Identifying Hendra Virus Diversity in Pteropid Bats

Abstract

Hendra virus (HeV) causes a zoonotic disease with high mortality that is transmitted to humans from bats of the genus Pteropus (flying foxes) via an intermediary equine host. Factors promoting spillover from bats to horses are uncertain at this time, but plausibly encompass host and/or agent and/or environmental factors. There is a lack of HeV sequence information derived from the natural bat host, as previously sequences have only been obtained from horses or humans following spillover events. In order to obtain an insight into possible variants of HeV circulating in flying foxes, collection of urine was undertaken in multiple flying fox roosts in Queensland, Australia. HeV was found to be geographically widespread in flying foxes with a number of HeV variants circulating at the one time at multiple locations, while at times the same variant was found circulating at disparate locations. Sequence diversity within variants allowed differentiation on the basis of nucleotide changes, and hypervariable regions in the genome were identified that could be used to differentiate circulating variants. Further, during the study, HeV was isolated from the urine of flying foxes on four occasions from three different locations. The data indicates that spillover events do not correlate with particular HeV isolates, suggesting that host and/or environmental factors are the primary determinants of bat-horse spillover. Thus future spillover events are likely to occur, and there is an on-going need for effective risk management strategies for both human and animal health.

The relationship between physiological stress and wildlife disease: consequences for health and conservation

“…The epidemiology of HeV remains incompletely understood, particularly the host and environment factors driving spill-over events (Hyatt et al 2004;Smith et al 2011). Changes in flying fox ecology associated with anthropogenic stressors including climate change, habitat fragmentation and urbanisation, have been proposed as drivers of HeV disease dynamics (Bradley and Altizer 2007;Plowright et al 2011;Dietrich et al 2015).…”

Henipaviruses: bat-borne paramyxoviruses

“…the Black flying fox (Pteropus alecto), Grey-headed flying fox (P. poliocephalus), Spectacled flying fox (P. conspicilla-tus) and the Little red flying fox (P. scapulatus) 9,22 . Further research has resulted in isolation of HeV directly from pteropid bats 23,24 .…”

Investigating risks to Australia of emergent henipaviruses

“…The presence of Hendra virus has been confirmed by viral isolation from P. alecto, P. poliocephalus and P. conspicillatus from Australia (Halpin et al, 2000;Smith et al, 2011), and is apparent based on serology in P. scapulatus in Australia and P. hypomelanus, P.…”

“…Despite this effort, there are few published accounts of isolation of henipaviruses from wild bats. These include: three isolates of HeV from Pteropus poliocephalus; four isolates of HeV from Pteropus alecto (Halpin et al, 2000;Smith et al, 2011); one isolate of HeV from Pteropus conspicillatus ; and single isolates of NiV from Pteropus hypomelanus, Pteropus lylei and Pteropus vampyrus Rahman et al, 2010).…”