Mucosal Taï Forest virus infection causes disease in ferrets

The filovirus Taï Forest virus (TAFV) caused a single human case of infection originating from a chimpanzee outbreak, demonstrating that humans are susceptible to TAFV infection. Existing animal disease models use intramuscular (IM) infection; however, natural filovirus infection likely occurs mucosal. We aimed to develop a ferret disease model by inoculation of TAFV by the IM, intranasal (IN), or aerosol routes. The IM group showed minimal signs of disease while IN and aerosol inoculations resulted in moderate to severe disease and partial lethality. The surviving IN or IM TAFV-infected ferrets were rechallenged IM or IN with Ebola virus (EBOV) as a pilot study assessing the cross-protection potential between these closely related viruses. Only ferrets IN-inoculated with TAFV and IN-inoculated with EBOV were protected from disease, all others succumbed to disease after EBOV infection. This data shows that ferrets are a feasible model to assess TAFV pathogenicity by mucosal exposure routes and that possible cross-protection between TAFV and EBOV may be achieved upon mucosal exposure.