Department of Agriculture, Fisheries and Forestry. Horses, Hysteria and Hendra Bruce Corney

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1 Department of Agriculture, Fisheries and Forestry Horses, Hysteria and Hendra Bruce Corney

2 Outline Hendra The virus The disease Laboratory diagnostics Issues for laboratory Historical (hysterical?) perspective Why the increase in Hendra? 2

Hendra - the virus Family Paramyxoviridae, subfamily Paramyxovirinae, genus Henipavirus SS RNA enveloped virus Fruit bats natural host (asymptomatic

3 Hendra - the virus Family Paramyxoviridae, subfamily Paramyxovirinae, genus Henipavirus SS RNA enveloped virus Fruit bats natural host (asymptomatic carriers) Occasionally spillovers into horses, more rarely from horses to humans Biosafety level 4 virus PC3 laboratory for PCR PC4 laboratory for propagation 3

4 Hendra the disease From flying foxes Infected body fluids and excretions, spats Also horse - to - horse Incubation period 5-16 days Fever, respiratory or neurological signs Usually rapid progression death > 70% mortality Humans through close contact with infected horses (sick or during post mortems) Frequently fatal Horses can shed virus for approximately 2 days before showing symptoms 4

5 Prevention NOT ROCKET SCIENCE Limit potential for exposure of horses to fruit bats or their excretions Keep feed, water troughs and horses away from trees where bats feed or roost Cover feed and water troughs Stable horses during high risk times 5

6 Prevention - We did consider. Would not be well-received by horse owners 6

7 How do we test for Hendra? BSL-4: We can t grow the virus PCR Front-line test for Hendra (current infection status) TaqMan (real-time PCR) Detects genetic material of virus (M gene) Blood plus AT LEAST one swab (nasal, oral, rectal, urine) Not all sites positive simultaneously Indirect ELISA Antibody detection (exposure history) Clotted blood Confirmation by VNT (AAHL) PCR plus serology for Hendra exclusion 7

8 Where do we test for Hendra? QLD testing at BSL Coopers Plains NSW at EMAI Camden Confirmatory testing of positive samples: PCR repeated (late nights!) sent to QHSS Coopers Plains for PCR AAHL Geelong for PCR and Virus Isolation 8

Hendra PCR Template extraction spin columns Move from manual to robotic template extraction QIAGEN EZ1 Advanced XL Rapid Minimal contact with

9 Hendra PCR Template extraction spin columns Move from manual to robotic template extraction QIAGEN EZ1 Advanced XL Rapid Minimal contact with potentially infectious material Low throughput (14 per run) KingFisher 96 Rapid High throughput (96 per run) Magnetic bead technology DNA and RNA 9

10 Issues (laboratory perspective) PCR inhibition Especially blood samples Test extracts neat and diluted Insufficient range of samples (only blood or one swab) Health testing!!! Staffing 2-3 Hendra PCR runs per day during 2011 response Difficulty maintaining normal service Trained extra staff to assist Unrealistic expectations of submitters and others Media Hysteria 10

11 Media 11

12 Historical perspective Spectacular appearance 1994 Hendra QLD stable 13 horses died Horse trainer died Stable worker infected but survived First virus isolation Second appearance October 1995 Human fatality Mackay QLD Necropsied two horses August 1994 Mild undiagnosed infection 1994 fatal encephalitis 14 months later 1995 Retrospectively identified as first spillover Another 12 spillovers

13 Spillovers Date Location Horse cases Human cases/deaths 1994 August Mackay QLD 2 1/ September Hendra QLD 20 2/ January Trinity Beach QLD 1 0/ October Gordonvale 1 1/ December Townsville QLD 1 0/ June Peachester QLD 1 0/ October Murwillumbah NSW 1 0/ June Peachester QLD 1 0/ July Clifton Beach QLD 1 0/ July Redlands QLD 5 2/ July Proserpine QLD 3 0/ July Rockhampton QLD 3 1/ September Bowen QLD 3 0/ May Tewantin QLD 1 0/0 Total 44 7/4 From Marsh et al Emerging Infectious Diseases 16,

14 Spillovers spillovers per year (except 2005) Geographical distribution: 7 North QLD 1 Central QLD 5 South East QLD 1 Northern NSW All Eastern seaboard Temporal distribution 1 January, 1 December (both Northern QLD) 12 June-September 44 horse cases 7 human cases 4 fatalities 14

15 Spillovers 2011 Date Location Horse cases Human cases/deaths June 2011 Beaudesert QLD 1 0/0 June 2011 Boonah QLD 3 0/0 June 2011 Logan Reserve QLD 1 0/0 June 2011 Wollongbar NSW 2 0/0 July 2011 Park Ridge QLD 1 0/0 July 2011 Macksville NSW 1 0/0 July 2011 Kuranda QLD 1 0/0 July 2011 Lismore NSW 1 0/0 July 2011 Hervey Bay QLD 1 0/0 July 2011 Boondall QLD 1 0/0 July 2011 Chinchilla QLD 1 0/0 July 2011 Mullumbimby NSW 1 0/0 August 2011 Ballina NSW 1 0/0 August 2011 South Ballina NSW 2 0/0 August 2011 Mullumbimby NSW 1 0/0 August 2011 Gold Coast hinterland QLD 1 0/0 August 2011 North Ballina NSW 1 0/0 October 2011 Beachmere QLD 2 0/0 Total 24 0/0 15

16 2011 A very different year! QLD 10 spillovers 9 South East 8 Eastern seaboard 1 Darling Downs (Chinchilla) 1 Northern QLD June - October 11 horses died of Hendra 2 horses destroyed 1 dog seroconverted No human infections Dramatic increase in PCR testing 1723 tests June-December tests June-December

17 2011 A very different year! NSW 8 spillovers All Northern NSW (Macksville most Southerly) All Eastern seaboard 10 horses died of Hendra June - August 17

18 Spillovers 2012: January July. More of the same? Date Location Horse cases Human cases/deaths January 2012 Townsville 1 0/0 May 2012 Ingham 1 0/0 May 2012 Rockhampton 1 0/0 June 2012 Mackay 1 0/0 July 2012 Rockhampton 3 0/0 July 2012 Cairns 1 0/0 Total 8 0/0 18

19 2012 More of the same? QLD 6 spillovers to July 31st 2 Central QLD 4 Northern QLD All Eastern seaboard None in South East QLD 8 horse cases 1 person hospitalised 1 in January, then from May onwards None in NSW 19

20 Changing patterns Frequency of spillovers : 14 spillovers 2011: 19 spillovers 2012: 6 spillovers to July 31 st Geographical distribution : Mostly Northern and South East QLD 2011: Mostly South East QLD/Northern NSW 2012: 6 to July 31 st : all Northern and Central QLD Temporal distribution: concentrated May/June - August/September Late Spring - early Autumn 20

21 Why? No definitive answer Do know: Hendra presence and excretion in flying fox colonies is sporadic Pregnancy, lactation, nutritional stress risk factors for infection of flying foxes Environmental factors affect prevalence Unusual wet season 2011 and food supply? Pteropus scapulatus nectivorous, key role in Hendra dissemination among colonies and species Spillovers clustered June - October Excretion by flying foxes has been observed throughout year Factors other than prevalence in colonies 21

22 Acknowledgements BSL Virology Group Craig Smith (QCEID) 22

23 Thank-you Credit: Carol De Jong 23

Bat viruses and diseases

Bat viruses and diseases Lin-Fa Wang CSIRO Livestock Industries Australian Animal Health Laboratory and Australian Biosecurity Cooperative Research Centre for Emerging Infectious Diseases Geelong Vic.