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The Ebola Virus: What EMS Providers Need to Know
Starting with the AIDS epidemic of the 1980s, there exists today a fear that certain viruses, like Ebola, will create a widespread—even global—pandemic, resulting in the apocalyptic scenario of zombies walking the Earth. The first responder community may not ever be at risk of coming in contact with a patient infected with Ebola, but knowing how the virus is transmitted shows protection through early identification of symptoms, and following what the CDC terms “universal precautions,” provides an almost impenetrable barrier for all bloodborne pathogens.
Epidemiology
The Ebola virus was first discovered in 1976, during possibly simultaneous outbreaks in both the central African country of Sudan—in the southern town of Nzara, near the Ebola River—and in what is now the Democratic Republic of the Congo (formally Zaire), in the town of Yambuku. In Nzara it went on to infect over 250 people with a mortality rate of 53%. In Yambuku, it was an even more virulent and deadly strain that infected over 300 people. Named “EBOZ,” this strain had a staggering mortality rate of 88%, which prompted the World Health Organization to label it “one of the most virulent diseases known to humankind.”
The Ebola virus was first detected in the United States in 1989, when infected monkeys were imported from the Philippines to a research lab in Reston, VA. While this new strain, labeled “Ebola-Reston,” did not cause any deaths, it confirmed the fact that it was capable of zoonotic transmission, meaning it was able to pass from one species to another. In 1994, a zoologist became infected while performing an examination of a dead chimpanzee from the Tai Forest on the Ivory Coast. This reinforced the theory that the virus remains active in dead bodies, and can be transmitted even during embalming procedures.
2014 Outbreak Timeline of Events
The current outbreak, as of September 21, has nearly 6,300 suspected cases, with over 2,900 deaths throughout Guinea, Liberia, Nigeria, Senegal and Sierra Leone. This represents the largest confirmed outbreak since its discovery, and it dwarfs the second largest outbreak of 451 cases in 2000. The World Health Organization has determined “Patient Zero” was a two year old boy from Guinea who died on December 6, 2013. His mother became infected as well and passed away soon after, but the virus slowly spread through the family and those who had close contact with their dead bodies. It wasn’t until March 19, 2014 that the country’s Ministry of Health acknowledged the outbreak, stating 35 people were infected and 23 had died. The Centers for Disease Control (CDC) and World Health Organization (WHO) began investigating, and on March 31 had found 112 cases with 70 deaths, including two patients now in Liberia who had recently travelled from Guinea. In May, confirmed cases were discovered in Sierra Leone and in August a Liberian Ministry of Finance official who travelled to Lagos, Nigeria, began experiencing symptoms. He later died, as well as a doctor who was treating him. A nurse from the same hospital also contracted the virus.
On August 8, the WHO declared the outbreak a “Public Health Emergency of International Concern,” which raised attention and increased resource commitment to affected areas. Just a few days before that announcement, two U.S. healthcare workers were evacuated to Emory Hospital in Atlanta for treatment after being infected. Despite much controversy, it was made clear that these two individuals posed no true risk of ongoing infection in the U.S.—a point that will be explained and emphasized later in the article. About three weeks later they were declared “cured” and released from the hospital, an experience that is already informing more aggressive and targeted treatments for the disease.
Pathogenesis
The Ebola virus is part of the Filoviridae family, which has a long, monofilament structure. Viruses attack cells by binding a receptor site and fusing with the host cell. It then begins making its own proteins within the cell and eventually replicates itself multiple times. Ultimately the newly created viruses exit the host cell by “budding off,” newly coated in the host membrane and leaving the original host cell for dead. Ebola attacks many groups of cells, with a preference toward endothelial cells, immune cells and hepatocytes. The virus will secrete proteins that attack the endothelial cells that line blood vessels, destroying them and creating leaks. In the GI tract similar attacks happen, leading to gastrointestinal distress with vomiting and watery diarrhea. By attacking immune cells, several inflammatory mediators and signals are released into the bloodstream causing a systemic inflammatory response and producing high fevers.
The incubation period is generally 8–10 days but it can vary—as quickly as two days or as long as three weeks have been reported. Initial presentation will typically be flu-like in nature, with headaches, fevers, myalgias, arthralgias and chest pain progressing to confusion and seizures.
As the disease progresses, patients show low platelet counts, and prothrombin (PT) and partial thromboplastin times (PTT) are prolonged. This can lead to a condition known as disseminated intravascular coagulation (DIC), a syndrome where patients lose their ability to clot properly and clinically present with systemic bruising and blood oozing from their eyes, nose and mouth, as well as venipuncture sites. The causes of this dramatic bleeding dysfunction are threefold: physical damage to blood vessel endothelial cells, diminished clotting factor production from liver damage and immune system impairment from the global release of immune modulators. This leads to collapse of the cardiovascular system, multiple organ dysfunction syndrome and then death, which is why the disease can have up to a 90% mortality rate.
Viral Transmission
To date there is still no definitive finding of what animal is the carrier, or “natural reservoir” for this virus, although there is wide speculation it is the fruit bat. Transmission is through exposure to infected blood and body fluids, which include urine, semen, fecal matter and vomit. Needle-stick transmission has been shown to be the deadliest route of transmission. In 1976, the WHO found improper infection control at local African hospitals may have resulted in a faster spread of the disease. It found nurses would receive five syringes each day for their patients, and needles were often only cleaned with warm water before being reused on a different patient. Once proper infection control procedures were implemented there was a containment of the disease in the hospitals.
Non-human studies have shown monkeys may have been infected with aerosol transmission, but there is no empirical data to support that it can be spread airborne from human to human, like in influenza or small pox infections. The study of the disease has shown the infected can be in a close proximity to many people, yet only those who handle their body fluids or care for their remains actually become infected.
It is important to note that, during the incubation period when there are no signs or symptoms, infected people are not contagious. The risk occurs when fever is present, and it becomes more contagious as the symptoms become more serious and viral counts are found to be greater in the blood. This is very mild in comparison to influenza, where transmission can occur one day prior to symptoms, or 7–10 days for small pox.
Infection Precautions
Prior to the 1990s, there was a certain badge of honor that came with having blood on your uniform shirt at the end of tour. The HIV epidemic changed that method of thinking, and in 1987 the CDC published guidelines entitled “Recommendations for Prevention of HIV Transmission in Health-Care Settings,” which stressed the need for physical barrier devices to be worn while handling HIV contaminated body substances.
In 2007, the CDC published guidelines for “isolation precautions,” which lays out a universal approach for patient care and the handling of all body substances. The goal is to create a barrier of protection, not only to prevent the healthcare provider from becoming infected, but also to prevent transmission of a disease by said healthcare worker to other patients.
In the past, it was the practice to wear gloves only if there was potential risk of the patient being infected with HIV or another known bloodborne pathogen. Now, there can be no exceptions, if only because having barrier protection prevents the spread of disease. Questions to reflect upon: Do you wash your hands after every patient contact? Do you limit your use of alcohol-based gels to only as a last resort? How often do you clean your equipment, especially blood pressure cuffs, pulse oximeter probes and anything else that touched the patient? If medically able, have you gotten your annual flu vaccine? If unvaccinated, the infection risk increases and you could still work while contagious, spreading the virus to your patients.
Patient Assessment and Effective Management
As a medical professional, you practice a systematic approach to every call. This should include response, arrival on scene, initial patient contact, interview, diagnostic testing and treatment, concluding with transportation to the hospital and handoff of care. This sound structure can defend you against almost any possible scenario. Maintaining a practice of always donning gloves before touching a patient affords skin contact protection, but there needs to be more diligence. Always wear eye protection while managing the airway with a bag valve mask or during intubation where there is a high risk of droplet transmission to the eyes.
On August 26, 2014, the Centers for Disease Control (CDC) published an interim guideline for all first responders on how to recognize and effectively manage patients who may be infected with the Ebola virus. The recommendations start with call screening by dispatchers, where questions should be asked about symptoms such as vomiting, diarrhea or sudden bleeding with patients complaining of fevers. In addition, call receivers should inquire if these patients have recently travelled from areas where the outbreak has occurred, namely the Western African countries of Guinea, Liberia, Nigeria and Sierra Leone. If the patient is calling from an airport, cruise ship terminal or other international port of entry, that location’s CDC quarantine station needs to be notified immediately. All assigned first responders need to be made aware confidentially of any suspected cases while en route to the assignment.
Effective use of personal protective equipment (PPE) includes donning before entering the location of a suspected case. PPE includes gloves, fluid-resistant gown, N-95 facemask and eye protection. Before making initial contact, ensure this is the best level of protection; you may need additional measures, such as shoe or leg coverings if there is blood or vomitus visible. You should attempt to keep the patient isolated; this means asking family members or other bystanders to leave the patient alone during treatment. Assess for signs of high fever—greater than 38.6 degrees Celsius or 101.5 degrees Fahrenheit. Look for symptoms such as severe headache, nausea, vomiting, diffuse abdominal pains, muscle cramps or sudden unexplained bleeding with no recent trauma. Find out if the patient has recently travelled, or has been in contact with someone who has just returned from the affected countries where the outbreak has occurred.
If after assessment you believe there is a risk of Ebola, notification to the receiving facility should be made in a timely manner to allow for isolation procedures to be established in readiness of receiving the patient. Be cautious of any invasive treatments performed, such as IV insertion or needle injections. The CDC recommends these techniques should not be performed in the back of a moving ambulance. If endotracheal intubation needs to be performed for effective airway management, the CDC recommends you wear both eye protection and an N95 mask while performing a laryngoscopy.
PPE is to be worn at all times until there is no risk of further patient contact. Remove all PPE cautiously, making sure to not have splash contact to the eyes or mucous membranes. Discard all materials in biohazard bags and place in a secured location. Hand hygiene must be immediately performed, with washing being the most effective means. Disinfection of equipment must be performed while wearing a new set of PPE, which includes eye and mouth protection against any splashes that may occur.
Ambulance disinfection should be accomplished with PPE that includes leg and boot coverings. The CDC recommends use of disinfectant that kills “non-enveloped” viruses, such as rotavirus or norovirus. An alternative to this would be a freshly prepared 1:50 bleach solution in a spray bottle. Again, since there is a risk for splash droplets, the CDC recommends face and eye protection while performing disinfection procedures. EMS agencies are encouraged to develop exposure plans for Ebola; this should include notification to the Designated Officer of any patients who are at risk or have been positively identified through laboratory analysis of having the virus. If you feel that you may have come in direct contact with body fluids, such as blood, feces or vomitus, or that during decontamination you may have had splash contact into exposed mucous membranes, notify your supervisor immediately.
Currently, there is no cure for the Ebola virus. Treatment has included receiving plasma from patients who survived the virus with limited success, but recently a vaccine has shown promise. The National Institute of Health (NIH) will begin human trials on the investigational NIAID/GSK Ebola vaccine. The drug introduces only the genetic material of the Ebola virus, so there is zero risk of infection. The hope is the immune system will develop antibodies that will destroy those genes, and then be entered into the body’s immune system “database” so that, if there is an exposure to the actual virus, the body will recognize and destroy it early and effectively. The results of this ongoing study should be published by the end of the year.
Conclusion
Ebola is a virulent and deadly pathogen. We need to respect it, not fear it. Knowledge is the key. Early detection through patient interview and physical exam with necessary barrier protection is vital for all patient contacts.
As healthcare providers, we need to be the voice of reason and assist the community at large in understanding the difference between rational concerns and unsubstantiated rumors. The consensus of the global medical community is that the odds of an Ebola virus outbreak in this country is near zero, and this is primarily due to the way we protect ourselves with proper body substance isolation while conducting both routine patient care and managing critical patients. Having the ability to effectively recognize, manage and contain the virus will allow us to combat and suppress the current health emergency and stave off any potential future outbreaks not only in this country, but the world as well.
References
CDC. Interim Guidance for Managing Patients with Suspected Viral Hemorrhagic Fever in U.S. Hospitals, www.cdc.gov/HAI/pdfs/bbp/VHFinterimGuidance05_19_05.pdf.
CDC. HAN 368: CDC Ebola Response Update #4, https://emergency.cdc.gov/han/han00368.asp.
CDC. Interim Guidance for Emergency Medical Services (EMS) Systems and 9-1-1 Public Safety Answering Points (PSAPs) for Management of Patients with Known or Suspected Ebola Virus Disease in the United States, www.cdc.gov/vhf/ebola/hcp/interim-guidance-emergency-medical-services-systems-911-public-safety-answering-points-management-patients-known-suspected-united-states.html.
National Institutes of Health. NIH to Launch Human Safety Study of Ebola Vaccine Candidate, www.niaid.nih.gov/news/newsreleases/2014/Pages/EbolaVaxCandidate.aspx.
Waterman T. Tara’s Ebola Site, https://web.stanford.edu/group/virus/filo/filo.html.
World Health Organization. Ebola haemorrhagic fever in Zaire, 1976, https://whqlibdoc.who.int/bulletin/1978/Vol56-No2/bulletin_1978_56%282%29_271-293.pdf.
World Health Organization. Ebola in West Africa: looking back, moving forward, https://www.who.int/csr/disease/ebola/en/.
John Bray, MS, NRP, CCEMTP, is adjunct faculty at Saint John’s University in Queens, NY. He is the former director of Saint Vincent’s Hospital–Manhattan Institute of Emergency Care and director of EMS and emergency preparedness at New York Downtown Hospital. Contact him at brayj@stjohns.edu.
Sean M. Kivlehan, MD, MPH, NREMT-P, is the emergency medicine chief resident at the University of California San Francisco and a former New York City paramedic for 10 years. Contact him at sean.kivlehan@gmail.com.