is to stay abreast of evolving information about EVD, its history, transmission, symptoms, risk factors, and prevention strategies. Also crucial to the safety of occupational health nurses is the appropriate use of PPE per guidelines provided by the CDC. Support from health care institutions, such as hospitals, in the adoption of guidelines set forth by the CDC and WHO is paramount to the safety of health care workers in the United States and around the world.

By staying informed, the occupational health nurse can educate workers, lower anxiety, and prevent hysteria. When the occupational health nurse educates employees, they are empowered by knowing about these health issues and how to manage them. The occupational health nurse should refer employees to appropriate and trusted resources such as the CDC, WHO, and state health departments to gain factual information about EVD. Professional organizations, such as AAOHN, are also a reputable source of information.

Occupational health nurses should monitor employees’ health status, investigate health hazards in the environment, and enforce regulations that protect health and ensure safety. Occupational health nurses should participate in policy development that supports individual and community health efforts while advocating for employees’ health and safety. For example, this includes the development of protocols to guide workers in the case of an exposure, definition of an exposure, identification of appropriate post-exposure procedures, and informed decision-making regarding workers’ health and safety.

Conclusion

Early recognition is critical to control transmission from Ebola-exposed individuals. Health care providers should be alert for and evaluate individuals suspected of contracting Ebola. EVD should be suspected in anyone with fever, headache, muscle pain, weakness, diarrhea, vomiting, abdominal pain, or unexplained hemorrhage, and who has traveled to West Africa (i.e., Guinea, Liberia, Sierra Leone, or other countries where EVD transmission has been reported by WHO) or had contact with a suspected or confirmed EVD patient within 21 days of symptom onset (CDC, 2014b). Because of the rapid, almost daily updates provided by the CDC and WHO, it is essential that occupational health nurses remain current during this epidemic. Current information will ensure that occupational health nurses are sharing appropriate evidence-based information with worker populations.

In Summary

• EVD transmission is through direct contact with broken skin or mucous membranes.

• Identification of individuals at high risk for EVD includes recognition of symptoms and a history of travel or residence in an area where EVD transmission is active.

• Standard, contact, and droplet precautions are recommended for patient management.

• Occupational health nurses are responsible for educating employees, colleagues, and communities about EVD. It is important to stay up-to-date with information regarding EVD and the appropriate guidelines for PPE use when there is a potential exposure.

• Trusted sources of information include sites such as the CDC, WHO, and AAOHN.