Priorities for the global surveillance of pathogens in bats

Transcription

1 Priorities for the global surveillance of pathogens in bats Jonathan Epstein DVM, MPH Senior Research Scientist The Consortium for Conservation Medicine Institute of Medicine and National Research Council Global Surveillance Workshop 2008

2 New zoonotic viruses from bats in the last 15 years ear of outbreak/discovery 1994 Hendra virus 1997 Australian fruit bat lyssavirus 1997 Menangle virus 1999 Nipah virus 2001 Tioman virus SARS-like CoV 2005/6* Ebola/Marburg virus 2007 Melaka virus *PCR evidence published

3 Bat Biology Order Chiroptera Most diverse group of mammals > 1000 species 2 sub-orders 1) Microchiroptera -> Insectivorous or sanguiverous (vampire bats) roost in caves or buildings Use echolocation to hunt Some are migratory 2) Megachiroptera -> frugivorous and/or nectivorous roost in caves or trees Use vision and smell to forage migratory Photo: T.kunz Photo: J. Epstein

4 Why are bats such important reservoirs? Many wild animal species may carry potentially zoonotic pathogens what s important is how they connect to people Bats Globally distributed Highly mobile (only volant mammal) Adapted to human environments Share food resources with people (e.g. fruit bats raiding orchards on pig farms (NiV); vampire bats feeding on livestock (rabies)) Share dwellings (bats roosting in ceiling) Photo: J. Epstein

5 New zoonotic viruses from bats in the last 15 years ear of outbreak/discovery 1994 Hendra virus 1997 Australian fruit bat lyssavirus 1997 Menangle virus 1999 Nipah virus 2001 Tioman virus SARS-like CoV 2005/6* Ebola/Marburg virus 2007 Melaka virus *PCR evidence published

6 Lenggong K. Berang 38% (13) Distribution of Nipah virus in Pteropus spp.. in Peninsular Malays P. Kapas 52% (27) 7% (29) Tk. Memali Tanjung Agas 17% (12) 47% (34) Pulau Tioman Muar 13% (52) 38% (26) Benut 58% (24)

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8 Epstein et al., unpublished

9 Model results Repeated spillover demographic parameters Dynamics of initial spillover event are qualitatively different from dynamics of subsequent spillovers Breeding Nucleus infection & disease parameters transmission parameters Epidemic enhancement Introduction into a population with immune individuals larger, longer epidemic Consistent with human case data Total number infected Breeding Section Breeding Section Growing Section Finishing Section Time in days

10 Global Distribution of Henipaviruses in Pteropus spp. Evidence for Henipavirus infection in bats* Confirmed human Henipavirus infection

11 Influenza HIV/AIDS SARS West Nile virus Nipah virus Ebola virus Undiagnosed outbreaks New human infections (e.g. foamy viruses) Wildlife die-offs Silent human infections Unknown pathogens c/o A. Chmura, CCM

12 The Zoonotic Pool (Morse 1993) Assume 50,000 vertebrates, each with 20 endemic viruses (217 in humans). There are likely 1,000,000 vertebrate viruses (bats 20,000 unknown viruses) 99.8% of vertebrate viruses remain to be discovered Large potential for future zoonotic emergence!

13 Global Mammalian Species Richness

14 Smart surveillance - EID Hotspots Hotspots include areas of high biodiversity AND high human population density which may correlate to high connectivity between humans and wildlife Prioritize for surveillance of known / discovery of unknown pathogens in wildlife Jones et al. Nature 2008

15 Global effort to combat EIDs is poorly allocated

16 Challenges of Bat surveillance Difficult terrain often remote Locating colonies often difficult Bats sensitive to disturbance and may leave site Pteropid bats fly higher than treeline Accurate ID of micro or mega bat species often difficult

17 Personal Safety Personal Protective Equipment Long sleeves Eye protection Gloves Respirator (with Pteropus) esp. under roost First aid and exposure protocols Training field team on protocols Rabies (pre-exposure vaccination) Nipah/Hendra

18 Methods of restraint Manual Restraint Appropriate for some species if non-invasive sampling Incr. stress for bat Incr. risk of injury to handler Chemical restraint Anesthesia injectable or inhaled Decreased stress, increased safety Better sample quality Pain management if sampling invasive

19 Sampling Methods Collection of blood; oral and urogenital swabs; feces or fecal swab Serology (ELISA, SNT) Viral Culture (serum, saliva and Urine) Recorded age, condition, pregnant, etc..

20 Conclusions Targeted surveillance: Smart Surveillance Build local lab capacity Standardized methodology. Make central database available to scientists to coordinate future research Understanding the ecology of host species is critical to evaluating risk of zoonotic transmission Photo: J. Westrum

21 Funding NIH/NSF Ecology of Infectious Diseases R01-TW05869 (Nipah virus) Fogarty International Center EF (NSF) (West Nile virus) NIAID Contract NO1-AI Laura Kramer Non-biodefense EID: Bat virus discovery NSF Human & Social Dynamics NIAID training award K08 AI V. Kann Rasmussen Foundation Eppley Foundation, New York Community Trust

22 CCM Jon Epstein Marm Kilpatrick Andrew Taber Collaborators IOZ Kate Jones Columbia Univeristy Ian Lipkin CIESIN Marc Levy ICDDR,B Steve Luby Princeton Andy Dobson Juliet Pulliam CSIRO Bruce Mungall Alex Hyatt Linfa Wang China Hu Zhihong Shuyi Zhang Vincent Deubel Australian Biosecurity CRC Hume Field UCLA Nathan Wolfe

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