ebola

Ebola, also known as Ebola virus disease (EVD), is a type of hemorrhagic fever. It is a rare and often deadly disease. It can be caused by several different types of Ebola viruses. There are occasional outbreaks of Ebola, and they mostly occur in Africa.

Researchers believe that the virus first spreads from an infected animal to a human. Ebola can then spread from human to human through direct contact with:

• Blood or body fluids of a person who is sick with or has died from Ebola.
• Objects (such as clothes, bedding, needles, and medical equipment) contaminated with body fluids from a person who is sick with or has died from Ebola.
• Semen (through oral, vaginal, or anal sex) from a man who has recovered from Ebola. The virus can remain in semen and other body fluids, even if the person no longer has symptoms.

When people become infected with Ebola, they do not start developing signs or symptoms right away. They cannot spread Ebola to others until after they develop symptoms.

The symptoms of Ebola may appear anywhere from 2 to 21 days after exposure to the virus. The average is about 8 to 10 days. The symptoms usually include:

• Fever
• Headache
• Joint and muscle aches
• Weakness and fatigue
• Sore throat
• Gastrointestinal symptoms including abdominal (belly) pain, diarrhea, and vomiting
• Loss of appetite
• Unexplained bleeding or bruising

Other symptoms may include a rash, red eyes, and hiccups.

The early symptoms of Ebola are similar to other more common diseases. This makes it difficult to diagnose Ebola in someone who has been infected for only a few days. If a person has the symptoms of Ebola and may have been exposed to the virus, the health care provider can do a blood test for Ebola. It can take a few days after the symptoms start before Ebola shows up in the blood test.

In the United States, there are two approved medicines to treat Ebola that is caused by one specific type of virus (Zaire ebolavirus). These medicines have not been evaluated to treat Ebola caused by other types of Ebola viruses. The medicines are monoclonal antibodies, which are immune system proteins that are created in the lab.

Whether or not there are medicines to treat a case of Ebola, there is supportive care. This type of care can improve the chances of survival, especially when given early. Supportive care includes:

• Giving fluids and electrolytes
• Giving medicines to support blood pressure, reduce vomiting and diarrhea, and to manage fever and pain
• Giving oxygen
• Treating any other complications or infections

People who recover may still have side effects afterwards, such as fatigue, muscle aches, eye and vision problems, and stomach pain.

In the United States, there is one vaccine that has been approved to prevent Ebola caused by one specific type of Ebola virus (Zaire ebolavirus). It may be given to health care providers who will be or may be treating Ebola patients and people who work with live Ebola virus in labs.

If you live in or plan to travel to a region where Ebola virus may be present, you can help protect yourself by avoiding contact with:

• Blood and body fluids of people who are sick
• Semen from a man who has recovered from Ebola, until testing shows that the virus is gone from his semen
• Items that could be contaminated with blood or body fluids from someone who has Ebola
• Bats, forest antelopes, and nonhuman primates (such as monkeys and chimpanzees), including their blood, fluids, or meat

Centers for Disease Control and Prevention

Viral hemorrhagic fevers (VHFs) are a group of illnesses caused by four families of viruses. These include the Ebola and Marburg, Lassa fever, and yellow fever viruses. VHFs have common features: they affect many organs, they damage the blood vessels, and they affect the body's ability to regulate itself. Some VHFs cause mild disease, but some, like Ebola or Marburg, cause severe disease and death.

VHFs are found around the world. Specific diseases are usually limited to areas where the animals that carry them live. For example, Lassa fever is limited to rural areas of West Africa where rats and mice carry the virus.

The risk for travelers is low, but you should avoid visiting areas where there are disease outbreaks. Because there are no effective treatments for some of these viral infections, there is concern about their use in bioterrorism.

Centers for Disease Control and Prevention

A bioterrorism attack is the deliberate release of viruses, bacteria, or other germs to cause illness or death. These germs are often found in nature. But they can sometimes be made more harmful by increasing their ability to cause disease, spread, or resist medical treatment.

Biological agents spread through the air, water, or in food. Some can also spread from person to person. They can be very hard to detect. They don't cause illness for several hours or days. Scientists worry that anthrax, botulism, Ebola and other hemorrhagic fever viruses, plague, or smallpox could be used as biological agents.

Biodefense uses medical measures to protect people against bioterrorism. This includes medicines and vaccinations. It also includes medical research and preparations to defend against bioterrorist attacks.

Centers for Disease Control and Prevention

Viruses are very tiny germs. They are made of genetic material (either DNA or RNA) inside of a protein coating. There are a huge number of viruses on earth. Only a small number of them can infect humans. Those viruses can infect our cells, which may cause disease. Some of the diseases that viruses can cause include the common cold, the flu, COVID-19, and HIV.

Viruses can be spread in different ways:

• Through droplets and particles that are breathed out by someone who has the infection. You might breathe in the droplets or particles, or they could land on your mouth, nose, or eyes.
• By touching surfaces or objects that have the virus on them and then touching your mouth, nose, or eyes.
• From the pregnant parent to the baby during pregnancy.
• Through contaminated food or water.
• By being bitten by an infected insect or animal.
• Through sexual contact (usually vaginal, anal and oral sex) with someone who has the infection.

Viruses are like hijackers. They invade living, normal cells. They then use those cells to multiply (make copies of themselves). This process is also called replication. The process can kill, damage, or change the infected cells. Sometimes this can make you sick. The symptoms can range from mild to very severe. Other times, your immune system may be able to fight it off and you may not have any symptoms.

Each different virus usually only infects one type of cell in your body. For example, hepatitis viruses affect the cells in the liver. HIV infects a certain type of immune system cell.

For most viral infections, treatments can only help with symptoms while you wait for your immune system to fight off the virus. There are antiviral medicines to treat some viral infections. Antibiotics do not work for viral infections.

Vaccines can help prevent you from getting many viral diseases. You may be able to prevent some viral infections by:

• Proper hand washing.
• Paying attention to food safety.
• Cleaning surfaces that may be infected with germs.
• Avoiding contact with wild animals.
• Preventing insect bites by using insect repellent when you go outdoors. If you travel to an area that has a high risk of diseases from insect bites, also wear long pants, shirts, and socks.
• Practicing safe sex (using a condom every time you have anal, vaginal, or oral sex).
• Avoiding close contact with people who are sick.