Identifying Hendra virus diversity in pteropid bats.
Authors: Smith Ina, Broos Alice, de Jong Carol, Zeddeman Anne, Smith Craig, Smith Greg, Moore Fred, Barr Jennifer, Crameri Gary, Marsh Glenn, Tachedjian Mary, Yu Meng, Kung Yu Hsin, Wang Lin-Fa, Field Hume
Journal: PloS one
Summary
# Editorial Summary Hendra virus represents a significant zoonotic threat to equine and human populations, yet our understanding of the virus's natural circulation in its flying fox reservoir has been severely limited by reliance on post-spillover sequences from horses and humans rather than the source population. Smith *et al.* conducted an extensive urine collection programme across multiple Pteropus roosts in Queensland to characterise HeV diversity in bats, identifying numerous circulating variants with distinct nucleotide signatures and hypervariable genomic regions suitable for epidemiological tracking. The researchers detected HeV in bat urine on four separate occasions across three locations, revealing that the virus is geographically widespread with multiple variants co-circulating locally whilst identical strains appeared at distant sites—a pattern suggesting considerable viral movement and persistence within flying fox populations. Critically, the lack of correlation between specific HeV isolates and documented spillover events implies that viral genetics alone do not predict zoonotic transmission, placing emphasis instead on host factors (bat infection status, shedding patterns, population dynamics) and environmental conditions as the primary drivers of equine infection. These findings underscore the unpredictable nature of future spillover events and reinforce the necessity for robust biosecurity protocols around flying fox habitat, continued surveillance of both bat and equine populations, and heightened vigilance during periods of ecological stress that might increase spillover risk.
Read the full abstract on PubMed
Practical Takeaways
- •Hendra virus spillover to horses cannot be predicted based on the viral variant alone; practitioners must maintain vigilance for clinical signs regardless of which variant may be circulating in local bat populations.
- •Ongoing risk management strategies are essential for equine operations in endemic areas, as future spillover events are likely to continue occurring unpredictably.
- •Understanding that environmental and host factors drive transmission rather than viral genetics should inform biosecurity protocols focused on preventing bat-horse contact and monitoring horse health.
Key Findings
- •Hendra virus is geographically widespread in flying fox populations across Queensland with multiple variants circulating simultaneously at different locations.
- •Sequence analysis identified hypervariable regions in the HeV genome that can differentiate between circulating variants.
- •HeV was isolated from flying fox urine on four occasions from three different locations, indicating active viral shedding in natural bat hosts.
- •Spillover events do not correlate with specific HeV isolates, suggesting host and environmental factors are primary determinants of bat-to-horse transmission.