Ebola 3B Transmission, Biology, Pathophysiology

white blood cells

After entering the bloodstream (e.g., via an abrasion or mucous membrane), the Ebola virus invades ______________________________

replication

After entering the cell, the Ebola virus begins the process of ___________________________.

infection and death or recovery.

All this happens over a remarkably short timespan; ten to nineteen days elapse between _______________________ ​

joint pain, hearing loss, chronic hepatitis (inflammation of the liver), and vision problems

As mentioned earlier, survivors of Ebola may experience long-term health problems, including __________________________________________________________________.

first appears among human populations

Because the reservoir for the Ebola virus has not yet been identified, determining the way that the virus __________________________ during an outbreak is difficult.

better able to travel unnoticed to another cell

By enveloping itself with the cell membrane, the virus is _______________________________________. In this way, the cycle continues, and the virus proliferates through the body. ​

women

Despite the known risks, _____________ continue to care for their loved ones with Ebola. This increases the ability of Ebola to spread throughout families and into the wider community.

nucleoprotein, a capsid, and an envelope

Each viral particle, or virion, contains a single strand of genetic material, which is surrounded by ______________________________

an extreme inflammatory response

Ebola can cause disease by triggering ____________________________ in the host, which can severely weaken the host's immune system.

objects that have been contaminated with these fluids

Ebola is spread from person to person through direct contact with bodily fluids of an infected person or _____________________________________.

release infectious bodily fluids

Ebola often causes the individual to abruptly _____________________________________ by vomiting, diarrhea, and, in some cases, external bleeding.

filovirus

Ebola virus is a ______________________, meaning that it resembles a curled piece of thread, or filament.

pathogenicity

Ebola's glycoprotein also contributes to the high _________________________________(i.e., its disease-causing capability) of the virus.

Ebolavirus glycoprotein

Embedded within the viral envelope is the ____________________________, which facilitates the virus's binding and invasion into a host cell.

crossing its protective membrane

First, though, the virus must invade the cell by _____________________________________.

large masses of people

Funerals attract ________________________________, many of whom come in proximity and contact with the dead.

a corpse

Given that Ebola virus remains present in high levels even after death, _________________can continue to spread the disease if it is not handled properly.

months or even years afterward

Given the devastating impact that Ebola can have on nearly every part of the body, it is perhaps unsurprising that the effects of infection can persist for _____________________________________________.

many subsequent funerals.

Given the potential for the deceased's grieving relatives and friends to be exposed to the virus during these burial practices, one funeral can lead to ______________________________

Days 14-21:

If the disease progresses, the individual may experience heavy bleeding (internally or externally), confusion, coma, shock, and eventually death.

care for immediate and extended family members

In Sierra Leone, Liberia, and Guinea, women typically are expected to __________________________ who become ill.

to each other and to the extracellular matrix

In addition to helping the virus bind to the host cell membrane, the glycoprotein can make it difficult for infected cells to stick ____________________________________

relapse (i.e., experience a disease recurrence)

In rare cases, a survivor may ______________________________ from the virus spreading from these sites into other areas in the body.

critical amounts of bodily fluids

In severe cases of the disease, the infection leads to organ failure and the loss of _____________________________.

• Flu-like symptoms, including fatigue and soreness • Severe fever, diarrhea, and vomiting • Bleeding from the eyes, ears, mouth, nose, and other mucous membranes • Rash on the torso and upper extremities • Headache, confusion, and seizures

In summary, the virus wreaks havoc on the tissues and organs of infected people, causing them to develop the following signature symptoms of an Ebola infection:

strong family ties and community relations

In the 2014 Ebola outbreak, transmission was linked to certain aspects of West African culture, including the tendency to have __________________________.

the Guinean toddler index case

In the case of the 2014-16 Ebola outbreak, _________________________ was thought to have been infected by fruit bats dwelling in the towering reeds and oil palm cultivations that surrounded his isolated village.

speedy rental cars for the virus

In this way, white blood cells can act as __________________________________, allowing it to infect a variety of cells throughout the body.

hijack the machinery

Like all viruses, Ebola must _____________________________ of host cells in order to replicate.

solid tissues to break down

Loss of cell adhesion causes ___________________________________.

Liberia and Sierra Leone

Loss of healthcare workers was especially difficult for ___________________________ as years of conflict and political instability had left both countries with weak healthcare systems and limited workforces.

many critical tissues and organs

Moreover, because the Ebola virus can invade almost any type of human cell (not just immune cells), the virus can damage ____________________________________ throughout the body.

in the air or via insect bites

No evidence indicates that Ebola can be spread _____________________________.

assemble

Once all of the components of a virus are created, the pieces ______________________ at the surface of the host cell.

clot

Once the virus spreads to the spleen and kidneys, it destroys the cells that help the blood to ____________, further increasing the risk of hemorrhage.

800

Over ________ cases of Ebola were reported among healthcare workers since January 2014, and two-thirds (66%) of those infected died.

4 to 10 days

People become infectious only after they develop symptoms of the disease, typically ________________ after exposure.

chimpanzees, fruit bats, and monkeys

Previous outbreaks have been linked to contact with several species, including _______________________

its reservoir

Scientists suggest that the Ebola virus was hiding out in ________________ during this fifteen-year hiatus (1979 to 1994)

the largest outbreaks in Africa

The Sudan, Bundibugyo, and Zaire viruses have caused _______________________________,

21 to 32 times more likely

The WHO reports that healthcare workers are ________________________ to be infected with Ebola than people in the general adult population.

nucleoprotein

The _______________________ functions similarly to a nucleus, holding the genetic material within the cell.

the liver, spleen, and lymph nodes

The first stops for the invaded immune cells are _______________________________________.

Day 7:

The individual begins exhibiting the first symptoms of the disease, such as flu-like symptoms, severe malaise, and fatigue. These symptoms mimic those of malaria, typhoid fever, and bacterial respiratory infection, which are relatively common in West Africa. This helps to explain why the first cases of Ebola in 2014 failed to raise more red flags among healthcare providers.

Day 1:

The individual is exposed to the disease, meaning that the virus enters the body.

Days 11-14:

The individual may present with more serious symptoms, including severe vomiting, diarrhea, and low blood pressure.

the kidney, brain, and adrenal gland

The infected immune cells then travel to other tissues and organs, such as __________________________. ​

macropinocytosis

The virion is swiftly engulfed by the cell membrane through a process called ____________________________ (which can be pictured as the cell's way of taking a large gulp).

interferon

The virus fights the host's defenses by blocking the release of _________________, a protein made by immune cells to prevent viral replication.

8

The virus' genetic material instructions that code for _______ proteins necessary for reproduction and protection against the host's immune system.

reproduction and protection

The virus' genetic material instructions that code for eight proteins necessary for ________________________________________ against the host's immune system.

the bloodstream and lymphatic system

The white blood cells travel around the body via _____________________________________________.

the inside of the eye and the central nervous system (brain and spinal cord)

These "immunologically privileged sites" include ______________________________________________.

fight infection

These organs, the liver, spleen, and lymph nodes, help the body ____________________. However, this does not stop Ebola from spreading.

its new viral envelope

They protrude (or "bud") from the cell, using the cell's membrane as ___________________________________.

surface glycoprotein

This invasion is facilitated by its __________________________, which is present on the surface of the virus and which binds to receptors on the host cell membrane.

receptors on the host cell membrane

This invasion is facilitated by its surface glycoprotein, which is present on the surface of the virus and which binds to ____________________________________.

stop the outbreak

This shortage hindered the nations' ability to _________________ as medical professionals began to die of the disease.

multiple organ failure or shock

Those who succumb to the disease die from _______________________________________ caused by severe infection and internal bleeding.

removing harmful toxins in the bloodstream

Upon reaching the liver, the virus can kill the cells responsible for ____________________________________________

a template

Using the single strand of genetic material contained within an Ebola virion as __________________, a viral protein called the large or L protein generates a complementary strand.

the large or L protein

Using the single strand of genetic material contained within an Ebola virion as a template, a viral protein called __________________________ generates a complementary strand.

internal bleeding

When the virus attacks blood vessel cells, the vessels may become leaky, which can cause ______________________ and the loss of large amounts of blood, known as hemorrhaging.

linger for extended periods of time

While the virus generally clears from the survivor's body following recovery, in some circumstances the virus can __________________________________________.

new viral proteins

With the help of the host cell, this new strand then is used to synthesize ________________________, as well as more copies of the original template strand.

more copies of the original template strand

With the help of the host cell, this new strand then is used to synthesize new viral proteins, as well as __________________________________.

Liberia

________________ had only one doctor for every 100,000 people,

Sierra Leone

__________________ had only two doctors for every 100,000 people,

direct contact

___________________ means that in order to become infected with the Ebola virus, the fluid must enter the person's body through contact with damaged tissue (e.g., a cut) or a mucous membrane or by entering the bloodstream (e.g., a needle stick)

the Zaire virus

________________________ was responsible for the 2014-16 West Africa outbreak.

Traditional preparations for burial

__________________________ involve washing, touching, and kissing the deceased individuals.

hiatus

a pause or gap in a sequence, series, or process

bodily fluids

blood, semen, urine, stool, or saliva

butchering, cooking, or eating the infected animal

contact with the Ebola virus animal host can occur during ______________________________.

fruit bats of the Pteropodidae family

evidence suggests that _________________________________ are natural Ebola virus hosts.

steroid hormones and regulate blood pressure

if the virus reaches the adrenal glands, it destroys the cells that help produce _______________________________.

healthcare workers, family members of infected people, and mourners involved in burial rituals

individuals who are at highest risk of Ebola infection during an outbreak include ________________________________________________. ​

1979 to 1994

no cases of Ebola were identified during the interval from ________________________.

disease-causing capability

pathogenicity

the pathogen's long-term host

reservoir

the bodily fluids of an animal vector

the Ebola virus is transmitted to humans through contact with ________________________.

extracellular matrix

the collection of molecules that provides structure and support for surrounding cells

index case

the first patient found in an epidemiological investigation

four to ten days

the incubation period, which typically lasts from__________________________ .

hemorrhaging

the loss of large amounts of blood, known as

not yet been identified

the reservoir for the Ebola virus has

immune cells

white blood cells

appropriate protective equipment

without proper use of ________________________ and other control measures, healthcare workers who care for Ebola patients are at high risk of contracting the disease.

a complementary strand

​ Using the single strand of genetic material contained within an Ebola virion as a template, a viral protein called the large or L protein generates ________________________________.

"hide out"

​Essentially, the virus can________________ in places that are harder for the immune system to reach.

Zaire, Bundibugyo, Sudan, Reston, and Taï Forest

​Five species of the Ebola virus have been identified: