EBOLA A
EMERGING THREAT Dr.T.V.Rao MD
Dr.T.V.Rao MD 2
Discovery of EBOLAEbola viruses are found in several African countries. Ebola was first discovered in 1976 near the Ebola River in what is now the Democratic Republic of the Congo. Since then, outbreaks have appeared sporadically in Africa.
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Origin of Ebola virus remains unknown
The natural reservoir host of Ebola virus remains unknown. However, on the basis of evidence and the nature of similar viruses, researchers believe that the virus is animal-borne and that bats are the most likely reservoir. Four of the five virus strains occur in an animal host native to Africa.
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Ebola and Marburg Virus
Ebola and Marburg viruses are highly virulent in humans and non human primates, ends in death.
Both the viruses are identified to cause African hemorrhagic fevers
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Filo virusFilo is Latin for Thread
Marburg and Ebola are members of the Filoviridae
Appear as long threads,
Can be U shaped,
Genome 19 kb long
Enveloped viruses.
A single stranded, unregimented, -Helical, –ve sense RNA genome 80 nm Diameter
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Fruit Bats Harbour Virus and Spread the Virus
Fruit bats are believed to be the normal carrier in nature, able to spread the virus without being affected. Humans become infected by contact with the bats or a living or dead animal that has been infected by bats.
FRUIT BATS SPREAD THE INFECTION
Ebola haemorrhagic fever
Ebola virus disease (EVD), Ebola haemorrhagic fever (EHF) Ebola is a disease of humans and other mammals caused by Ebola virus. Signs and symptoms typically start between two days and three weeks after contracting the virus, with a fever, sore throat, muscle pain and headaches. Then, vomiting, diarrhoea and rash usually follows, along with decreased function of the liver and kidneys. Around this time, infected people may begin to bleed both within the body and externally. Death, if it occurs, is typically six to sixteen days after symptoms appear and is often due to low blood pressure from fluid los
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Ebola haemorrhagic fever Around this time, infected people may begin to bleed both within the body and externally. Death, if it occurs, is typically six to sixteen days after symptoms appear and is often due to low blood pressure from fluid loss
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Events on EbolaEbola virus were discovered in 1976 with occurrence of two severe epidemics of hemorrhagic fever in Sudan and Zaire.
The Epidemic involved > 500 persons and killed > 400 infected individual.
The importance of epidemic lies with in each outbreak hospital staff become infected through close contact with patients, their blood and excreta.
The mean time of death from onset to symptoms is 7 – 8 days.
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2014 Ebola virus epidemic in West Africa
In March 2014, the World Health Organization (WHO) reported a major Ebola outbreak in Guinea, a western African nation Researchers traced the outbreak to a two-year old child who died on 28 December 2013. The disease then rapidly spread to the neighbouring countries of Liberia and Sierra Leone. It is the largest Ebola outbreak ever documented, and the first recorded in the region
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Spread of EBOLA
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Reservoir Hosts
Reservoirs can be a Rodent or Bat
Humans infected accidentally
Monkeys are not proved as reservoirs as die with infection early
Infected humans are rich source of infections to others.
By direct contact with blood and body fluids of infected persons can spread the disease
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Spread of Infections
Transmission appears to be associated with contamination of Blood, Blood stained body fluids or tissues.
Nosocomial spread is common mode of spread, Doctors and Nurses at risk when attending the patients.
Transmission by sexual intercourse has been on record from a case of man infecting his wife 83 days after initial infection.
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Viral Replication
The viruses are grown in variety of cell lines including
Vero
M A 104
S W 13 cells
Filoviruses replicates in the cytoplasam
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Pathology and Pathogenesis
The viruses belong to group of Filo viruses
The viruses have tropism for Cells of macrophage system
Dendritic cells
Interstitial fibroblasts
Endothelial cells
Progress of EBOLA
Mode of Spread
Infected Patient a Concern to Health Workers
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Virus infect Several Organs
High titer of viruses are found in
Liver
Spleen,
Lungs
Kidneys
Blood
Other Body fluids
SymptomsSymptoms usually begin with a sudden influenza-like stage characterized by feeling tired, fever, pain in the muscles and joints, headache, and sore throat. The fever is usually greater than 38.3 °C (100.9 °F).This is often followed by: vomiting, diarrheal and abdominal pain. Shortness of breath and chest pain may occur next along with swelling, headaches and confusion. In about half of cases the skin may develop a maculopapular rash.
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How the Illness is Presented in Marburg and Ebola
Fever
Head ache
Sore throat
Muscle pain
Abdominal pain,
Vomitting
Diarrhea
Incubation period 3 -9 days in Marburg
In Ebola 2 – 21 days.
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Serious manifestation of Ebola and Marburg
Internal and External
bleeding,
Shock,
Death
When you suspect EBOLA
When the diagnosis of EVD is suspected, the travel and work history along with exposure to wildlife are important factors to consider. The diagnosis is confirmed by isolating the virus, detecting its RNA or proteins, or detecting antibodies against the virus in a person's blood. Isolating the virus by cell culture, detecting the viral RNA by polymerase chain reaction (PCR) and detecting proteins by enzyme-linked immunosorbent assay (ELISA) works best early and in those who have died from the disease. Detecting antibodies against the virus works best late in the disease and in those who recover
Laboratory testingChanges on laboratory tests as a result of Ebola virus disease include a low platelet count in the blood, an initially decreased white blood cell count followed by an increase in the white blood cell count, elevated levels of the liver enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and abnormalities in clotting often consistent with disseminated intravascular coagulation (DIC) such as a prolonged prothrombin time, partial thromboplastin time, and bleeding time
Diagnosis can be difficult to distinguish EVD from other infectious diseases such as malaria, typhoid fever and meningitis. Confirmation that
symptoms are caused by Ebola virus infection are made using the following investigations:
antibody-capture enzyme-linked immunosorbent assay (ELISA)
antigen-capture detection tests
serum neutralization test
reverse transcriptase polymerase chain reaction (RT-PCR) assay
electron microscopy
virus isolation by cell culture.
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Diagnosis
Viruses are isolated from Blood by cell culture on Vero cells ( Vero –E 6 )
ELISA for antigen detection
ELISA for IgM
RT - PCR
Infection controlThe risk of transmission is increased amongst Ebola caregivers. Recommended measures when caring for people infected with Ebola include barrier-isolation, sterilizing equipment and surfaces, and wearing protective clothing including masks, gloves, gowns, and goggles If a person with Ebola dies, direct contact with the body of the deceased patient should be avoided
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Control of InfectionIsolation facilities within the Hospital remain the most important effective measure.
Barrier nursing remain the basic need in control of infection spread
WHO RECOMENDS One step recommended by the World Health Organization is the education of the general public of the risk factors for Ebola infection and of the protective measures individuals can take. These include avoiding direct contact with infected people and regular hand washing using soap and water. Bush meat, an important source of protein in the diet of some Africans, should be handled with appropriate protective clothing and thoroughly cooked before consumption.
Trends on QUARANTINE
Quarantine, also known as enforced isolation, is usually effective in decreasing spread. Governments often quarantine areas where the disease is occurring or individuals who may transmit the disease outside of an initial area. In the United States, the law allows quarantine of those infected with Ebola viruses. During the 2014 outbreak, Liberia closed schools. On October 16, 2014, some schools were closed in Ohio and Texas as a precaution after one of two nurses who contracted Ebola after caring for Dallas Ebola victim Thomas Eric Duncan, had returned to the Cleveland area and may have been on the same plane as some students, teachers and parents of students from those schools.
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The health care workers should
Avoid
Infected Blood,
secretions,
Tissues,
Wastes
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Treatment of Ebola and Marburg
Antiviral drugs are not available
Interferon's are not effective
To date no Vaccine
Electrolyte corrections
Dealing with hemorrhagic complications.
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WHO Declares as International Public Health emergency
On 8 August 2014, the WHO declared the epidemic to be an international public health emergency. Urging the world to offer aid to the affected regions, the Director-General said, "Countries affected to date simply do not have the capacity to manage an outbreak of this size and complexity on their own. I urge the international community to provide this support on the most urgent basis possible. By mid-August 2014, Doctors Without Borders reported the situation in Liberia's capital Monrovia as "catastrophic" and "deteriorating daily".
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Ebola and Bioterrorism Ebola virus is classified as a biosafety level
4 agent, as well as a Category A bioterrorism agent by the Centres for Disease Control and Prevention. It has the potential to be weaponized for use in biological warfare, and was investigated by the Biopreparat for such use, but might be difficult to prepare as a weapon of mass destruction because the virus becomes ineffective quickly in open air.
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SIMPLE MEASURES CAN SAVE US
HAND WASHING THE MOST IMPORTANT
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NEVER FORGET TO WEAR THE GLOVES AT EVERY STAGE WHEN WE COME IN CONTACT
WITH PATIETNS AND SCECRETIONS
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BE SCIENTIFIC IN APPROACH TO YOUR SUSPECTED
PATIENTS
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Learn and Practice the Biosafety as No infection is
Trivial to life
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FOLLOW BIOSAFETY AT EVERY STAGE OF WORK
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NEVER FORGET TO QURANTINE THE SUSPECTED
PATIETNS
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Barrier Nursing remains the only best option in
Prevention
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References and Resources
CDC on Ebola
WHO The current concepts on EBOLA
Google Images
Wikipedia resources on EBOLA
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Ebola is Greater Biohazard than we
Imagine
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OUR VISION TO FUTURE
In spite many advances in Science, Medicine and Technology we deal with Infection and Biohazard in casual ways, not following many simple procedures like Hand Washing. The AIDS, SARS, INFLUENZA AND EBOLA Teaches many Lessons
everyone's life is at threat from patients and casual approaches will make the Doctors, nurses, or families and the
Society at Risk I wish all the Microbiologists, and Public Health Professionals to take more active interest to Improve the Awareness on Infection Control, Let us not forget every
fear and danger has some solutions, try practising the BIOSAFTEY
Dr.T.V.Rao MD Professor of Microbiology