There are hundreds, if not thousands, of papers published on various research work done on these emerging viruses. I have only uploaded links to a few as evidence of why the Australian Government cannot continue to starve vital funding into finding a vaccine and or cure (post exposure treatment).
Transmission studies of Hendra virus (equine morbillivirus) in fruit bats, horses and cats
Aust Vet J. 1998 Dec;76(12):813-8.
CONCLUSIONS: Grey-headed fruit bats seroconvert and develop subclinical disease when inoculated with HeV. Horses can be infected by oronasal routes and can excrete HeV in urine and saliva. It is possible to transmit HeV from cats to horses. Transmission from P poliocephalus to horses could not be proven and neither could transmission from horses to horses or horses to cats. Under the experimental conditions of the study the virus is not highly contagious.
Full research paper available HERE Bats: Important Reservoir Hosts of Emerging Viruses Charles H. Calisher, James E. Childs, Hume E. Field, Kathryn V. Holmes, and Tony Schountz Full research paper download pdf Reproduction and nutritional stress are risk factors for Hendra virus infection in little red flying foxes (Pteropus scapulatus) Raina K Plowright, Hume E Field, Craig Smith, Anja Divljan, Carol Palmer, Gary Tabor, Peter Daszak and Janet E Foley Full paper download pdf Frontiers in Ecology and the Environment Causal inference in disease ecology: investigating ecological drivers of disease emergence
Raina K. Plowright, Susanne H. Sokolow, Michael E. Gorman, Peter Daszak, and Janet E. Foley
Experimental inoculation study indicates swine as a potential host for Hendra virus
Mingyi LI, Carissa EMBURY-HYATT and Hana M. WEINGARTL Accepted: 18 January 2010
Hendra virus (HeV) is a zoonotic virus from the family Paramyxoviridae causing fatal disease in humans and horses. Five-week-old Landrace pigs and five-month-old Gottingen minipigs were inoculated with approximately 107 plaque forming units per animal. In addition to fever and depression exhibited in all infected pigs, one of the two Landrace pigs developed respiratory signs at 5 dpi and one of the Gottingen minipigs developed respiratory signs at 5 dpi and mild neurological signs at 7 dpi. Virus was detected in all infected pigs at 2-5 dpi from oral, nasal, and rectal swabs and at 3-5 dpi from ocular swabs by real-time RT-PCR targeting the HeV M gene. Virus titers in nasal swab samples were as high as 104.6 TCID50/mL. The viral RNA was mainly distributed in tissues from respiratory and lymphoid systems at an early stage of infection and the presence of virus was confirmed by virus isolation. Pathological changes and immunohistochemical staining for viral antigen were consistent with the tissue distribution of the virus. This new finding indicates that pigs are susceptible to HeV infections and could potentially play a role as an intermediate host in transmission to humans. Full research paper available HERE
Development of an Acute and Highly Pathogenic Nonhuman Primate Model of Nipah Virus Infection
Nipah virus (NiV) is an enigmatic emerging pathogen that causes severe and often fatal neurologic and/or respiratory disease in both animals and humans. Amongst people, case fatality rates range between 40 and 75 percent and there are no vaccines or treatments approved for human use. Guinea pigs, hamsters, cats, ferrets, pigs and most recently squirrel monkeys (New World monkey) have been evaluated as animal models of human NiV infection, and with the exception of the ferret, no model recapitulates all aspects of NiV-mediated disease seen in humans. To identify a more viable nonhuman primate (NHP) model, we examined the pathogenesis of NiV in African green monkeys (AGM). Exposure of eight monkeys to NiV produced a severe systemic infection in all eight animals with seven of the animals succumbing to infection. Viral RNA was detected in the plasma of challenged animals and occurred in two of three subjects as a peak between days 7 and 21, providing the first clear demonstration of plasma-associated viremia in NiV experimentally infected animals and suggested a progressive infection that seeded multiple organs simultaneously from the initial site of virus replication. Unlike the cat, hamster and squirrel monkey models of NiV infection, severe respiratory pathology, neurological disease and generalized vasculitis all manifested in NiV-infected AGMs, providing an accurate reflection of what is observed in NiV-infected humans. Our findings demonstrate the first consistent and highly pathogenic NHP model of NiV infection, providing a new and critical platform in the evaluation and licensure of either passive and active immunization or therapeutic strategies for human use.
CONCLUSION: This is the first demonstration that animals can be infected with EMV by non-parenteral means, that the virus can transmit naturally between animals and confirms other reports of the similarity of EMV disease in horses and cats. Full research paper available HERE
Hendra Virus Mapping - Hendra virus (HeV) was first described in 1994 following the outbreak of a novel disease fatally affecting horses and humans in south-east Queensland. Sporadic outbreaks continue to be identified (in 1999, 2004, 2006, 2007, 2008, 2009 & 2010), with a total of 45+ recognised equine cases (75% CFR) and 7 known human cases (50% CFR) to date.
Fruit bats (flying foxes) have been identified as the natural host of the virus.
The inability to efficiently identify variants circulating in the natural host poses a significant constraint to the development of sensitive diagnostic tests, to response preparedness, and to risk management strategies.
In June 2008, we received WEDPP funding for Stage 1 of an investigation of HeV strain diversity in bats. That study design incorporated both our better understanding of HeV infection dynamics in bats, and sampling and diagnostic approaches to maximize test sensitivity. Our efforts that year yielded the first ever identification of HeV genome in flying fox urine. In 2009, we received joint WEDPP and Australian Biosecurity CRC funding to continue the project, detecting HeV genome in 37 of over 1000 pooled urine samples collected, allowing preliminary comparative phylogenetic analyses of HeV sequence from bat, horse and human, as well as providing insight into the temporal and spatial pattern of HeV infection in flying foxes. Our long-standing collaboration with Dr Linfa Wang’s group at the CSIRO Australian Animal Health laboratory (AAHL) resulted in the isolation of Hendra virus from PCR-positive samples on multiple occasions. The project has also yielded two new (yet to be characterized) paramyxoviruses in flying fox urine.
In 2010 this project was successful in obtaining WEDPP funding to expand investigation of Hendra virus strain diversity in flying foxes to include targeted screening of feral horse and feral pig populations. The WEDPP funding will be augmented by legacy AB CRC funds, as well as in-kind contributions by Biosecurity Queensland and AAHL.
In this proposal, the key research questions are ‘What is the diversity of Hendra viruses occurring in Australia’ and ‘What is the spatio-temporal pattern and frequency of infection in flying fox populations’.
Objectives of this project:
* Identification of the presence or absence of HeV infection in high-risk feral pig and horse populations
* A more complete phylogenetic analysis of Hendra viruses circulating in flying foxes, with this year’s
surveillance targeting previously unsampled locations
* Increased certainty regarding the spatio-temporal pattern of HeV infection in flying foxes. Source: DAFF
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.
Citation: Smith I, Broos A, de Jong C, Zeddeman A, Smith C, et al. (2011) Identifying Hendra Virus Diversity in Pteropid Bats. PLoS ONE 6(9): e25275. doi:10.1371/journal.pone.0025275
Editor: Leo L. M. Poon, University of Hong Kong, Hong Kong Read paper online or download PDF Published 28th September 2011