Serological evidence of exposure to filoviruses and henipaviruses in wildlife, Malaysia

Purpose: PCR and serological-based approaches have been used to identify henipavirus and filovirus (e.g. Nipah virus, Ebola virus) exposure or infection in bat populations in Bangladesh, China, and Southeast Asia. Our understanding of the diversity of these viruses in bat reservoirs, and the frequency of spillover to other animals or people, is extremely limited. We hypothesized that henipaviruses and filoviruses were circulating within multiple bat reservoirs and that spillover of these viruses to non-human primate populations has occurred in Malaysia. Methods & Materials: We utilized a multiplex serological assay to screen sera for reactive IgGs that bound to antigens from henipaviruses and filoviruses. We produced virus attachment glycoproteins (GP) from sixteen virus species in the families Paramyxoviridae and Filoviridae. As part of our ongoing collaboration, we conducted in-country assay training and sera testing at the Department of Wildlife and National Parks, National Wildlife Forensic Laboratory. We screened sera from eight bat genera and sera from Macaca fascicularis populations. Results: Sera samples from Pteropus hypomelanus (n = 56) were reactive with Nipah virus GP (25%) and cross-reactive with GPs from closely-related henipaviruses. In these same P. hypomelanus samples we detected reactivity with Ebola virus and Sudan virus GPs (10% and 5%, respectively). Sera from several Hipposideros species and P. hypomelaus reacted with the Henipavirus species, Mojiang virus GP. Two M. fascicularis sera samples reacted with GPs from Ebola virus and Bundibugyo virus and M. fascicularis sera samples specifically reacted with Mojiang virus; all four samples exhibited median fluorescence intensity values > 10,000. We also detected reactivity to Ebola virus and Sudan virus GPs in sera samples collected from Hipposideros, Cynopterus and Rhinolophus species. We did not detect any samples that were reactive with Reston virus GPs. Conclusion: We detected evidence of past exposure to virus(es) most antigenically-similar to Ebola virus, Bundibugyo virus, and Sudan virus in sera samples from bat and non-human primate populations collected in Malaysia. This is also the first sero-survey for Mojiang virus and the first evidence of exposure to Mojiang virus in bats and non-human primates. Our results suggest that there are different but antigenically related henipaviruses and filoviruses circulating in bats in Malaysia.