Now Available, By Alex Smith –
Understanding and Preparing for an Outbreak
The 2014 West African Ebola Outbreak has spread into Europe and the United States.
The WHO admits that this crisis will get much worse before it gets better.
Are you prepared for an outbreak?
What should you do to prepare?
Ebola: Understanding and Preparing for an Outbreak, addresses these, and many more questions.
Written in a clear and concise manner, with the reader that has beginning or intermediate knowledge of the Ebola Virus and disaster preparedness in mind, this book explores the following topics:
Chapter 1: Introduction and Glossary of Terms
Chapter 2: About Ebola (Transmission, Symptoms, Treatment)
Chapter 3: The History of Ebola
Chapter 4: The 2014 West African Ebola Outbreak
Chapter 5: Early Stage – What to do Now
Chapter 6: Advanced Stage – Outbreaks in Your Country/Region
Chapter 7: Crisis Stage – An Epidemic in Your Area
Chapter 8: Methods of Disinfection
Chapter 9: Establishing Safe Practices (Isolation Rooms, Quarantine Areas, Cleaning Spills, etc.)
Chapter 10: Preparations (PPEs and Other Necessary Supplies)
Chapter 2: General Information
Chapter 2 is divided into the following sections:
When does a Person Become Contagious?
The Ebola Virus Disease (EVD) is one of several Viral Hemorrhagic Fevers (VHFs). Symptoms begin 2 to 21 days after exposure. These symptoms can easily be mistaken for other diseases initially, as they are common to everything from the flu to malaria. This allows the virus a period of time for it to be spread before the infected are isolated.
As far as viruses go, Ebola kills its victims very quickly. It has a mortality rate of 25% to 90%, with a historical average of nearly 70%. Death by Ebola is horrific and is usually caused by dehydration or organ failure – specifically the liver and kidneys. While these traits are terrifying, they work against the disease. For a virus to spread, its hosts must be alive to spread it. Because of this, Ebola outbreaks have historically burned out quickly.
There are five known subtypes, or strains, of the Ebola Virus. They are:
- Zaire Ebolavirus (ZEBOV): Discovered in 1976. Most lethal strain.
- Sudan Ebolavirus (SEBOV): Discovered in 1976.
- Ivory Coast Ebolavirus (ICEBOV): Discovered in 1994. There has been only one known infection by ICEBOV. A scientist contracted the virus during the necropsy of an infected chimpanzee. He survived.
- Ebola-Reston (REBOV): Discovered in 1989 in Crab-eating Macaques (monkeys). REBOV is the only strain that is not known to cause infections in humans.
- Bundibugyo Ebolavirus (BEBOV): Discovered in 2007. It is most closely related to the ICEBOV strain.
There are large variations between the strains (approximately 30-40% variation between genome sequencing). Because of this, if a vaccination is developed for one subtype, it may not necessarily work for the others.
Ebola is a virus only occurring in mammals, as best we know. Humans, monkeys, baboons, gorillas, chimps, pigs, dogs, fruit bats and other animals are known to be susceptible to the various strains. Different subtypes have differing effects on the species. In the instance of Reston, humans are asymptomatic, while can be fatal to monkeys. In other strains, fruit bats, dogs and other animals can be asymptomatic, while humans are left susceptible.
Sources conflict, but some believe that the 20 to 30 year-old age group appears to be particularly susceptible. This may be because this age group are the healthiest age group, and are more likely to be caring for the sick. Children would be more likely to be shielded from the disease, whereas their parents would be caring for infected family members.
Rates of genetic change are approximately 100 times slower than Influenza A, or approximately the same magnitude as Hepatitis B. It is not common for viruses to mutate methods of transmission, though it is possible.
Upon infection, Ebola targets the host’s blood coagulative and immune defense systems. The attack on the coagulative system leads to hemorrhaging. The attack on the immune system leads to severe immunosuppression. Symptoms of Ebola may appear anywhere from 2 to 21 days after exposure. The average appearance of symptoms is in 4 to 10 days.
Early symptoms (typically day 5 to 9):
- Severe headache
- Sore muscles
Advanced symptoms (typically day 6 to 10):
- Fever (greater than 38.6°C or 101.5°F)
Critical Symptoms (typically day 7 to 11):
- Brain damage
- Unexplained hemorrhage (bleeding or bruising) from the nose, eyes, mouth, anus, etc.
Final Symptoms (typically day 8 to 12):
- Loss of consciousness
- Massive internal bleeding
Ebola outbreaks are believed to start through a natural reservoir, such as a fruit bat. Other animals may feed on fruit dropped by the bat, or the bats themselves. It is believed that humans are infected through handling and consuming bush meat.
When an infection occurs in a human, Ebola can be spread in several ways. According to the CDC, Ebola is spread through:
- Direct contact: Direct contact (through broken skin or the nose, mouth, or eyes) with blood or other bodily fluids (such as saliva, urine, sweat, semen, breast milk, or feces) of the infected person.
- Animals: Natural reservoirs or carrier animals.
- Objects (fomites) that have been come in contact with the infected person:
Ebola can survive on fomites for various lengths of time, depending on environmental conditions. Laboratory experiments have shown that the virus can survive in infected tissue on surfaces for over 50 days at a temperature of 4oC (-15oF). In other experiments, the virus was able to survive in the dark for hours at temperatures of 20oC (68oF) and 30%-40% relative humidity. The amount of detectable virus was reduced to 37% of the original amount after 15.4 hours.
- Airborne droplets (Not Confirmed by Authorities):
The CDC makes no mention of transmission through airborne droplets in humans. Because of the severity of the current outbreak, however, transmission through airborne droplets seems like a possible explanation. Note that the author says airborne droplets and not simply airborne. There is a huge difference. Airborne implies that a disease can be spread through the inhalation of tiny, dry particles that remained suspended in the air for long a period of time. These particles could also theoretically be transferred through air currents. Ebola is not airborne in this sense. The rate of infection is much too low. If Ebola was truly airborne, it should spread at a rate similar to tuberculosis, chickenpox or measles. One person with measles, on average, infects 12 to 18 people. The current Ebola outbreak appears to spread, on average, to one to two people. This value is known as the Basic Reproductive Number, R0. The following is a chart of the Basic Reproductive Numbers for various diseases.
Airborne droplets, however, is a different story. Airborne droplets are relatively large (when compared to the dry particles that are suspended in the air by an airborne disease), wet particles, propelled through the air by way of coughing, sneezing or violent vomiting, that land on walls, floors, or other people. It is entirely possible that Ebola is spread via airborne droplets. The CDC still denies this. The WHO downplays the probability. Other experts, especially those who are independent of governmental organizations, are not as quick to dismiss this.
Despite CDC claims that droplet transmission is not possible, it has been shown that VHFs have an infectious dose of 1 to 10 organisms by airborne droplets in non-human primates.
- Source: Franz, D. R., Jahrling, P. B., Friedlander, A. M., McClain, D. J., Hoover, D. L., Bryne, W. R., Pavlin, J. A., Christopher, G. W., & Eitzen, E. M. (1997). Clinical recognition and management of patients exposed to biological warfare agents. Jama, 278(5), 399-411.)
Additionally, laboratories have been able to demonstrate that primates exposed to airborne droplets from pigs have become infected.
- Source: Twenhafel, N. A., Mattix, M. E., Johnson, J. C., Robinson, C. G., Pratt, W. D., Cashman, K. A., Wahl-Jensen, V., Terry, C., Olinger, G. G., Hensley, L. E., & Honko, A. N. (2012). Pathology of experimental aerosol Zaire ebolavirus infection in rhesus macaques. Veterinary Pathology Online, 0300985812469636.
- Source: Mwanatambwe, M., Yamada, N., Arai, S., Shimizu-Suganuma, M., Shichinohe, K., & Asano, G. (2001). Ebola hemorrhagic fever (EHF): mechanism of transmission and pathogenicity. Journal of Nippon Medical School.68 (5), 370-375.
- Source: (2004). In R. G. Darling, & J. B. Woods (Eds.), USAMRIID’s Medical Management of Biological Casualties Handbook (5th ed., pp. 40-44). Fort Detrick M.D.: USAMRIID.
- Source: Reed, D. S., Lackemeyer, M. G., Garza, N. L., Sullivan, L. J., & Nichols, D. K. (2011). Aerosol exposure to Zaire ebolavirus in three nonhuman primate species: differences in disease course and clinical pathology. Microbes and Infection, 13(11), 930-936.
- Source: Feigin, R. D. (Ed.). (2004). Textbook of Pediatric Infectious Diseases (5th Ed.). Philadelphia, USA: Elsevier, Inc.
- Aerosol Transmissibles (Not Confirmed by Authorities): According to The Center for Infectious Disease Research and Policy (CIDRAP), “We believe there is scientific and epidemiologic evidence that Ebola virus has the potential to be transmitted via infectious aerosol particles both near and at a distance from infected patients, which means that healthcare workers should be wearing respirators, not facemasks.” They continue, “Modern research, using more sensitive instruments and analytic methods, has shown that aerosols emitted from the respiratory tract contain a wide distribution of particle sizes—including many that are small enough to be inhaled. Thus, both small and large particles will be present near an infectious person. The chance of large droplets reaching the facial mucous membranes is quite small, as the nasal openings are small and shielded by their external and internal structure. Although close contact may permit large-droplet exposure, it also maximizes the possibility of aerosol inhalation. As noted by early aerobiologists, liquid in a spray aerosol, such as that generated during coughing or sneezing, will quickly evaporate, which increases the concentration of small particles in the aerosol. Because evaporation occurs in milliseconds, many of these particles are likely to be found near the infectious person. The current paradigm also assumes that only “small” particles (less than 5 micrometers [mcm]) can be inhaled and deposited in the respiratory tract. This is not true. Particles as large as 100 mcm (and perhaps even larger) can be inhaled into the mouth and nose. Larger particles are deposited in the nasal passages, pharynx, and upper regions of the lungs, while smaller particles are more likely to deposit in the lower, alveolar regions. And for many pathogens, infection is possible regardless of the particle size or deposition site.”
“To summarize, for the following reasons we believe that Ebola could be an opportunistic aerosol-transmissible disease requiring adequate respiratory protection:
- Patients and procedures generate aerosols, and Ebola virus remains viable in aerosols for up to 90 minutes.
- All sizes of aerosol particles are easily inhaled both near to and far from the patient.
- Crowding, limited air exchange, and close interactions with patients all contribute to the probability that healthcare workers will be exposed to high concentrations of very toxic infectious aerosols.
- Ebola targets immune response cells found in all epithelial tissues, including in the respiratory and gastrointestinal system.
- Experimental data support aerosols as a mode of disease transmission in non-human primates.”
The author tends towards CIDRAP’s stance. Infection through Direct Contact is certain, and airborne droplet seems likely, but aerosol transmissibles for up to 90 minutes appears possible as well.
The complete CIDRAP article (with multiple sourced studies) can be found here:
- Viral Shedding (Not Confirmed by Authorities): Researchers have also observed viral shedding from infected pigs via nasopharyngeal (upper portion of the pharynx, from the base of the skull to the roof of the mouth) secretions and rectal swabs.
- Source: Kobinger, G. P., Leung, A., Neufeld, J., Richardson, J. S., Falzarano, D., Smith, G., Tierney, K., Patel, A., & Weingartl, H. M. (2011). Replication, pathogenicity, shedding, and transmission of Zaire ebolavirus in pigs. Journal of Infectious Diseases, jir077.
- Source: Marsh, G. A., Haining, J., Robinson, R., Foord, A., Yamada, M., Barr, J. A., Payne, J., White, J., Yu, M., Bingham, J., Rollin, P. E., Nichol, S. T., Wang, L-F., & Middleton, D. (2011). Ebola Reston virus infection of pigs: clinical significance and transmission potential. Journal of Infectious Diseases, 204(suppl 3), S804-S809.
The author would contend that there are no studies that suggest airborne droplet, aerosolized transmissions and viral shedding in humans is possible because researchers are having a difficult time finding volunteers, with there not being a cure and all.
- Semen: Another means of transmission worth discussing is semen. Studies have suggested that the Ebola Virus may remain transmissible through a survivor’s semen for 70 to over 90 days. Survivors should abstain from sexual contact for at least four months, or until additional research can be performed to determine a more precise period of possible infection.
Once an infected person recovers from Ebola, they can no longer spread it, other than through semen. People who recover develop antibodies that may last for at least 10 years. These antibodies may be critical in the development of a viable treatment for the virus.
There is no evidence that mosquitos or other insects can transmit Ebola. Only mammals have displayed the ability to become infected and spread the virus.
When Does an Infected Person Become Contagious?
Authorities say that a person is only contagious once symptoms are present. This may very well be true. The author believes it is also possible that this strain of Ebola may be contagious before symptoms are present. This is merely conjecture, but may also explain how this outbreak has managed to last far longer than any previous outbreaks. The following is a list of other diseases and when an infected person first becomes contagious:
- Chickenpox: One to two days before a rash appears.
- Common Cold: One to two days before symptoms appear.
- Flu (Influenza): Typically one day before symptoms appear.
- Measles: Not definitively established. Measles is most infectious after the first symptoms appear and before the rash develops.
- Mumps: Approximately six days before swelling of the glands.
- Rubella (German measles): One week before a rash appears.
- Shingles: Infectious from when a rash first appears until the last blister has scabbed over. Typically five and seven days after symptoms start.
Based on the above, many diseases are infectious prior to the onset of symptoms. Furthermore, the period from which measles becomes contagious has not been definitively established. Measles was first isolated in 1954 and has been researched much more extensively than Ebola. How then, are authorities uncertain of measles, yet certain of Ebola?
The author contends that there remains a possibility that Ebola may be contagious prior to the onset of symptoms, especially since it has been shown that VHFs have an infectious dose of 1 to 10 organisms by airborne droplets in non-human primates. The author contends that if a small amount of the virus is present in an infected person’s bodily fluids, then they are potentially contagious.
Diagnosing Ebola can be difficult. Early symptoms are common to many different infections. This period of uncertainty allows an infected person to continue on with their lives, possibly infecting others. In Africa, malaria and typhoid fever exhibit the same symptoms, and are far more common. In the West, early symptoms are similar to the flu.
If someone has the early symptoms of Ebola and has had known contact with an infected individual, or infected areas, they should seek medical assistance immediately. Self-isolation should be practiced until authorities can properly quarantine the person. Samples from the person can then be collected and tests can be performed to confirm infection.
Ebola diagnosis tests include:
- Complete Blood Count (CBC)
- Tests to show whether virus-specific antibodies exist in the patient (ELISA)
- Liver function tests
- Coagulation studies (how well the blood clots)
Currently, no rapid means of diagnosing Ebola exists.
Currently, there is no cure for Ebola. Several experimental treatments and vaccines for the disease are under development, but they have not yet been fully vetted. Their effectiveness and safety is yet to be determined.
Currently, treatment is mostly supportive in nature. Management of pain, maintaining oxygen status and blood pressure, and providing intravenous (IV) fluids and electrolytes can provide some level of comfort and improve the chances of patient survival.
Surviving Ebola is affected by the level of care provided to the patient, as well as their immune system’s response to the disease. An immunocompromised person will have greater difficulty surviving the virus, compared to a healthy individual. Survivors of previous outbreaks have been known to develop vision and joint problems, as well as other long-term complications.
The experimental treatments and vaccines currently being considered for use are as follows:
- Brincidofovir (Treatment): An antiviral drug granted emergency FDA approval for investigative treatment, after being found effective against the virus in in-vitro testing. Brincidofovir was administered to treat Thomas Duncan in Dallas.
- BCX4430 (Treatment): An antiviral drug currently being researched by the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID).
- Favipiravir (Avigan) (Treatment): Approved in Japan for stockpiling against influenza pandemics. The drug shows promise based on animal testing. A clinical trial is being planned for patients in Guinea in November 2014. The French Health ministry has authorized its use.
- TKM-Ebola (Treatment): An RNA interference drug. TKM-Ebola started its Phase 1 trial in early 2014. It has received limited approval from the FDA for emergency use.
- ZMapp (Treatment): A combination of monoclonal antibodies. The drug has been used to treat seven infected individuals infected with the Ebola virus. Some of them have recovered, but the outcome is not considered to be statistically significant. ZMapp has proven highly effective in a trial involving macaques. October 8, 2014, Texas A&M said it was ready to mass-produce the drug, pending final approval.
- cAd3-ZEBOV (Vaccine): Currently in Phase 1 trials. GlaxoSmithKline, a joint developer, is stockpiling 10,000 doses in anticipation of its successful completion.
- rVSV-ZEBOV (Vaccine): Pending Phase 1 trials. Developed by the Public Health Agency of Canada. Mass production is not expected until sometime in 2015.
- The WHO has stated that transfusion of whole blood or purified serum from Ebola survivors is the therapy with the greatest potential to be implemented immediately. This method is currently being studied.
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