Ebola (Ebola fever) is a rare and life-threatening infectious disease that is caused by the Ebola virus and is particularly prevalent south of the Sahara. The Ebola virus belongs to the Filoviridae family. Ebola viruses belong to five species, all of which are enveloped viruses. The original natural host of the Ebola virus is the fruit bat. The virus first appeared in humans in 1976, when the disease spread along the banks of the Ebola River in Congo, which the pathogen was then named after. At that time, almost all the people who came into contact with the virus died. The largest Ebola epidemic to date spread to West Africa beginning March 2014. It was not until early 2016 that the WHO declared it over. Most recently, the epidemic flared up again in the Congo in August 2018.
Infected wildlife was probably the origin of the last major Ebola epidemic. When people come into contact with the animals’ flesh, blood or other body secretions, they can also become infected. Bats and apes – whose meat is still to some extent a source of food in West Africa – are the most common sources of pathogens. Once the virus has been transmitted to humans, it is spread among the population through direct contact with blood, saliva, vomit, stool or urine from sick or deceased people. Contaminated everyday objects such as needles, clothing, bed linen or surgical instruments are also considered possible virus transmitters. However, there is only a risk of infection from people who show signs of illness.
The symptoms of an Ebola infection are initially similar to those of influenza. As the disease progresses, the infected person may develop the dangerous haemorrhagic fever that causes internal bleeding. The incubation period of Ebola fever can be between two and 21 days. On average, however, the first symptoms appear after eight to nine days. At the beginning of the disease, those affected show symptoms such as fever, discomfort, fatigue and aching limbs. As the disease progresses, vomiting and diarrhoea, redness of the conjunctiva, headache, chest pain, difficulty swallowing, internal and external bleeding, delirium and shortness of breath may also occur. The virus triggers what is known as haemorrhagic fever: Blood vessels become permeable, dark effusions spread under the skin. In 30% to 90% of cases, the infection is fatal.
In affected sub-Saharan Africa, Ebola infections are common in hospitals that already treat Ebola patients. This is mainly a result of the often poor local hygiene conditions, inadequate supply of disinfected/sterilised materials and the multiple use of surgical instruments and syringes. Where sufficient hygiene and quarantine measures were available, the spread of the pathogen could be contained.
On dry surfaces such as metal or plastic under tropical conditions (27°C, 80% humidity): 3 to 4 days; under climate conditions such as those found in a hospital (21°C, 40% humidity): 7 to 14 days
The necessary spectrum of activity against Ebola viruses is: limited virucidal