Ebola

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What is Ebola?

Ebola virus got its name from the Ebola river, a small river in the Congo

Occurs naturally across sub-Saharan Africa

One strain lives in the Philippines

Outbreaks in humans have been known for many years; not new

Ebola virus

Considered by WHO as a risk group 4 pathogen (requires biosafety level 4) containment

Considered by CDC to be a category A (bioterrorism) agent

Rapid mutation rate (as fast as influenza)

Where is the current outbreak happening?

Currently spreading in 3 West African countries

Guinea, Sierra Leone, and Liberia

A few imported cases in Nigeria, but under control

Index case was a 2-year-old child in Guinea in December 2013

Ebola virus

A virus in the Filoviruses group

Two families; Marburg and Ebola

The current Ebola strain (Zaire) is one of 5, the worst

Cause hemorrhagic fever diseases in mammals

Now known as Ebola virus disease (EVD)

Ebola virus structure

A filamentous single-stranded RNA negative-sense virus

Requires transcription to positive RNA before it can translate and replicate

Enveloped

One major glycoprotein

Seven structural proteins

What is Ebola?

Natural reservoir is the West African fruit bat, causes no known disease in bats

Can infect humans and primates, where it is often fatal

Bats and other animals are eaten in Africa; “bush meat”

Bat range is changing due to deforestation

Ebola disease

Virus is transmitted in the blood and body fluids of the source

Enters the body through non-intact skin or mucous membranes

Glycoprotein attaches to 2 targets

A cholesterol transport protein (NPC1)

TIM-1 protein

Endocytosed, vesicle opens, replicates in cytoplasm, and kills the cell

Ebola disease

Replicates in and destroys three types of human cells/tissues

Endothelium

Causes hemorrhage

Macrophages/dendritic cells

Spreads rapidly to lymph nodes and spleen

Liver, spleen, adrenals and lymph nodes

Liver necrosis causes coagulopathy (prevents clotting)

Causes multi-organ system failure and death

Ebola signs and symptoms

Initial signs and symptoms begin 8-10 days after exposure

“Influenza-like;” fever, headache, joint pain, abdominal pain

Release of cytokines from endothelium

Progress to vomiting, diarrhea, hiccups, maculopapular rash

Late disease may include hemorrhage

Mucosa (conjunctiva), skin (petechiae, hematomas), GI tract (vomit, stool)

Disseminated intravascular coagulation

CDC case definition

Person Under Investigation (PUI)

A person who has both consistent signs or symptoms and risk factors as follows:

Elevated body temperature (100.4 F) or subjective fever or symptoms, including severe headache, fatigue, muscle pain, vomiting, diarrhea, abdominal pain, or unexplained hemorrhage; AND

An epidemiologic risk factor within the 21 days before the onset of symptoms

http://www.cdc.gov/vhf/ebola/exposure/risk-factors-when-evaluating-person-for-exposure.html

CDC case definition

Confirmed case

Laboratory-confirmed diagnostic evidence of Ebola virus infection

A PCR test on blood is done at MDCH (Lansing), confirmed by the CDC in Atlanta

Definitive test must be done at least 72 hours after fever (before 72 hours, the viral load in the blood may be too low to detect)

Ebola treatment

There are no FDA-approved treatments for Ebola, but there are investigational approaches that are promising

At least 5 types of antiviral drugs

A monoclonal antibody (ZMapp)

Immune serum from survivors

Several vaccines

The most effective treatment is supportive care

Most deaths occur due to dehydration, electrolyte imbalance, and loss of hemostasis

Ebola personal protective equipment

All surfaces of the body are covered by at least one layer

Hood, face shield, gown, apron, boots, 2 gloves

Includes a respirator for respiratory protection

Patient care requires 2 people at all times

Minimize people entering the room

Ebola surveillance

The CDC monitors all international traffic from the endemic areas of Africa

CDC contacts MDCH and the local county health department

The health department should know if we have a person from West Africa in the area

The health department monitors the person twice per day (once in person)

If the person becomes sick, directs the person where to go and tells the hospital they are coming

Ebola hospital workflow

The patient presents to the Emergency Department, is placed in the decontamination room while their suite is prepared

The Ebola team is called in and prepares the suite for the patient, gets the patient from the ED, and takes them to their room

The patient is cared for in isolation until their test is negative, they are transferred, or they die

Why is the current outbreak happening in West Africa?

Poverty and lack of health care systems

Funeral and burial traditions

Spread from rural to urban areas

Spread within hospitals by and to workers

Distrust of government and healthcare systems (sick people hide)

Hospitals became overwhelmed and shut down

Misdiagnosed as cholera for almost 4 months; weak disease surveillance systems

Low literacy rate of the population

International attention was slow and inadequate

Is Ebola a threat to Kalamazoo?

It is unlikely that a person with Ebola would present to a Kalamazoo facility

It is very likely that people who meet the screening criteria for Ebola will present to a Bronson facility

Fever and a history of travel from or connection to West Africa

We must be prepared to care for a patient with for Ebola in the same way we are prepared to care for patients with other infectious diseases like meningitis or influenza

The future of Ebola; CDC

If conditions remain unchanged, the situation will become much worse.

We know how to control and eventually stop the epidemic. Halting the epidemic requires placing up to 70% of patients into either an Ebola Treatment Unit or in a community setting in which the risk of disease transmission is reduced and safe burials are provided.

The cost of delay will be devastating. The number of cases is doubling about every 20 days. Every month of delay in reaching the 70% target will increase the number of patients, which means more cases and more deaths and the need for even more beds and other resources.

Ebola prevention and control

Prevention and control of Ebola infection are theoretically easy

The virus is not transmissible until the patient develops fever

Early detection of potential cases through screening

Isolation of the patient and use of special precautions; standard, contact and droplet

Contact tracing

Quarantine of contacts for 21 days

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