Watch what the Ebola virus does inside the body in order to spread and survive

Ebola infects and disables immune cells, triggering a cascade of events that leads to small blood clots throughout the body, weakening blood vessels and interrupting blood flow to key organs.

See how the Ebola virus affects blood circulation in the human body

Ebola infects and disables immune cells, causing a cascade of events that result in small blood clots throughout the body, weakening blood vessels, and interrupting blood flow to key organs.

Ebola has an average fatality rate above 50%

The Ebola virus is one of the planet’s most feared bugs. Symptoms begin with fever and fatigue but quickly develop into severe vomiting, diarrhea, and internal and external bleeding. But why is it so deadly? In short, Ebola hijacks the immune system to rapidly make replicas of itself.

There have been close to 40 Ebola outbreaks since 1976

Ebola is a rare but deadly virus that causes severe illness, organ damage, and sometimes internal bleeding. It spreads through contact with infected bodily fluids and is most common in parts of sub-Saharan Africa. This explainer covers its symptoms, transmission, and treatment options.

See how Ebola tore through Guinea, Sierra Leone, and Liberia in 2014-2016.

Learn how monoclonal antibodies, which mimic the body's antibodies, can fight diseases like Ebola.

Learn how monoclonal antibodies, which mimic the body's antibodies, can fight diseases like Ebola

Monoclonal Antibodies mimic the antibodies produced naturally by the immune system. These molecules target specific parts of the virus, preventing them from entering cells or interfering with their ability to cause harm or infection.

See how Ebola tore through Guinea, Sierra Leone, and Liberia in 2014-2016

Frontline traced how the outbreak started and spread across West Africa. documenting first-hand accounts and patient experiences. This Ebola outbreak was the deadliest to date, resulting in over 11,000 deaths.

Three Ebola species are responsible for most large outbreaks of the disease, yet the only approved Ebola vaccine is known to work against just one of them.

Watch how viruses like Ebola can spill over from animals to humans—and vice-versa.

Watch the cumbersome, but necessary, precautions healthcare workers must take to care for and protect themselves while caring for Ebola patients

Treating someone with Ebola involves a painstaking process of suiting up (donning) and peeling off (doffing) protective gear. Doctors follow detailed CDC guidelines. Properly suiting up is key to protecting against fluids that transmit Ebola, and correctly removing a suit that could be contaminated with the virus is also critical.

Watch the cumbersome, but necessary, precautions healthcare workers must take to care for and protect themselves while caring for Ebola patients.

Ebola is a filovirus, meaning it resembles a thread under a microscope, though it sometimes twists and can resemble a bowl of spaghetti.

Ebola's natural reservoir species are likely bats

But the virus doesn't seem to sicken the animals, so capturing an infected bat and performing necessary tests has remained challenging. Though many scientists believe fruit bats are the reservoir species for the virus, Ebola viral RNA fragments were detected in a greater long-fingered bat captured in 2016 in Liberia. The species isn't a fruit bat—it roosts in caves and feeds on insects. The scientist behind the discovery states that he believes the virus likely infects multiple host species and that the hosts may differ regionally. (Some users may encounter a paywall.)

How the most famous Ebola outbreak book got aspects of the disease so wrong

Richard Preston's 1994 book The Hot Zone brought knowledge of Ebola to the masses. But, beyond the poor portrayals of the science and the scientists, the book fostered fearmongering about Ebola, with portrayals of "liquefying," "dissolving," and "bleeding out." These falsehoods about Ebola have persisted for decades and appear to be reinvigorated with every new emergence of the disease.

Scientists have struggled to pin down Ebola's natural reservoir species for decades, but the available evidence suggests that it's very likely fruit and insect-eating bats found in Africa.

See the evolution of Ebola vaccine and treatment development.

Ebola is a filovirus, meaning it resembles a thread under a microscope

Filovirus is derived from the Latin word 'filum', meaning 'thread.' That term describes its thin, flexible, threadlike appearance. Originally isolated in 1976, the microscopic image of the Ebola virus is now famous, even portrayed in the movie Outbreak. In fact, Ebola's threadlike appearance can vary in both length and degree of twisting, sometimes resembling a bowl of spaghetti.

Explore what it's like inside a patient isolation unit, used in situations such as treating a patient or suspected patient with Ebola.

Cultural norms about how to handle the bodies of loved ones have hampered Ebola responses in West Africa

Awareness of local burial and grieving traditions eventually helped healthcare workers fight the spread of the virus. As healthcare workers and burial teams altered their procedures during the 2014 West African Ebola outbreak, and as community leaders pressed people to adapt traditional ceremonies, the spread of Ebola began to slow.

See the evolution of Ebola vaccine and treatment development

The recently approved vaccine and treatments against Ebola are the result of many years of investments and have reshaped how the world addresses Ebola outbreaks. Four drugs were tested in the midst of the 2014 outbreak. Two proved to be so effective the clinical trial ended early. The vaccine proved effective during the 2018-2020 outbreak in the DRC.

The 2026 Ebola outbreak is hampered by a lack of vaccine against the species of the virus, heightening the need for rapid tests to aid in disease control.

How the most famous Ebola book, The Hot Zone, which sold 3.5 million copies and was translated into 30 languages, got aspects of the disease so wrong.

Watch how viruses like Ebola can spill over from animals to humans—and vice-versa

More than 70% of all new infectious diseases originate in animals. Referred to as zoonotic diseases, these are diseases that originate in animals and occasionally spill over or jump from animals to humans. Bats, mosquitoes, and primates have all been linked to spillover events. As human populations push further into previously uninhabited wilderness, animal-human contact increases, and disease spillover is inevitable.

Marburg virus, related to Ebola, is also extremely deadly, and has no available vaccine.

Rabies is nearly 100% fatal once symptoms appear

Rabies, a viral disease attacking the central nervous system, is nearly always fatal once symptoms appear. It spreads through the infected animal saliva (typically through bites) and causes encephalitis, leading to severe neurological symptoms and death. See how the lyssavirus—the bugs behind rabies—work once inside the body.

Cultural norms about how to handle the bodies of loved ones in communities in West Africa have hampered Ebola responses.

Measles attacks the body’s immune system, leaving it vulnerable to secondary complications

A measles infection begins in the lungs, where it hijacks cells known as macrophages and begins to replicate itself. It then uses a Trojan horse method to enter the lymph nodes, where it attacks vulnerable T and B cells. Symptoms include fever and rashes.

Treating black fever can result in a complication that spreads the deadly disease

Black fever, a deadly parasitic disease second only to malaria, threatens more than 1 billion people across more than 83 countries. Also known as kala-azar or visceral leishmaniasis, the disease is caused by parasites that spread through sandfly...

This is what happens inside your body when you're sick

This video details the biology of what happens inside the human body during illness.

Learn how cholera bacteria sicken humans

Once a person has ingested large amounts of the bacteria, typically through contaminated water, cholera bacteria begin producing and releasing a toxin inside their host. It attacks the mucosal lining of the intestine, making it hard to absorb liquids. This process leads to cholera's characteristic symptoms, like voluminous, watery diarrhea.

See this graphic of the complex malaria transmission lifecycle

Female Anopheles mosquitoes contract malaria by feeding on the blood of a human already infected with the disease-causing parasite. The parasite then develops in the mosquito's gut for one to two weeks before it migrates to the mosquito's salivary glands. Next, when the mosquito bites another person the parasite is delivered into the bloodstream of another human. This graphic further details what happens inside the human body during infection.

Flu spreads through droplets in the air and on surfaces

Influenza passes mainly through tiny droplets released when sick people cough, sneeze or talk. The virus can also survive briefly on surfaces, allowing it to spread when others touch contaminated objects.

How does cancer spread through the body?

Cancer usually begins with one tumor, but it can spread to other organs if not removed. This video breaks down how cancer moves to these new areas and why some organs are more likely to get infected than others.

Receptors on the cell surface are key to whether a virus is successful

Viral receptors are key regulators of host range, tissue tropism, and viral pathogenesis—basically, the door locks on cells allowing viruses to invade, if they have the right key. How this process works at the microscopic level determines whether a virus is able to trigger a widespread illness in the host.

The disease no one survives (yet)

Creutzfeldt-Jakob disease is currently incurable and can cause one's death within months of symptoms appearing. It involves misfolded proteins that, for some reason yet unknown to science, aren't cleared by the brain as typical and instead trigger similar proteins to misfold. These malformed major prion proteins—prion being a portmanteau of protein and infection—clump inside nerve cells, blocking signals crucial to processes ranging from speaking to organ function.

Symptoms of extreme radiation exposure may take hours to manifest

Large doses of ionizing radiation can damage the body within minutes, particularly in the bone marrow and inner layer of the digestive tract. Victims may briefly seem fine before rapidly deteriorating as immune failure, infection and organ collapse set in.

Long-term memory issues among West Nile survivors may be from immune response, not virus

Rodent research suggests that long-term neurological complications such as fatigue, weakness, difficulty walking, and memory loss, may be due to the immune system systematically destroying parts of neurons in the brain in response to the infection, rather than due to viral infection itself.

Sepsis is the leading cause of death in hospitals

Sepsis is the result of an overly aggressive immune system trying to combat infection, triggering inflammation throughout the body. After it begins, each passing hour increases the risk of death by 4% to 9%, and an estimated 350,000 people die from the condition in the US each year.

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

The deadliest aspect of volcanic eruptions is often not lava, but pyroclastic flows—avalanches of ash, gas, and rock that can move more than half the speed of sound.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

Elk Cloner, the first computer virus to spread in public, was written as a practical joke by Richard Skrenta, a Pittsburgh high school student.

Doctors differentiate between a phobia and fear by asking patients whether their fear interferes with their day-to-day activities.

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

Poison ivy's characteristic rash is caused by an allergic response to an oily compound in the plant called urushiol.

US intelligence allegedly pursued more than 600 schemes to assassinate Cuban revolutionary Fidel Castro.

In 1939, baseball star Lou Gehrig delivered his inspirational 'Luckiest Man' speech after retiring due to the health condition that now bears his name.