Patterns of RNA virus infection and transmission within a wild simian zoonotic reservoir in Uganda

James Lester

KEP University of Cambridge

The context of viral transmission in Kibale National Park

  • KNP a 776 km2 area of protected forest
  • Diverse primate community
  • Of great conservation, and potential zoonosis interest

(Figure: Lessons about parks and poverty from a decade of forest loss and economic growth around Kibale National Park, Uganda, Naughton-Treves et al, 2011)

VirAge

Our reservoir of interest - Kibale red colobus

  • Especially sensitive to environmental change
  • Live in multi-male groups of 19-80 individuals
  • Predated by chimps
  • Known hosts of SIV, SFV, SPgV and SHFV1/2

VirAge

Viruses of interest: SIV and SFV

  • SIV
    • Considerable variation in prevalence between populations, fluid transmission
    • Relatively low prevalences identified within Kibale RCB, as opposed to Taï and others

    • Associated with dominance rank in sooty mangabeys
  • SFV
    • Consistently observed at high prevalence within RCB populations, salivary transmission
    • Maternal clustering identified within chimpanzees

Viruses of interest: SHFV(1/2) and SPgV

  • SHFV(1/2)
    • Only recently identified in the wild, no previous epidemiology
    • Previously involved in research facility outbreaks, able to readily spread amongst infected hosts, not airborne
  • SPgV
    • Similarly, only recently identified within wild-living primates, no previous epidemiology
    • Has a human analog - HPgV
    • Associated with presence of other blood-borne or sexually transmitted infections
    • Vertical transmission, either prenatal or during birth

Our approach

  • Deep sequencing of blood samples from two red colobus troops
    • Allowing us to obtain full-length genomes for SHFV(1/2) and SPgV
    • Alongside clear identification of coinfections
    • Able to use sequencing not just as a diagnostic tool, but also to cluster infections
  • Monthly behavioural scans for one of these groups over several consecutive days, with one focal red colobus troop
  • Microsatellite data for each sampled individual

Our approach (cont.)

VirAge

Key questions

  • What are the demographic correlates of infection with these viruses?
  • Do they associate with each other?
  • Does infection with these viruses relate to patterns of behaviour?
  • Can viral clustering be related to this?

Correlates of infection

VirAge

Patterns of coinfection

ORCoinf

Patterns of infection clustering

InfClust

Behavioural correlates of infection

ORCoinf

Behavioural correlates of infection clustering

ORCoinf

Conclusions

  • Indications of age-associated accumulation of infection in certain contexts - Particularly females
  • Indications of both horizontal and (more tentatively) vertical transmission
  • Co-infection with only the SHFV viruses indicated
  • Association between agonistic, copulatory and associative behaviour and SHFV infection, not so for SPgV and SIV

Remaining questions and further work

  • Low prevalence of SIV, and lack of association with dominance
  • High SPgV prevalence with no association with dominance - Patterns of recovery and immunity?
  • Why SHFV relates so strongly to patterns of agonism and other indications of social dominance?
  • Requires further analysis of within-sample viral diversity
  • Longitudinal viral sampling, for molecular clock calibration and potential dating of divergence

Acknowledgements

University of Cambridge

  • Simon Frost
  • Bethany Dearlove

University of Madison-Wisconsin

  • Tony Goldberg
  • Sam Sibley

Stanford University

  • James Holland Jones

CDC

  • William M. Switzer

McGill University

  • Colin Chapman

University of Oregon

  • Nelson Ting
  • Maria Jose Ruiz-Lopez

Makerere University

  • Geoffrey Weny
  • David Hyeroba
  • Alex Tumukunde

Funding

  • ESRC
  • NIH

ESRC NIH KEP