Ebolaviruses belong to the family Filoviridae and are enveloped viruses with a non-segmented RNA genome of negative polarity with a size of about 18-19 kb. Ebolaviruses are amongst the viruses that can cause a viral hemorrhagic fever (VHF) with high case fatality rates. Thus, ebolaviruses are classified into risk group 4 according to the Ordinance on Biological Substances.
The reservoir host for ebolaviruses is not entirely clear until today. Primates and especially several species of flying foxes and bats are suspected to be mainly responsible for transmission of the virus. Zoonotic transmission of the virus from great apes or bats to humans may occur through physical contact with infected, sick or dead wild animals, e.g. while hunting or consumption of wild animals (“bush meat”). Human-to human transmission mainly occurs through direct contact with blood, organs or body fluids (such as urine, sweat, stoolv vomit) of infected persons.
Until today, ebolavirus infections of livestock have not been observed in Europe. Natural (Reston Ebola virus in the Philippines) and experimental (Ebola virus) infection in swine has confirmed the overall susceptibility of swine for ebolaviruses. After experimental infection of pigs with Ebola virus, respiratory symptoms such as shortness of breath and hyperpnoea as well as fever, loss of appetite and lethargy were the main symptoms. In contrast, experimental infection of pigs with Reston Ebola virus did not cause clinical disease. The susceptibility of dogs is the subject of on-going studies.
In case of appearance of ebolavirus infections in livestock in Germany or Europe, it should be clarified if the agent was introduced by direct import of infected animals (pigs, apes, bats, zoo animals) or by import of animal products from ebolavirus endemic areas.
The current standard to investigate samples submitted from potentially infectious animals at the NRL Ebolavirus is RT-qPCR for genome detection. Further, serological in-house tests are being validated that will allow detection of Ebola virus-specific antibodies (ELISA, indirect immunofluorescence). After commissioning of the BSL4 at FLI, further tests such as virus neutralisation test or virus isolation can now be established and will be used in the future for analysis of samples of suspected cases.