1,361,662 research outputs found
The persistence of a SIR disease in a metapopulation: Hendra virus epidemics in Australian black flying foxes (Pteropus alecto)
No full textUnderstanding how emerging viruses persist in bat populations is a fundamental step to understand the processes by which viruses are transmitted from reservoir hosts to spillover hosts. Hendra virus, which has caused fatal infections in horses and humans in eastern Australia since 1994, spills over from its natural reservoir hosts, Pteropus bats (colloquially known as flying foxes). It has been suggested that the Hendra virus maintenance mechanism in the bat populations might be implicated with their metapopulation structure. Here, we examine whether a metapopulation consisting of black flying fox (P. alecto) colonies that are smaller than the critical community size can maintain the Hendra virus. By using the Gillespie algorithm, stochastic mathematical models were used to simulate a cycle, in which viral extinction and recolonisation were repeated in a single colony within a metapopulation. Given estimated flying fox immigration rates, the simulation results showed that recolonisation occurred more frequently than extinction, which indicated that infection would not go extinct in the metapopulation. Consequently, this study suggests that a collection of transient epidemics of Hendra virus in numerous colonies of flying foxes in Australia can support the long-term persistence of the virus at the metapopulation level.Full Tex
Hendra virus infection dynamics in Australian fruit bats.
Get PDFHendra virus is a recently emerged zoonotic agent in Australia. Since first described in 1994, the virus has spilled from its wildlife reservoir (pteropid fruit bats, or 'flying foxes') on multiple occasions causing equine and human fatalities. We undertook a three-year longitudinal study to detect virus in the urine of free-living flying foxes (a putative route of excretion) to investigate Hendra virus infection dynamics. Pooled urine samples collected off plastic sheets placed beneath roosting flying foxes were screened for Hendra virus genome by quantitative RT-PCR, using a set of primers and probe derived from the matrix protein gene. A total of 1672 pooled urine samples from 67 sampling events was collected and tested between 1 July 2008 and 30 June 2011, with 25% of sampling events and 2.5% of urine samples yielding detections. The proportion of positive samples was statistically associated with year and location. The findings indicate that Hendra virus excretion occurs periodically rather than continuously, and in geographically disparate flying fox populations in the state of Queensland. The lack of any detection in the Northern Territory suggests prevalence may vary across the range of flying foxes in Australia. Finally, our findings suggest that flying foxes can excrete virus at any time of year, and that the apparent seasonal clustering of Hendra virus incidents in horses and associated humans (70% have occurred June to October) reflects factors other than the presence of virus. Identification of these factors will strengthen risk minimization strategies for horses and ultimately humans
Hendra in the Hunter Valley
No full textIn June 2019 the first equine case of Hendra virus in the Hunter Valley, New South Wales, Australia was detected. An urgent human and animal health response took place, involving biosecurity measures, contact tracing, promotion of equine vaccinations and investigation of flying fox activity in the area. No human or additional animal cases occurred. Equine vaccination uptake increased by over 30-fold in the surrounding region in the three months following the case. Black flying fox and grey-headed flying fox species were detected in the Valley. The incident prompted review of Hendra virus resources at local and national levels. This event near the “horse capital of Australia”, is the southernmost known equine Hendra case. Management of the event was facilitated by interagency collaboration involving human and animal health experts. Ongoing One Health partnerships are essential for successful responses to future zoonotic events.Full Tex
The equine Hendra virus vaccine remains a highly effective preventative measure against infection in horses and humans: ‘The imperative to develop a human vaccine for the Hendra virus in Australia’
Get PDFIn their commentary article, ‘The imperative to develop a human vaccine for the Hendra virus in Australia’, Zahoor and Mudie (1) argue the case for a human Hendra virus (HeV) vaccine. The statements supporting their arguments are incorrect and have the potential to cause infection ecology & epidemiology confusion and ultimately undermine confidence in current evidence-based risk management strategies, thereby placing equine and human lives at risk
Hendra virus spillover risk in horses: heightened vigilance and precautions being urged this winter
No full textOn Friday 26 May 2017, Biosecurity Queensland announced that an unvaccinated horse in the Gold Coast hinterland had been euthanased following a positive detection of Hendra virus.1 This was the first Hendra virus case for the year and serves as a reminder to horse owners, veterinarians and allied workers to protect themselves and their animals. Given similarities between current environmental conditions and those that preceded a surge of spillover events in 2011, it may be worthwhile to be especially vigilant this year.Full Tex
Structural studies of Hendra virus replication
No full textTo understand how Hendra virus multiplies in infected cells, we will investigate the structure of its replicative machinery. This will provide the basis for rational drug design increasing Australia’s preparedness against the emergence of Hendra-like viruses.$AUD 306,437.63Targeted CallsUrgent Research - Hendra Viru
Hendra virus
No full textHendra virus is a zoonotic virus, which means it can be transmitted from animals to humans. The natural host of Hendra virus is the flying fox (fruit bat). Occasionally the virus can spread from flying foxes to horses and, rarely, from horses to people.Department of Healt
Hendra virus disease (HeV)
Get PDFHendra virus (HeV) is a member of the family Paramyxoviridae and one of two virus species in the genus Henipavirus (the other being Nipah virus). HeV was first isolated in 1994 from specimens obtained during an outbreak of respiratory and neurologic disease in horses and humans in Hendra, a suburb of Brisbane, Australia.The natural reservoir for Hendra virus has since been identified as the flying fox (bats of the genus Pteropus). Since 1994 and as of 2013, Hendra virus infections in humans remain rare; only seven cases have been reported.Publication date from document properties
Preliminary spatial analysis of Hendra disease outbreaks in South East Queensland
No full textHendra Virus was first reported in the suburb of Hendra, Brisbane in 1994. It has proven to be fatal to both humans and horses, with the first outbreak resulting in the death of 13 horses and a trainer. Since then, there have been several other outbreaks reported across Queensland, from Cairns to the New South Wales border at Murwillumbah. Due to the frequent incidents of the virus outbreak, the Queensland Government's Department of Agriculture, Fisheries and Forestry (DAFF) stated that there is a pressing need for current research on the spatial and temporal occurrences of the virus infections (DAFF 2012). This paper presents an overview of the research, and the preliminary results of the relationship between the Hendra disease outbreaks and the roosting sites of flying-foxes in the south-east Queensland. The results show a strong relationship (92% of the incidents) between temporary and seasonal roosting sites (rather than the permanent continuous roosting sites) and the outbreak locations. This finding suggests the need for detailed cluster analysis and regression models to identify the risk factors for the spread of the disease
Promotion of Hendra virus replication by microRNA 146a
No full textHendra virus is a highly pathogenic zoonotic paramyxovirus in the genus Henipavirus. Thirty-nine outbreaks of Hendra virus have been reported since its initial identification in Queensland, Australia, resulting in seven human infections and four fatalities. Little is known about cellular host factors impacting Hendra virus replication. In this work, we demonstrate that Hendra virus makes use of a microRNA (miRNA) designated miR-146a, an NF-κB-responsive miRNA upregulated by several innate immune ligands, to favor its replication. miR-146a is elevated in the blood of ferrets and horses infected with Hendra virus and is upregulated by Hendra virus in human cells in vitro. Blocking miR-146a reduces Hendra virus replication in vitro, suggesting a role for this miRNA in Hendra virus replication. In silico analysis of miR-146a targets identified ring finger protein (RNF)11, a member of the A20 ubiquitin editing complex that negatively regulates NF-κB activity, as a novel component of Hendra virus replication. RNA interference-mediated silencing of RNF11 promotes Hendra virus replication in vitro, suggesting that increased NF-κB activity aids Hendra virus replication. Furthermore, overexpression of the IκB superrepressor inhibits Hendra virus replication. These studies are the first to demonstrate a host miRNA response to Hendra virus infection and suggest an important role for host miRNAs in Hendra virus disease
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