Ecology and evolutionary trajectories of morbilliviruses in Neotropical bats

Bats are important reservoirs of paramyxoviruses, yet their role in the evolutionary origins of viruses pertaining to the paramyxoviral genus Morbillivirus, such as measles virus, remains unclear. Here, combining field surveys and data mining, we identified six divergent morbilliviruses by investigating wild bats (38/1,629 RT-PCR-positive) and non-human primates (NHP, 13/1,370 RT-PCR-positive) in Brazil and Costa Rica over 14 years. High morbillivirus concentrations of up to 10⁹ RNA copies per g and RNA staining in different organs suggested systemic infection. Of 117 vampire bats, 35.9% had neutralizing antibodies against a primary vampire bat morbillivirus isolate, suggesting frequent non-fatal infections. In vitro assays using bat CD150 for cell entry and partial cross-neutralization of bat-associated morbillivirus by heterologous sera suggested conserved entry and antigenicity. NHP-associated, but not bat-associated morbilliviruses, used human CD150 and nectin-4 cellular receptors, suggesting differential zoonotic potential. Macroevolutionary reconstructions revealed predominance of Neotropical bat hosts during morbilliviral diversification, including bat-associated host shifts into Mexican pigs and Brazilian NHPs. These data argue for increased surveillance, experimental risk assessments and intervention strategies to mitigate risks of reservoir-bound morbilliviruses shifting hosts.