Welcome back. Let's talk about Ebola virus disease. The first filovirus to be discovered, was called the Marburg virus, pictured here. It was named after the site of one of the outbreaks in Marburg, Germany. 31 individuals developed hemorrhagic fevers as a result of infection from this virus. In 1975, a traveler likely infected in Zimbabwe, came down with the Marburg virus infection in Johannesburg, South Africa. Secondary cases developed, including a nurse and a traveling companion. The Ebola virus was discovered in 1976 by Dr. Peter Piot, a Belgian clinical microbiologist. It was named after the Ebola river in Zaire. Zaire has subsequently been renamed the Democratic Republic of Congo. He had received a vial of blood from a doctor taking care of a nun. The Belgian doctor was based in Yambuku, Zaire. The nun subsequently died. Dr. Peter Piot examined the virus under an electron microscope and saw a gigantic worm-like structure that resembled the Marburg virus. Two weeks later, he flew to Zaire to investigate the outbreak. What are some of the characteristics of the Ebola virus? Well, it belongs to the Filoviridae family, and that is in reference to its filamentous nature. It's a single-stranded RNA virus, and there's three genera of filoviruses. Cuevavirus, marburgvirus, and Ebola virus. There have been six species of Ebola virus identified so far, and that includes Ebola, Sudan, Tai Forest, Bundibugyo, Reston, and Bombali. Of the six species, only four are known to cause disease in humans, and that includes Ebola, Sudan, Tai Forest, and Bundibugyo. The rest of the virus causes disease in non-human primates, but fortunately not in humans. The 2014 outbreak, was the largest identified at that time. That included three countries. Sierra Leone, Guinea, and Liberia. Thanks to air travel, Ebola can spread around the world. There are many signs and symptoms of the Ebola virus disease, including hiccups, red eyes, internal bleeding, severe profuse diarrhea, and a rash. It's not known which is the host animal for the Ebola virus, but it is believed that the reservoir is probably a bat. The Bombali virus, which was most recently discovered, was in fact identified in free-tailed bats, which is identified here. Scientists have long suspected that bats are the host animal for the Ebola virus, but identifying it in them has been extremely difficult. The Ebola virus is a zoonotic disease, it's ecology again, is believed to be in bats infecting a number of different animals, including humans. Bushmeat consumption, is a risk factor for acquiring Ebola. Consuming wild animals such as bats, monkeys, or apes, can increase the risk of viral transmission of the Ebola virus. However, the need for food security and the increasing demand for animal proteins, increases the risk for zoonotic diseases, and these are critical global public health issues. Illegal poaching of endangered animals is a serious problem. One of the challenges of containing an outbreak such as Ebola, is figuring out how long to put people into quarantine. 95 percent of the confirmed Ebola virus cases, had incubation periods ranging from 1-21 days. The incubation period is the time between exposure to the pathogen or microbe and the time to develop the disease. Since most of the patients develop it within 21 days, the CDC recommends a 21 day quarantine. Index patients usually have contact with a wild animals such as a bat or a monkey, and the virus can also spread through direct contact with blood or other bodily fluids. The people who are at the highest risks, are health care and mortuary workers. There are a number of antiviral medications under study, as of 2019 though, there are no approved FDA antiviral medications against Ebola. These drugs would have to interfere with the viruses ability to replicate itself. There are a number of experimental medications that have been used in subsequent Ebola outbreaks. Unfortunately, as of 2019, there are no FDA approved vaccines against Ebola. There are a number of experimental Ebola vaccines under study, including a vaccine studied by Dr. Ana Maria Henao-Restrepo and colleagues, using a modified vesicular stomatitis virus vaccine. Supportive care to treat patients with Ebola virus disease is absolutely essential. People with Ebola, suffer from severe losses of bodily fluids, including profuse diarrhea and vomiting, and they can become rapidly dehydrated. Rehydration therapy, preferably oral, but if necessary intravenous, and balancing electrolytes or the body salts, are critical for maintaining blood pressure. The patients require intensive nursing care. Let's look at the West African Ebola crisis from 2014-2016. All three countries, Guinea, Liberia, and Sierra Leone, had been suffering from years of war, government corruption, and extreme poverty. There was widespread deforestation in the region, destroying habitats. Ebola had never struck these countries before, which contributed to a delay in diagnosis. Unfortunately, by the time Ebola was discovered, it had already spread far and wide. None of the countries had functioning medical or public health infrastructures capable of handling routine illnesses, let alone a deadly diseases like Ebola. There were other factors that hindered disease containment. Burial practices involving bathing and touching departed loved ones, facilitated disease spread. Widespread public denial, panic, mistrust, hurt quarantine, and isolation efforts. This is a picture of angry Liberians throwing rocks at policemen who are trying to enforce quarantine to curb the outbreak. The number of Ebola cases by countries skyrocketed. This is the total number of cases reported. So the total number of Ebola cases was over 28,000, over 15,000 laboratory confirmed, and over 11,000 deaths. Leadership during an Ebola crisis is very difficult. President Alpha Conde, who was President of Guinea, was the first democratically elected leader in Guinea. He inherited multiple corruption scandals and even survived an assassination attempt. Despite his difficulties, Guinea had the fewest number of Ebola cases and deaths of the three countries affected. In Liberia, Ellen Johnson Sirleaf was the president. She was the first female head of state elected in Africa. She was credited with bringing peace to the country after a 14-year civil war. For her efforts to end the war, she was awarded the Nobel Peace Prize in 2011. The Ebola outbreak severely tested her leadership skills. She had ordered quarantine of one of Monrovia's largest slums, and that backfired as protestors responded with violence. Liberia had the most Ebola deaths of the three nations. In Sierra Leone, the President was Ernest Bai Koroma. Koroma had been slowly improving the country's infrastructure when Ebola erupted. In July of 2014, he launched a national response plan and declared a state of emergency. The country suffered a major loss when its chief virologists, Dr. Sheik Humarr Khan, died from Ebola. He was only 39 years old. In contrast to President Sirleaf in Liberia, who isolated a single slum for quarantine, President Koroma sequestered the entire population of Sierra Leone for three days, so that healthcare workers could go from home to home educating people about Ebola. Dr. Margaret Chan, who had responded to the avian influenza outbreak in Hong Kong, was in charge of the World Health Organization during the Ebola crisis. She was criticized for waiting four and half months before declaring a global emergency of the Ebola outbreak in West African. Severe budget cuts to the World Health Organization hobbled its efforts to respond to the Ebola outbreak. As a result, the agency was severely criticized for its poor handling of the crisis. In 2017, as a result of its criticism, the World Health Organization issued an emergency response framework to clarify the roles and responsibilities of emergency responders to outbreaks. This report specified that the World Health Organization's role in such outbreaks, is primarily advisory and supportive, it does not replace or take over the affected countries infrastructures. This is similar to the CDC's role in the United States where public health responsibility, is centered around state and local governments, not the federal government. So the questions for this section are, describe Ebola virus ecology. What is believed to be the host animal? During the 2014, 2016 West African Ebola outbreak, what factors hindered containment strategies? Residents in a Liberian slum rioted and protested to President Sirleaf's quarantine order, but there were no reports of rioting when President Koroma sequestered the entire population. Why might the residents in one country riot while others in another country did not during disease containment efforts? What is the World Health Organization's role during a pandemic? Do you think the criticism of the World Health Organization's response to the Ebola crisis was justified? Why or why not? Finally, what might a One Health approach to the Ebola virus encompass? I would like to thank you for your time and attention over these past six weeks in learning about an introduction to One Health Policy. This was an interdisciplinary course integrating One Health, human, animal, and environmental health with policy, with politics, and with science. I look forward to your participation in the questions and discussion sections. Thank you very much.
