Transcript Ebola

Ebola
The Deadly
African Virus
Davood Yadegarinia
Professor of Infectious Diseases and Tropical Medicine
Research Center, Shahid Beheshti University of Medical Sciences
Definition
Ebola virus disease (formerly known as Ebola
hemorrhagic fever) is:
 A disease caused by the Ebola virus
 Is severe- fatality rate 90%
 Affects human and non human primates
Ebola Taxonomy
Scientific Classification
Order: Mononegavirales
Family: Filoviridae
Genus: Ebola like viruses
Species: Ebola
Subtypes
-5 types
– Ebola-Zaire, Ebola-Sudan,Ebola-Ivory Coast
• disease in humans
– Ebola-Reston
• disease in nonhuman primates
Ebola Taxonomy
Group
Order
Family
Genus
: Group V (-)sense RNA
: Mononegavirales
: Filoviridae
: Ebolavirus
Species
Bundibugyo
(BDBV)
Sudan
(SUDV)
Tai forest
(TAFV)
Formerly
Cote dIvoire
Zaire ebola
(EBOV)
The most
dangerous
Reston
(RESTV)
Non-humans
Ebola hemorrhagic fever
Fatality Rates:
• Ebola-Sudan – 60%
• Ebola-Zaire – 77-88%
• Ebola-Reston – Found in
monkeys, has not shown to be
fatal in humans
• Ebola-Cote D’Ivoire – Only one
human case recorded, patient
survived
MASS GRAVES FOR
EBOLA VICTIMS
Not much is known about the
body’s response because of
the dangers of handling
samples from infected patients
and the short time span
available for investigation.
Filoviridae or “Filoviruses”
• Most mysterious virus group
• Pathogenesis poorly understood
• Ebola
– natural history/reservoirs unknown ,
researchers believe the most likely natural
hosts are fruit bats
Image courtesy of the Centers for Disease Control
– exist throughout the world
– endemic to Africa
– filamentous ssRNA- (antisense) viruses
Natural Reservoir
Suspected to be a zoonotic (animalborne)
However, it is unknown what
organism carries it naturally
without being infected
Suspected vectors
• Bats
• Primates (in some cases, have
been confirmed)
• Basically any other animal native
to Africa, including mosquitoes,
ticks, birds, reptiles
History of Ebola virus
• Ebola first appeared in 1976 in two simultaneous
outbreaks.
- Near the Ebola River in the Democratic
Republic of Congo
- A remote area of Sudan.
STROKES
FIRST
YEAR
1976
REGIONS
AFFECTED
Democratic republic
of congo (ZAIRE) &
sudan
SECOND
1989
Reston ,Virginia
THIRD
2014
WEST AFRICA
-affecting Guinea,
Sierra Leone, Liberia
and Nigeria.
DISCRIPTION
First outbreak of
Ebola. Hemorrhagic
fever
mysterious
outbreak. (initially
diagnosed as Simian
hemorrhagic fever
virus (SHFV)) among
a shipment of crabeating macaque
monkeys imported
from the
Philippines. named
Reston ebolavirus
(REBOV)
largest outbreak to the
date
Case counts as of October 20, 2014
Total Case Count
9216
Laboratory
Confirmed Cases
Total Deaths
4218**
4555**
**Numbers are lower than actual laboratory confirmed cases
and deaths because stratified data are temporarily unavailable
for Liberia.
Case counts as of October 20, 2014
Countries with Widespread Transmission
Cases by Country
Total Case Count
Laboratory
Confirmed Cases
Total Deaths
Guinea
1519
1217
862
Liberia
4249

2484
Sierra Leone
3410
2977
1200
Total Case Count
9178
4194*
4546
*Numbers remain unchanged or are lower than actual cases because
stratified data are temporarily unavailable for Liberia.
Countries with Travel-associated Cases
Case by country
Total case count
Laboratory
confirmed cases
Total death
Senegal
1
1
0
Spain
1
1
0
Countries with Localized Transmission
Case by country
Nigeria
United states
Total case count
Laboratory
confirmed cases
Total death
20
19
8
3
3
1
Transmission
Environment to Human :
Fruit bats-natural reservoir
Gorilla, chimpanzee, monkey, porcupine, duiker
Human to human :
1. Direct contact
2. Contaminated medical equipment
3. Traditional burial rituals
4. Medical workers
5. Survivors(via semen for 2 months)
how do people become infected
with the virus?
• Ebola is introduced into the human population through
close contact with the blood, secretions, organs or other
bodily fluids of infected animals.
•
In Africa, infection has occurred through the handling
of infected chimpanzees, gorillas, fruit bats, monkeys,
forest antelope and porcupines found ill or dead or in
the rainforest.
Transmission(cont)
• Ebola is extremely infectious but not extremely contagious. It
is infectious, because a very small amount can cause illness.
Laboratory experiments on nonhuman primates suggest that
even a single virus may be enough to trigger a fatal infection.
• Instead, Ebola could be considered moderately contagious,
because the virus is not transmitted through the air. The most
contagious diseases, such as measles or influenza, virus
particles are airborne.
You can’t get E bola through air
Facts about
Ebola
You can’t get E bola
through water
You can’t get Ebola
through food
You can only get Ebola from:
Touching
the blood or body fluids of a person who is sick with or has died from Ebola.
Touching contaminated objects, like needles.
Touching infected animals, their blood or other body luids, or their meat.
Ebola poses no signiicant risk to the United States.
CS250586A
Who is most at risk?
During an outbreak, those at higher risk of infection are:
 health workers;
 family members or others in close contact with infected
people;
 mourners who have direct contact with the bodies of the
deceased as part of burial ceremonies; and
 hunters in the rain forest who come into contact with dead
animals found lying in the forest.
More research is needed to understand if some groups, such
as immuno-compromisaed people are more susceptible than
others to contracting the virus.
EFFECT OF EBOLA
 the patients will have Diarrhea.
 Pharyngitis with the inflammation of the throat and eye.
 causes severe damage to the skin.
 attacks every tissue and organ of the body except the skeletal muscles
and bones.
 can attack the connective tissues that are rapidly multiplying in collagen.
 causes small blood clots to form in the bloodstream of the patient and
forms red spot on the skin
 Spontaneous bleeding then occurs from body orifices and gaps in the skin
EHF & EVD
EHF ( Ebola
Hemorrhagic Fever ) :
Internal and External Bleeding occurs
Genital swelling
Increased feeling of pain in the skin
Rash over the entire body that often contains blood
Roof of mouth looks red
EVD ( Ebola Virus Disease) :
Bleeding dose not occur
Ebola hemorrhagic fever
Target Organs and Damage Methods
 Target mainly small capillary vessels. Attach to walls,
cause leakage of blood and serum into surrounding
tissue.
 When white blood cells attack the virus, they dissolve –
this releases a chemical into the blood stream that
signals the release of other chemicals (proinflammatory cytokines, pro-coagulants, and
anticoagulants)
 These injure blood vessels even worse, resulting in
permanent bleeding.
Signs and Symptoms
Early symptoms :
 Influenza(fatigue,fever,headache,joint & abdominal pain)
 Vomiting,diarrhea
 Loss of appetite
 Sore throat,chest pain,hiccups,shortness of breath, trouble
swallowing
 Weakness
 Maculopular rash(50% cases)
 Myalgia(muscular pain or tenderness),back pain
 Mucosal redness of the oral cavity
Signs and Symptoms
Acute symptoms :
 Bleeding from puncture sites and mucous
membrane(eg.nose,gums and gastrointestinal tract)
 Internal and subcutaneous bleeding
 anuria(absence of urine formation)
 raddening of eyes,bloody vomit
 Impaired blood clotting
 Multiple organ dysfunction
syndrome which leads to death
Diagnosis
• Diagnosing Ebola in an person who has been infected for
only a few days is difficult, because the early symptoms,
such as fever, are nonspecific to Ebola infection and are
seen often in patients with more commonly occurring
diseases, such as malaria and typhoid fever.
• However, if a person has the early symptoms of Ebola and
has had contact with the blood or body fluids of a person
sick with Ebola, contact with objects that have been
contaminated with the blood or body fluids of a person sick
with Ebola, or contact with infected animals, they should be
isolated and public health professionals notified. Samples
from the patient can then be collected and tested to confirm
infection.
Laboratory tests used in diagnosis
include:
Timeline of Infection
Diagnostic tests available
Within a few days after symptoms
begin

Antigen-capture ELISA testing

IgM ELISA

PCR

Virus isolation

IgM and IgG antibodies

Immunohistochemistry testing

PCR

Virus isolation
Later in disease course or after
recovery
Retrospectively in deceased patients
Treatment
 No specific vaccine or medicine (e.g., antiviral drug) has
been proven to be effective against Ebola.
 Symptoms of Ebola are treated as they appear.
 The following basic interventions, when used early, can
significantly improve the chances of survival:
1-Providing intravenous fluids (IV)and balancing
electrolytes (body salts)
2-Maintaining oxygen status and blood pressure
3-Treating other infections if they occur
Treatment
 Some experimental treatments developed for Ebola have
been tested and proven effective in animals but have not
yet been tested in randomized trials in humans.
 Recovery from Ebola depends on the patient’s immune
response. People who recover from Ebola infection
develop antibodies that last for at least 10 years, possibly
longer.
Prevention
 There is no FDA-approved vaccine available for
Ebola.
 If you travel to or are in an area affected by an Ebola
outbreak, make sure to do the following:
1-Practice careful hygiene. Avoid contact with blood and body
fluids.
2-Do not handle items that may have come in contact with an
infected person’s blood or body fluids.
3-Avoid funeral or burial rituals that require handling the
body of someone who has died from Ebola.
Prevention
4-Avoid contact with bats and nonhuman primates or
blood, fluids, and raw meat prepared from these
animals.
5-Avoid hospitals where Ebola patients are being
treated. The U.S. embassy or consulate is often able
to provide advice on facilities.
6-After you return, monitor your health for 21 days
and seek medical care immediately if you develop
symptoms of Ebola
Ebola hemorrhagic fever
Prevention
Classified as Biosafety level 4
(greatest threat to humans)
Extensive precautions taken when
dealing with suspected cases to
limit transmission
• Several layers of protective
clothing covering entire body
(up to four)
• Complete equipment
sterilization
• Quarantine of Ebola HF
patients
Prevention
 Healthcare workers who may be exposed to people with Ebola
should follow these steps:
1-Wear protective clothing, including masks, gloves, gowns,
and eye protection.
2-Practice proper infection control and sterilization measures.
3-Isolate patients with Ebola from other patients.
4-Avoid direct contact with the bodies of people who have
died from Ebola.
Prevention
• Notify health officials if you have had direct
contact with the blood or body fluids, such as
but not limited to, feces, saliva, urine, vomit,
and semen of a person who is sick with Ebola.
The virus can enter the body through broken
skin or unprotected mucous membranes in, for
example, the eyes, nose, or mouth
PRECAUTIONS
Use Standard Precautions
Routine Hand washing
Handle and Dispose of Shar Instruments Safely
Cook meat thoroughly
Environment Cleaning
FIVE TYPES OF HAND HYGEINE
ISOLATION PROCEDURES
Select Site for the Isolation Area
Isolation area must consist of :
1)An isolated toilet 2)Adequate ventilation 3)Screened
windows
Plan How to Arrange the Isolation Area
Thanks for your patience