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Understanding Ebola: A Visual Guide

Understanding Ebola: A Visual Guide by Xinyu Liu and Juhan Sonin • Involution Studios Version 1, 10 October 2014, Licensed under Creative Commons Attribution v3 The 2014 Ebola outbreak is the most severe outbreak of Ebola Virus Disease (EVD) since the discovery of ebolaviruses in 1976. As of 8 October 2014, the WHO, CDC and local govern- ments together have reported a worldwide total of 8,034 suspected cases and 3,866 deaths (4,462 cases and 2,330 deaths having been laboratory confirmed). Many experts believe that the official numbers substantially understate the size of the outbreak, due in part to community resistance to reporting cases, and a lack of personnel and equipment to investigate reports of the disease.1 Ebola Cases by Year EVD, formerly called Ebola hemorrhagic fever, was first identified in 1976 with two simultaneous outbreaks in Sudan (South Sudan) and Zaire (now the Democratic Republic of the Congo).2 Nzara - South Sudan What is now South Sudan saw the world's first known outbreak of EVD (Ebola-Sudan). More than 284 people were infected. 3 MORTALITY RATE: 53% Yambuku - People's Democratic Republic of Congo EVD cases (Ebola-Zaire) also emerged from Yambuku, infecting 318 people, 3 MORTALITY RATE: • 88% "The Yambuku outbreak was in a village situated near the Ebola River, from which the disease takes its name 2 Ebola is caused by infection with a virus of the family Filoviridae, genus Ebolavirus. Five subtypes have been identified: Zaire, Sudan, Bundibugyo, Ivory Coast(Taï Forest), and Reston. Reston Ebola virus infects only non-human primates. Average Fatality Rate 5 Ebola Strains Zaire 79% 54% 27% 0% Sudan Bundibugyo Ivory Coast Zaire Strain Sudan Strain Bundibugyo Ivory Coast Tai Forest Reston Seven countries have confirmed cases of the Ebola virus worldwide (five countries in West Africa). Fruit bats, a delicacy for some West Africans, are considered to be virus's natural host. The illustration below describes Ebola cases between 1976 and 2014, with the number of deaths and infections: 284 151 10 1976 1977 Sudan Occurred in Nzara, Maridi and the surrounding area. Disease Zaire England Zaire Occurred in Yambuku and surround- Laboratory infection by Noted retroepec- ing area. Disease was spread by close personal contact and by use of contaminated noodies and syringes in accidental stick of contami- tively in the village nated needle. was spread mainly through close personal contact within of Tandala. hospitals/clinics This outbreak was hospitals. Many medical care personnel were infected. the first recognition of the disease There were no recorded Ebola outbreaks between 1980 -1990. Scientists believe the 34 22 1990 reemergence of the virus is 1979 due to an increase in gorilla and chimpanzee mortality, Philippines USA Sudan increased hunting of fruit bats High mortality among cynomol- Ebola-Reston virus was intro- Occured in Nzara. Maridi. Recur- gus macaques in a primate facility responsible for exporting animals in the USA duced once again into quaran tine tacilities in Virginia, and rent outbreak at the same site as the 1976 Sudan epidemic Texas by monkeys imported from Three workers in the animal the Philippines Four humans tacility developed antibodies but did not get sick developed antibodies but did not get sick. 315 250 52 31 1994 1995 Gabon Ivory Coast Scientist became ill after Democratic Republic of Occured in Mékouka and other the Congo (formerly Zaire) gokd-mining camps deep in the conducting an autopsy on a Occured in Kikwit and surrounding rain forest. Initially thought to be wild chimpanzee in the Tai area. Traced to index case-patient who worked in forest adjoining the city. Epidemic spread through families and hospitals. yellow fever, identified as Ebola Forest. The patient was treat- hemorhagic fever in 1995. ed in Switzeriand. The virus' mutation into new strains - Ivory Coast. 62 46 37 21 11 1997 1996 South Africa Gabon Russia Gabon Occured in Mayibout area. A chimpanzee found dead in the Occurred in Booue area with Laboratory contamination A medical protessional traveled from Gabon to Johannesburg. South Africa, after having treated transport of patients to Libreville Ebola virus-infected patients and thus having beon exposed to the Index case-patient was a hunter who lived in a forest camo. forest was eaten by people hunting for food. Nineteen people who were involved in Disease was spread by close contact with infected persons the butchery of the animal became il; other cases virus, He was hospitalized, and a nurse who took care of him became infected and died. CCcured in family members. 425 224 122 96 2000 2001 2002 Oct Gabon, Republic of Congo Uganda Occurred in Gulu, Masindi, and Mbarara districts of Uganda. The three most important Outbreak occured over the border of Gabon and the Republic of the Congo. This was the first time that Ebola hemorrhagic fever was reported in the Republic of the Congo. risks associated with Ebola virus infection were attending funerals of Ebola hemorhagic fever case-patients, having contact with case-pa- tients in one's family, and providing medical care to Ebola case-patients without using adequate personal protective measures 143 128 35 29 2003 Republic of Congo Republic of Congo Outbreak occured in Mbomo and Outbreak occurred in the districts of Mbomo and Kelé in Cuvette Ouest Mbandza villages located in Mbomo distric, Cuvette Ouest Département. Départemet. 264 187 177 2004 2007 Sudan Russia Republic of Congo Outbreak occured in Yambio Laboratory contamination Outbreak occured in Kasai Occi- county of southern Sudan. This dental Province. The outbreak was outbreak was concurrent with an declared over November 20. Last outbreak of measles in the same confirmed case on October 4 and area, and several suspected EHF cases were later reclassi- last death on October 10 fied as measeles cases 149 37 32 15 2009 2008 Republic of Congo Philippines Uganda Outbreak occurred in Bundibugyo Outbreak occurred in the Mweka and luebo health zones of the Prov- ince of Kasai Occidental First known occurrence of Ebo- la-Reston in pigs. Strain closely District in westem Uganda. The similar to earlier strains. Six workers virus' mutation into new strains from the pig farm and slaughter- - Bundibugyo. house developed antibodies but did not become sick 11 2011 2012 Jun| Oct Uganda Uganda The Ugandan Ministry of Health informed the Outbreak occurred in the Kibaale public that a patient with suspected Ebola Hemor- rhagic fever died on May 6, 2011 in the Luwero District of Uganda. Laboratory tests of blood samples were conducted by the district, Uganda. The quick diagnosis from a blood UVRI and the U.S. Centers for Disease sample of Ebola virus was provided by the new CDC Viral Hemorrhagic Fever laboratory installed at the Uganda Viral Research Institute (UVR). Control and Prevention (CDC). 63 36 13 2013 Nov Uganda Republic of the Congo Outbreak occurred in the Luwero District Cutbreak occurrd in DRC's Province Orientale. Laboratory support was provided through CDC and the Public Health Agency of Canada (PHAC)'s field laboratory in Isiro, and through the CDCUVRI lab in CDC assisted the Ministry of Health in the epidemiclogic and diagnostic aspects of the outbreak. Testing of samples by CDC's Viral Special Pathogens Branch occurred Uganda. The outbreak in DRC has no epidemiologic link to the near contemporanecus Ebola cutbreak in the Kibaale district of Uganda. at UVRI in Entebbe. 8034 3866 There has been a sharp rise in cases in the first half of August. This graph illustrates the increase over time of cases and deaths during the 2014 outbreak: 8 7492 3439 The outbreak began in March, with the first case reported in Guinea. Since then the numbers of cases and deaths have risen at an alarming rate. **On 8th August 2014, the WHO declared an international emergency in relation to the Ebola outbreak, with officials reporting that a coordinated response would be essential to stop and reverse the spread of the virus. The numbers of cases and deaths have been listed for the biggest out- breaks Some experts predict that if we don't get control of the virus, the number of infections could mushroom to nearly 55,000 cases by November 2014. 3069 1752 1323 729 390 270 281 186 221 146 112 70 2014 Apr May The Ebola outbreak in Guinea Madrid, Spain Liberia, and Sierra Leone is the first Suspected and confirmed case count: 1 Suspected and confirmed case deaths: 0 in West Africa since 1994, when a scientist contracted the disease while working with infected chimpanzees. The scientist had the Ivory Coast strain and eventually recoverd. 10 MORTALITY RATE: 0% Senegal Suspected and confirmed case count: 1 Guinea, Sierra Leone, Liberia and Suspected and confirmed case deaths: 0 Nigeria are the four main counties involved in the 2014 outbreak: MORTALITY RATE: 0% Guinea Suspected and confirmed case count: 1,298 Suspected and confirmed case deaths: 768 MORTALITY RATE: 60% Sierra Leone Suspected and confirmed case count: 2,789 Suspected and confirmed case deaths: 879 MORTALITY RATE: 27% Democratic Republic of the Congo Suspected and confirmed case count: 70 Suspected and confirmed case deaths: 43 MORTALITY RATE: • 61% *This outbreak is unrelated to the current outbreak of Ebola in West Africa. Nigeria Suspected and confirmed case count: 20 Suspected and confirmed case deaths: 8 MORTALITY RATE: 40% Liberia Suspected and confirmed case count: 3,924 Suspected and confirmed case deaths: 2,210 MORTALITY RATE: 54% Dallas, TX, US Home range of Pteropodidae family of fruit bat 1 Suspected and confirmed case count: 1 Suspected and confirmed case deaths: 1 Country reported EVD outbreaks Country reported travel-associated Ebola case in human MORTALITY RATE: • 100% Virus Transmission Ebola is introduced into the human population through contact with an infected animal. Ebola is spread through close and direct physical contact with infected bodily fluids, the most infectious being blood, faeces and vomit. The Ebola virus has also been detected in breast milk, urine and semen. In Africa, infection has been documented through the handling of the following infected ani- mals found ill or dead in the rainforest: 12 Chimpanzees Gorillas Fruit Bats Monkeys Forest Antelope Porcupines Ebola then spreads in the community through human-to-human transmission, with infection resulting from direct contact (through broken skin or mucous membrane) with the blood, secretions, or other bodily fluids, or with the organs of infected people, and indirect contact with environments contaminated with such fluids.13 The following are the most common methods of EVD transmission between people: Contact with infected stool or Contact with Contact with Contact with an infected dead Contact with infected medi- Contact with Unprotected sex with an infected infected blood infected breast saliva / sweat urine milk body cal items infected person Symptoms of Infection Ebola is a severe acute viral illness often characterized by the sudden onset of fever, intense weakness, joint and muscle pain, sore throat and headache. These symptoms are then followed by more severe complications, along with decreased function of the liver and kidneys. Around this time, affected people may begin to bleed both within the body and ex- ternally. The incubation period is 2 to 21 days. Humans are not infectious until they develop symptoms. The full list of potential symptoms includes:14 15 16 Headache (40% - 90%) Fever (90% - 100%) Sore Throat (63%) Red Eyes Cough Difficulty Swallowing Difficulty Breathing Chest Pain Joint and Muscle Pain Skin Rash (5% - 20%) Diarrhoea (81%) Stomach Pain (60% - 80%) Lack of Appetite Vomiting (59%) Internal and External Bleeding Feeling of Weakness |Symptom presents in most patients Symptom may appear in some patients Early stages of infection Later stages of infection Diagnosis and Treatment Ebola diagnosis requires ruling out other diseases, which may include malaria, typhoid fever, shigellosis, cholera, leptospirosis, plague, rickettsiosis, relapsing fever, meningitis, hepatitis, and other viral hemorrhagic fevers. Once these have been ruled out, Ebola virus infections can be diagnosed definitively in a laboratory through several types of tests:" • Antibody-capture enzyme-linked immunosorbent assay (ELISA) • Antigen-capture detection tests • Serum neutralisation test • Reverse transcriptase polymerase chain reaction (RT-PCR) assay • Electron microscopy • Virus isolation by cell culture To confirm the diagnosis, blood test samples are tested for viral antibodies, viral RNA, or the virus itself. There is no licensed vaccine or specific treatment available for Ebola. A range of po- tential treatments including blood products, immune therapies, and drug therapies are cur- rently being tested, but none are availble for clinical use. Tests of new Ebola drugs could take place as early as November 2014.19 The lack of vaccines or specific treatments is part of what makes the mortality rate so high. The death rate from Ebola ranging from 25% to 90%, depending on the strain, but the cur- rent outbreak has a mortality rate of about 70%(as of 23 September 2014). 19 The course of treatment for infected patients involves supportive care: providing relief of symptoms while the body fights the infection. Intravenous fluids, antibiotics, and oxygen are usually employed. Treatment may also include the use of medications to control fever, help the blood clot, and maintain blood pressure. Even with such supportive care, death occurs in 50 to 90 percent of cases. • Intravenous (IV) fluids to maintain fluids and electrolytes (sodium, potassium, and chloride) • Oxygen and devices that help with breathing • Medications to control fever, help the blood clot, and maintain blood pressure • Antibiotics to prevent secondary infections from bacteria • Good nursing care. Current bed capacity for patients in countries with active cases as at end of 21 Sep 2014 20 Existing Bed Capacity Beds to be set-up by an identified partner Additional beds needed without a partner identified Guinea Liberia Sierra Leone 0 100 200 500 1000 1500 2000 • ZMapp, a monoclonal antibody vaccine. The limited supply of the drug has been used to treat a small number of individuals infected with the Ebola virus. Although some of these have recovered the outcome is not considered statistically significant. ZMapp has proved highly effective in a trial involving rhesus macaque monkeys. TKM-Ebola, an RNA interference drug. • Favipiravir, a drug approved in Japan for stockpiling against influenza pandemics. The drug appears to be useful in a mouse model of the disease and Japan has offered to supply the drug if requested by the WHO. In September, an experimental vaccine, currently known as the NIAID/GSK vaccine, com- menced simultaneous Phase 1 trials in Oxford and Bethesda. The vaccine was developed jointly by GlaxoSmithKline and the NIH. If this phase is completed successfully, the vaccine will be fast tracked for use in West Africa. In preparation for this, GSK is preparing a stockpile of 10,000 doses.21 Prevention and Control Good outbreak control relies on a coordinated set of interventions including case man- agement, surveillance and contact tracing, reliable laboratory services, safe burials, and social mobilization. Community engagement is key to successfully controlling outbreaks. Raising awareness of risk factors for Ebola infection and protective measures that individ- uals can take is an effective way to reduce human transmission. Risk reduction messag- ing should focus on several factors: Avoid physical contact with people showing symptoms of the Ebola virus. Wash your hands regularly with clean water and soap. Keep away from fruit bats, monkeys, dead animals, and bush meat. Inform health authorities Thoroughly cook all animal products before consump- Travel to areas where there is immediatly in case of con- tact with expected or con- firmed Ebola case. an Ebola outbreak only in case of urgent need. tion. Contact tracing involves finding everyone who comes in direct contact with a sick Ebola patient. Contacts are watched for signs of illness for 21 days from the last day they came in contact with the Ebola patient. If the contact develops a fever or other Ebola symp- toms, he or she is immediately isolated, tested, treated, and the cycle starts again-all of the new patient's contacts are found and watched for 21 days, and so on. Potential of Spreading Internationally There are major concerns that the EVD outbreak could spread, particularly to Europe and the United States. The main concern centres around air travel, which is thought to the primary potential route for the virus to spread across international and continential borders. Air traffic connections from West Africa to the rest of the world. While Guinea, Liberia and Sierra Leone don't have many flights outside the region, Nigeria is well-connected to Europe and the U.S.2 Top passenger flows: Number of passengers(weekly) 6000+ 3000-6000 CANADA 1500-3000 300-1500 MOROCCO CHNA dhoins CAMER KENA Below are the final destinations of airline travelers departing from Guinea, Liberia and Sierra Leone in the month of August 2014 (source: WHO):23 W. Pacific S.E. Asia E. Med 6.5% Americas Europe 29.6% Africa 4.5% 3.1% 1.1% 55.2% The figures show that travel from Sierra Leone, Guinea, and Liberia within the conti- nent of Africa is much more prevalent than travel elsewhere. This data, coupled with the fact that outbreaks persist in countries with poor sanitation and a shortage of resources to contain them (rather than resource-rich places like the US and the UK), leaves public health officials relatively unconcerned about Ebola becoming a big problem in the developed world. Far more concerning is the potential for the disease spreading within Africa, which is what public health officials are really worried about. Designed by Xinyu Liu and Juhan Sonin Pinvolutionstudos

Understanding Ebola: A Visual Guide

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A comprehensive visual explanation of the 2014 Ebola outbreak


Juhan Sonin


Xinyu Liu


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