Scientists think people are initially infected with an ebolavirus through contact with an infected animal, such as a fruit bat or nonhuman primate. This is called a spillover event. After that, the virus spreads from person to person, potentially affecting many people.
Ebolaviruses spread through contact (such as through broken skin or mucous membranes in the eyes, nose, or mouth) with:
- Blood or body fluids (urine, saliva, sweat, feces, vomit, breast milk, amniotic fluid, and semen) of a person who is sick with or has died from Ebola disease.
- 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 disease.
- Infected fruit bats or nonhuman primates (such as apes and monkeys).
- Semen from a man who recovered from Ebola disease (through oral, vaginal, or anal sex). Ebolaviruses can remain in certain body fluids (including semen) of a patient who has recovered from Ebola disease, even if they no longer have symptoms of severe illness. There is no evidence that ebolaviruses can spread through sex or other contact with vaginal fluids from a woman who has had Ebola disease.
When people become infected with an ebolavirus, they do not start developing signs or symptoms right away. This period between exposure to an illness and having symptoms is known as the incubation period. A person can only spread an ebolavirus to other people after they develop signs and symptoms of Ebola disease.
Additionally, ebolaviruses are not known to be transmitted through food. However, in certain parts of the world, ebolaviruses may spread through the handling and consumption of wild animal meat or hunted wild animals infected with an ebolavirus. There is no evidence that mosquitoes or other insects can transmit ebolaviruses.
- Health workers and family members who do not use proper infection control while caring for patients with suspected or confirmed Ebola disease are at the highest risk of getting sick. Ebolaviruses can spread when people come into contact with infected blood or body fluids.
- Ebolaviruses pose little risk to travelers or the general public who have not cared for or been in contact with someone sick with Ebola.
Persistence of Ebolaviruses
Ebolaviruses can remain in areas of the body that are immunologically privileged sites after acute infection. These are sites where viruses and pathogens, like ebolaviruses, are shielded from the survivor’s immune system, even after being cleared elsewhere in the body. These areas include the testes, interior of the eyes, placenta, and central nervous system, particularly the cerebrospinal fluid. Whether an ebolavirus is present in these body parts and for how long varies by survivor. Scientists are now studying how long ebolaviruses stay in these body fluids among Ebola disease survivors.
During an Ebola outbreak, the virus can spread quickly within healthcare settings (such as clinics or hospitals). Clinicians and other healthcare personnel providing care should use dedicated, preferably disposable, medical equipment. Proper cleaning and disposal of instruments such as needles and syringes are important. If instruments are not disposable, they must be sterilized before using again.
Ebolaviruses can survive on dry surfaces, like doorknobs and countertops for several hours; in body fluids like blood, ebolaviruses can survive up to several days at room temperature. Cleaning and disinfection should be performed using a hospital-grade disinfectant.
In the United States, hospital-grade disinfectant refers to U.S. Environmental Protection Agency (EPA)-registered hospital disinfectant [PDF – 278 KB] with a label claim for a non-enveloped virus.