Natural Hendra Virus Infection in Flying-Foxes - Tissue Tropism and Risk Factors.
Authors: Goldspink Lauren K, Edson Daniel W, Vidgen Miranda E, Bingham John, Field Hume E, Smith Craig S
Journal: PloS one
Summary
# Editorial Summary: Hendra Virus Tissue Distribution in Flying-Foxes Flying-foxes are the natural reservoir for Hendra virus, a zoonotic pathogen responsible for 51 documented spillover events to horses since its emergence in 1994, with seven subsequent human infections. Researchers screened archived tissues from 310 bats (295 pteropid and 15 vespertilionid species) using reverse transcription quantitative polymerase chain reaction, detecting HeV in 20 flying-foxes (6.4%) across multiple organs including spleen, kidney, liver, lung, blood and placental tissues. Two species—*Pteropus alecto* and *P. conspicillatus*—showed significantly higher infection rates, establishing them as higher-risk reservoir populations; moreover, the spleen emerged as the primary target organ, suggesting it plays a critical role in viral persistence and replication. The absence of HeV detection in foetal tissues of infected females indicates that vertical transmission is not a significant route of transmission in naturally infected bats, meaning pregnant females and their unborn offspring are unlikely to be major sources of equine exposure. For equine practitioners and farm managers, these findings refine understanding of spillover mechanisms and suggest that surveillance efforts and biosecurity protocols should account for species-specific infection patterns and the limited role of reproductive tissues in transmission cycles.
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Practical Takeaways
- •Properties of flying-fox species around your facility matter—P. alecto and P. conspicillatus carry higher HeV loads; implement species-specific biosecurity measures accordingly
- •Focus on preventing spleen tissue contact (through carcass handling and feed contamination prevention) as this organ has highest viral burden and spillover risk
- •Pregnant mares and foals show lower spillover risk from flying-fox exposure since vertical transmission in bats is rare and foetal tissues are not major infection sources
Key Findings
- •Hendra virus detected in 6.4% (20/310) of flying-foxes screened, predominantly in spleen, kidney, liver, lung and blood components
- •Pteropus alecto and P. conspicillatus species showed significantly higher HeV detection rates compared to other bat species
- •Spleen identified as primary tissue with HeV predilection, suggesting central role in viral infection
- •Foetal tissues from HeV-positive females tested negative, indicating vertical transmission is not a regular transmission route and placental tissue unlikely a major infection source for spillover to horses