EbolaThe Deadly

African Virus

Davood YadegariniaProfessor 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

Scientific ClassificationOrder: 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

Sudan(SUDV)

Group : Group V (-)sense RNA

Order : MononegaviralesFamily : Filoviridae

Genus : Ebolavirus

Bundibugyo(BDBV)

Tai forest(TAFV)

Formerly Cote d-Ivoire

Species

Zaire ebola(EBOV)

The most dangerous

Reston(RESTV)

Non-humans

Ebola Taxonomy

Ebola hemorrhagic feverFatality 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

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.

MASS GRAVES FOR EBOLA VICTIMS

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

– exist throughout the world

– endemic to Africa

– filamentous ssRNA- (antisense) viruses

Image courtesy of the Centers for Disease Control

Natural Reservoir

Suspected to be a zoonotic (animal-borne)

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 YEAR REGIONS AFFECTED

DISCRIPTION

FIRST 1976 Democratic republic of congo (ZAIRE) &

sudan

First outbreak of Ebola. Hemorrhagic fever

SECOND 1989 Reston ,Virginia

mysterious outbreak.  (initially diagnosed as Simian hemorrhagic fever virus (SHFV)) among a shipment of crab-eating macaque monkeys imported from the Philippines.  named Reston ebolavirus (REBOV)

THIRD 2014 WEST AFRICA -affecting Guinea,

Sierra Leone, Liberia and Nigeria.

largest outbreak to the date

Case counts as of October 20, 2014

Total Case Count Laboratory Confirmed Cases

Total Deaths

9216

4218**

4555**

**Numbers are lower than actual laboratory confirmed cases and deaths because stratified data are temporarily unavailable for Liberia.

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

Case counts as of October 20, 2014

*Numbers remain unchanged or are lower than actual cases because stratified data are temporarily unavailable for Liberia.

Countries with Widespread Transmission

Countries with Travel-associated Cases

Case by country Total case count Laboratory confirmed cases

Total death

Senegal 1 1 0

Spain 1 1 0

Case by country Total case count Laboratory confirmed cases

Total death

Nigeria 20 19 8

United states 3 3 1

Countries with Localized Transmission

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)

• 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.

how do people become infected with the virus?

• 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.

Transmission(cont)

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You can’t get E bola through air

Facts about

EbolaYou can’t get E bola

through waterYou 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.

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.

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

EFFECT OF EBOLA

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 feverTarget 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 (pro-inflammatory cytokines, pro-coagulants, and anticoagulants)

These injure blood vessels even worse, resulting in permanent bleeding.

Eventually, the entire body is leaking and dissolving

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

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

Signs and Symptoms

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

Later in disease course or after recovery

IgM and IgG antibodies

Retrospectively in deceased patients Immunohistochemistry testing

PCR

Virus isolation

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 feverPrevention

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 PrecautionsRoutine Hand washingHandle and Dispose of Shar Instruments SafelyCook meat thoroughlyEnvironment 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