Hendra Virus Infection Dynamics in the Grey-Headed Flying Fox (Pteropus poliocephalus) at the Southern-Most Extent of Its Range: Further Evidence This Species Does Not Readily Transmit the Virus to Horses.
Authors: Burroughs A L, Durr P A, Boyd V, Graham K, White J R, Todd S, Barr J, Smith I, Baverstock G, Meers J, Crameri G, Wang L-F
Journal: PloS one
Summary
# Editorial Summary Hendra virus remains a significant biosecurity concern for Australian equine industries, yet uncertainty persists regarding which flying fox species serves as the principal reservoir and poses the greatest transmission risk to horses. Researchers intensively sampled a mono-specific grey-headed flying fox colony at the southern limit of its distribution over two years, using pooled urine collection at weekly intervals and a multiplex Luminex platform to detect viral nucleic acids, combined with serological testing of individually trapped animals. Despite detecting four related paramyxoviruses including Cedar virus, no Hendra virus nucleic acid was identified in any pooled urine samples; however, serum antibodies to Hendra were present in 14.6–44.5% of individual bats, indicating prior exposure without active viral shedding at detectable levels in this population. When contextualised alongside northern Australian studies, these findings reinforce growing evidence that black flying foxes, rather than grey-headed flying foxes, are the primary source of spillover events to equine populations. For equine professionals in affected regions, this distinction carries important implications for biosecurity planning: managing paddock exposures and surveillance protocols may be better directed towards areas where black flying fox activity overlaps with horse grazing rather than assuming equal transmission risk from all pteropid species.
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Practical Takeaways
- •Black flying foxes, not grey-headed flying foxes, are likely the primary reservoir responsible for Hendra virus transmission to horses in Australia
- •The absence of active Hendra virus shedding in grey-headed flying fox urine suggests this species poses lower transmission risk despite serological evidence of prior infection
- •Regional variation in Hendra virus epidemiology exists along the Australian east coast, with different flying fox species playing different roles in spillover events
Key Findings
- •All pooled urine samples from grey-headed flying foxes were negative for Hendra virus nucleic acid over a two-year sampling period
- •Serum antibodies to Hendra virus were detected in 14.6-44.5% of individually sampled bats, indicating prior exposure without active shedding
- •Four other paramyxoviruses including Cedar virus were identified in the colony despite absence of Hendra virus
- •Grey-headed flying foxes at the southern extent of their range do not appear to be the principal source of Hendra virus spillover to horses