Ebola: Facts, Fiction and Public Health
Poverty, climate change are driving forces behind the deadly epidemic
By Vishnu V. Chundi, MD
Ebola virus disease creates panic worldwide because of its high mortality and randomness. The rapid onset of illness to the time of death can be just a few days. The current epidemic, the 25th of its kind, is unprecedented in terms of case numbers and total deaths. While many factors make it the deadliest epidemic to date, experts agree that poverty is the driving force. Unlike previous outbreaks, which were centered in the Democratic Republic of Congo, the current one arose in West Africa and is caused by the Zaire species of the virus, one of five known subtypes. Ebola is a RNA virus from the Filovirus family.
Tracing the Epidemic
Fruit bats are likely the natural reservoir of the Ebola virus. Monkeys, gorillas, and other animals eat the fruit after it drops to the ground. When these animals are slaughtered and processed for bushmeat, the virus passes on to humans. Habitat loss due to deforestation and the resulting higher density of forest dwelling animals bring the virus into close and regular contact with people. The ongoing economic and demographic changes in Africa, from a village-based agrarian society to an early industrial society with urban population centers, have helped to spread the virus.
Ebola’s incubation period is 2 to 21 days. People are infectious only when symptomatic, developing a gastroenteritis-like illness, with vomiting and diarrhea, and the loss of up to five liters of fluid a day. People succumb mostly from electrolyte imbalances, dehydration and shock. The virus directly affects adrenal glands as well as the liver, causing major hepatic necrosis that leads to disseminated intravascular coagulation. Local African burial rituals of touching the victim’s body before the funeral is thought to contribute to the virus’ spread. Family members as well as health care workers become infected when they touch body secretions. Ebola is not spread through the air.
Without aggressive intervention, the current epidemic could affect millions. Official death toll estimates are well over 5,000, but fatalities are likely under-reported. As in past epidemics, death rates range from 40% to 60%.
Sierra Leone, Liberia, and Guinea are among Africa’s poorest countries, without functioning health care systems. Only 15 Ebola treatment centers are in current operation though plans are underway to open 41 additional centers. These new facilities and improved infection control practices could go a long way toward controlling the epidemic. Local Ebola outbreaks in Nigeria, and other neighboring countries, were well-controlled with tried and true measures of contact tracing and quarantine. The countries are now Ebola-free.
Testing is very sensitive and even if the initial test is negative, repeat testing will be positive within three days of symptom onset. An initial negative test result in some patients is thought to be due to low levels of virus. Early treatment seems to improve survival, but treatment is merely supportive. Experimental treatment with serum and antibodies is underway. Vaccine trials are in the early stages and have thus far been shown to protect a very small number of patients.
Challenges for the U.S.
For the first time, the Ebola virus has reached the developed world. The spread to U.S. and Spanish health care workers is likely due to advanced interventions that resulted in high-risk exposure without appropriate personal protective equipment (PPE).
In the United States, where there have been 10 cases with two deaths, regional referral centers have been established to triage patients. Suspected cases in Chicago (identified through travel and contact history) are sent to Rush University Medical Center, Northwestern Memorial Hospital, the University of Chicago, or Lurie Children’s Hospital for testing and stabilization. Confirmed cases are sent to national centers at the National Institutes of Health, Emory University Hospital, or the Nebraska Medical Center in Omaha, for therapy.
Treatment costs for two patients in Nebraska—at over $1.1 million—was mostly due to the number of personnel involved. Ironically, though early deficiencies in training and practice have been corrected, the surge in U.S. hospitals acquiring PPE led to equipment shortages in Africa. Constant training and investment are needed to protect U.S. health care workers. But a state of readiness is difficult to maintain, and fatigue has already set in. Meanwhile, New York and other states have enacted laws based on public perception rather than sound scientific principles.
As CDC personnel and volunteers in Africa work with local organizations there to bring this deadly disease under control, we should commend these brave and altruistic individuals. They deal with stigma, the fear of contracting Ebola, and risk unneeded quarantine. Let’s celebrate rather than vilify them as threats to our nation.
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