Robust dengue virus infection in bat cells and limited innate immune responses coupled with positive serology from bats in IndoMalaya and Australasia

On the cell-line side, the authors show that old-world fruitbat cells can be productively infected with dengue virus, producing high titers of progeny virus while inducing only a limited interferon response at multiplicities of infection that drive substantial dengue production. The asymmetry between high viral output and limited innate response is the core mechanistic finding — consistent with bats being a permissive host capable of sustaining replication without disease.

On the serology side, antibody evidence collected from wild bat populations in Asia/Pacific regions documents prior dengue (or closely related flavivirus) exposure in the wild. The combination raises the possibility that bats are at least transient hosts in the life cycle of dengue or other flaviviruses, with implications for spillover dynamics and surveillance design in dengue-endemic regions.

Bats produce virus, not symptoms — and the cell-level mechanism for that asymmetry now has direct evidence. Combining the cell-replication data with positive serology from wild bats in IndoMalaya and Australasia adds bats to the set of plausible flavivirus carriers worth surveilling — important for outbreak preparedness in dengue-endemic regions where bat populations have historically been outside the surveillance focus. For arbovirology and One Health programs, bat cell lines become a tractable mechanistic model for studying flavivirus replication kinetics and innate-response uncoupling, useful for groups that have struggled with the limits of human or rodent cell models for reservoir-host biology.