Scientists think people are initially infected with Ebola virus 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 a large number of people.
The virus spreads through direct 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, and semen) of a person who is sick with or has died from EVD
- Objects (such as needles and syringes) contaminated with body fluids from a person sick with EVD or the body of a person who died from EVD
- Infected fruit bats or nonhuman primates (such as apes and monkeys)
- Semen from a man who recovered from EVD (through oral, vaginal, or anal sex)
The Ebola virus CANNOT spread to others when a person shows no signs or symptoms of Ebola Virus Disease (EVD). Additionally, Ebola virus is not usually transmitted by food. However, in certain parts of the world, Ebola virus may spread through the handling and consumption of bushmeat (wild animals hunted for food). There is also no evidence that mosquitoes or other insects can transmit Ebola virus.
Persistence of the virus
Ebola virus can remain in certain body fluids after a person has recovered from the infection. These fluids are semen, breast milk, ocular (eye) fluid, and spinal column fluid. Areas of the body that contain these fluids are known as immunologically privileged sites. These are sites of the body where viruses and pathogens, like Ebola virus, can remain undetected even after the immune system has cleared the virus from other sites of the body. Scientists are now studying how long the virus stays in these body fluids among Ebola 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 medical equipment, preferably disposable. Proper cleaning and disposal of instruments such as needles and syringes are important. If instruments are not disposable, they must be sterilized before additional use.
Ebola virus is killed using a U.S. Environmental Protection Agency (EPA)-registered hospital disinfectant [PDF – 278KB] with a label claim for a non-enveloped virus. On dry surfaces, like doorknobs and countertops, the virus can survive for several hours. However, in body fluids, like blood, the virus can survive up to several days at room temperature.
Pets and livestock
Serologic studies show that Ebola virus has been detected in dogs and cats living in areas affected by an Ebola outbreak, but there are no reports of dogs or cats becoming sick with EVD, or spreading the Ebola virus to people or other animals. However, certain exotic or unusual pets (monkeys, apes, or pigs) have a higher risk of being infected with the virus and spreading it, if they are exposed to it.
Pigs are the only species of livestock known to be at risk of infection by an Ebola virus. In the Philippines and China, pigs are naturally infected with Ebola Reston virus, which does not cause illness in people. While pigs have developed illness when infected with an extremely high dose of Ebola virus (Zaire ebolavirus) in a laboratory setting, they are not known to become naturally infected with this virus strain, and there is no indication they are involved in the spread of this virus.
 Allela L, Bourry O, Pouillot R. et al. Ebola Virus Antibody Prevalence in Dogs and Human Risk. Emerging Infectious Diseases. Vol. 11, No. 3, March 2005.
- Page last reviewed: July 22, 2015
- Page last updated: July 22, 2015
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