Effects of biological and environmental factors on filovirus serology in bats in Guinea

BackgroundOutbreaks of Ebola disease emerge regularly in human populations on the African continent. This highly virulent haemorrhagic fever can be caused by different orthoebolaviruses from the Filoviridae family. Several bat species are believed to carry and transmit some of these viruses to people or other animal species. However, clear evidence is still lacking. Natural circulation and zoonotic transmissions of viruses are generally complex as they often involve several host species and are influenced by biological, environmental and anthropogenic factors. A better understanding of the role of bats and other wildlife in the emergence of Ebola disease outbreaks is crucial for their prevention and early detection. MethodsIn this longitudinal study we searched for antibodies against orthoebolaviruses in fruit bats in order to explore some of the factors which might influence their natural circulation. We performed serological tests on populations of 4 bat species (Eidolon helvum, Hypsignathus monstrosus, Myonycteris angolensis and Rousettus aegyptiacus) sampled longitudinally for 18 months (2018-2020) in Guinea. The analysis of 1,427 bat samples for antibodies directed against different orthoebolavirus species allowed us to test the influence of biological and environmental variables on seropositivity by using GLMM. ResultsResults showed that the presence of antibodies against one of the orthoebolaviruses antigen is more frequent in the Eidolon helvum and Rousettus aegyptiacus species, in males, in sexually immature adults, and during the dry season. ConclusionOur results suggest that host species, sex, age, reproductive life-cycle and season may play an important role in the circulation of filoviruses. This information can be used to guide further sampling to specifically characterize the orthoebolavirus species underlying the production of these antibodies and to adjust surveillance protocols at the interface between bats, humans and other animals.