Ebola disease is a severe disease caused by infection with the Ebola virus and leading to severe and often fatal hemorrhagic fever in humans.
Ebola virus belongs to the genus Ebolavirus and its genome is a single-stranded RNA approximately 19,000 nucleotides long, encoding seven structural proteins which assemble with the genomic RNA to form one of the deadliest viruses.
The disease was first discovered in 1976 in Democratic Republic of Congo near to Ebola River with 318 cases and a case fatality ratio of 88%, being one of the most deadly outbreak in recent history. The most recent outbreak started in March 2014 in Guinea, followed by the surrounding regions of Sierra Leone, Nigeria and Liberia.
The virus origin remains unclear, but it is believed to be a zoonotic disease (an animal disease that can spread to humans). The natural source of infection of the Ebola virus remains unknown. However, fruit bats are the suspected natural hosts that transmit the virus to other animals such as monkeys, gorillas and chimpanzees. Scientists think people were initially infected with Ebola virus through contact with infected animals, such as a fruit bat or nonhuman primate.
Ebola virus: transmission
The Ebola virus is mainly spread in the blood, organs or body fluids of an animal or person with the infection. Therefore, the infection spreads to people through direct contact with bodily fluids of a person who is infected with ebola or people who died from ebola virus disease. For example, when a person touches objects or body fluids are contaminated, and the virus gets in through skin with cuts or abrasions or mucous membranes in the mouth, nose or eyes.
Ebola virus: symptoms
Signs and symptoms of ebola infection typically begin abruptly within 2 to 21 days of infection with the virus. Signs and symptoms include:
- Severe headache
- Joint and muscle aches
- Abdominal pain
- Unexplained haemorrhage
Many other common viral infections can have these some of the same symptoms, including influenza.
Ebola virus: prevention
Different preventive measures are recommended for people in an area affected by an outbreak:
- Wear protective clothing including masks, gloves, gowns and goggles
- Use disposable equipment and supplies when possible
- Practise careful hygiene
- Avoid contact with blood and body fluids
- Avoid funeral or burial rituals requiring handling the body of infected people
- Avoid contact with non-human primates and bats and body fluids or meat
- Isolate suspected patients if possible