Role of swine and dogs in the transmission chain of ebolaviruses

• Applicant: Dr. Sandra Diederich
• Subject Area: Virology
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 426013812

African ebolaviruses have been associated with disease of varying morbidity and mortality in humans. Reston ebolavirus (RESTV), the only ebolavirus species found outside of Africa, can infect humans, but it has never been associated with clinical disease in humans. Recently, a new ebolavirus, Bombali virus (BOMV), was described in insectivorous bats in Sierra Leone, Guinea and Kenya. However, prevalence and pathogenic potential for humans and animals are currently unknown. The zoonotic origin of ebolaviruses has been known for a long time and bats are considered to act as a natural virus reservoir, but the involvement of other animals in the transmission cycle of Ebola virus (EBOV) is still unknown. Emergence of RESTV in pigs in the Philippines raised the question whether pigs may be susceptible to African ebolavirus infection. This led to experimental studies with EBOV demonstrating clinical disease in pigs, transmission to naïve pigs, and importantly to non-human primates housed in the same room. However, the role of pigs in the biology and transmission of ebolaviruses in the natural setting remains unknown. First serological evidence of ebolavirus specific antibodies in pigs from Sierra Leone, Guinea, and Uganda suggests that African pigs have been in contact with and can be infected by ebola- or ebola-like viruses. The involvement of dogs in the community during outbreaks remains elusive. A pilot study demonstrated the presence of EBOV-neutralizing antibodies in dogs suggesting susceptibility to natural infection by EBOV or antigenically related ebolaviruses. However, these data highlight the need for a broader approach including serology and molecular investigations for a risk assessment. Aims of this project are to further assess the role of pigs and dogs in the transmission chain of ebolaviruses and thus, to assist the West African partner countries working towards a detailed risk assessment. In a collaborative approach, we thus plan to sample pigs, dogs and bats from the same area to check for circulating ebolaviruses, and their transmission potential into the livestock or domestic animal population. We further aim to test and implement non-invasive sampling strategies to facilitate safe sampling during future outbreak scenarios. Apart from comparative in vitro studies on virus-host interactions with different eboloviruses, animal studies in pigs are planned that allow analysis of virus shedding and thus, the risk for transmission. Ultimately, this work will provide fundamental data for assessing the involvement of pigs and dogs in ebolavirus biology and thus, determine the risk for spill over events. Overall, this project will strengthen the already established collaboration of FLI with the partner institutions in Guinea and Sierra Leone, but more importantly, support a strong intra-African network.

• DFG Programme: Research Grants
• International Connection: Guinea, Sierra Leone
• Co-Investigators: Professor Dr. Martin Groschup; Dr. Balal Sadeghi
• International Co-Applicants: Roland Suluku, Ph.D.; Noël Tordo