Ebola Virus Disease (EVD) is a severe and often fatal illness that affects humans and non-human primates. It is caused by viruses belonging to the Ebolavirus genus within the Filoviridae family. Ebola is a zoonotic disease, meaning its initial introduction into human populations typically originates from contact with infected animals.
Ebola’s Animal Connection
Ebola virus is believed to have a natural reservoir in certain animal species, with fruit bats (Pteropodidae family) being the most suspected hosts. These bats can carry the virus without showing signs of illness, allowing them to maintain the virus in nature. The virus can then spread to other animals, which act as intermediate hosts before potentially infecting humans.
Non-human primates (such as chimpanzees, gorillas, and monkeys) and forest antelopes (like duikers) are examples of animals that can become infected with Ebola. These animals often contract the virus through contact with infected bats or their bodily fluids, such as consuming fruit contaminated by bat saliva or feces. When these intermediate hosts become sick, they can then transmit the virus to humans.
Spillover events, where the virus jumps from animals to humans, frequently occur through direct contact with infected wild animals or their bodily fluids. This includes handling or consuming infected bushmeat (e.g., monkeys, apes, or forest antelopes). Contact with infected bats or their droppings, particularly in caves or mines, also poses a risk for transmission.
How Ebola Spreads Between People
Once Ebola jumps from an animal to a human, it can spread person-to-person. This human-to-human transmission occurs through direct contact with the blood, secretions, organs, or other bodily fluids of an infected person. Bodily fluids that can transmit the virus include urine, feces, vomit, saliva, sweat, tears, breast milk, and semen.
Transmission can also occur indirectly through contact with objects contaminated with infectious fluids, such as soiled clothing, bedding, or medical equipment like needles. Traditional burial practices, which may involve direct contact with the body of someone who has died from Ebola, can further contribute to the spread of the disease.
People generally become infectious only after they start to develop symptoms of Ebola. While the virus is not typically spread through the air, it can persist in certain bodily fluids, such as semen, for months or even longer after a person has recovered, posing a risk for sexual transmission.
Stopping Zoonotic Transmission
Preventing zoonotic spillover (the initial jump of Ebola from animals to humans) is a focus of public health efforts. Avoid direct contact with wild animals, especially fruit bats, non-human primates, and forest antelopes, in regions where Ebola is known to occur. This includes refraining from touching live or dead animals, their meat, or their bodily fluids.
Safe handling and preparation of meat products, particularly bushmeat, are crucial. Thoroughly cooking meat and practicing good hygiene when handling raw meat can help reduce the risk of transmission. Avoiding consumption of raw or undercooked meat from wild animals is a recommended preventative step.
Public health awareness campaigns educate communities in affected areas about these risks. Promoting practices such as washing hands frequently with soap and water or using alcohol-based hand sanitizer can also help minimize the chance of infection. These collective efforts aim to interrupt the pathway of the virus from its animal hosts to human populations.