emerging infectious disease

emerging and re-emerging disease

basically, anything we’re worried about

• encounter filter: changing patterns of reservoir host/vector distribution, human contact, …
• compatibility filter: changes via mutation, recombination, selection for resistance, …

Do we need to understand everything?

• reservoir ecology
• pathogen biology
• human-reservoir interactions

How do we understand? How do we predict?

Batrachochytrium dendrobatidis

• fungal pathogen
  • most other chytrids are saprophytes, plant pathogens
  • B. salamandrivorans: salamander pathogen (more restricted)
• first discoved in poison dart frogs
• caused die-offs in E Australia, Central America, Colorado, California …
• association with high altitude?

Very confusing …

• declines occurred in pristine areas (probably not anthropogenic?)

• some species decline in the absence of Bd

• some species stable in the presence of Bd

• tipping point hypothesis: in populations all the time, but something happened to increase virulence/reduce tolerance or resistance (\(\approx\) compatibility filter)

  • climate change/El Niño ?
  • ultraviolet radiation?
  • pesticides?
  • combination (species × temperature × U/V × pesticide × …)? (Pounds et al., 2006; Rohr et al., 2008; Rohr & Raffel, 2010)

• novel pathogen hypothesis: mutation/speciation + dispersal

  • detection in historical specimens: CA/bullfrog, Brazil …
  • genomics (challenging!)
  • Asian sampling

Fisher & Garner (2020)

effects of climate change

• warming
  • ‘good’ or ‘bad’ for pathogens?
  • vector biology
    • extended range
    • higher activity?
    • e.g. Mordecai et al. (2020): shift from Anopheles gambiae to Aedes aegypti, malaria to arboviruses (dengue, chikungunya etc.)
• changes in seasonality, hydrological cycles
• local landscape change
  • hydrology
  • suburbanization and reforestation: Lyme disease
  • deforestation
    • MacDonald & Mordecai (2019): deforestation increases malaria, but malaria decreases deforestation
• changes in reservoir communities

effects of biodiversity change: dilution effect (Keesing & Ostfeld, 2021)

• does increased biodiversity decrease disease?
• variation in reservoir competence
• high-quality hosts decrease with increasing biodiversity
  • encounter reduction; host regulation; vector preferences

Kain & Bolker (2019)

Rohr et al. (2020)

• Carlson et al. (2022): higher rodent diversity and climate anomalies drive plague spillover

surveillance and prediction

• which viruses will emerge, where, why?

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Pulliam & Dushoff (2009): predict zoonotic transmission of livestock viruses

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Walker et al. (2018): predict human transmission ability of zoonotic viruses

Han et al. (2020): model rodent life history

Evans et al. (2023): 2017-2020 sample: 12% of 693 individuals sampled in Myanmar were seropositive for sarbecovirus, more likely if they were loggers/hunters or had been exposed to bats …

References

Carlson, C. J., Bevins, S. N., & Schmid, B. V. (2022). Plague risk in the western United States over seven decades of environmental change. Global Change Biology, 28(3), 753–769. https://doi.org/10.1111/gcb.15966

Evans, T. S., Tan, C. W., Aung, O., Phyu, S., Lin, H., Coffey, L. L., Toe, A. T., Aung, P., Aung, T. H., Aung, N. T., Weiss, C. M., Thant, K. Z., Htun, Z. T., Murray, S., Wang, L.-F., Johnson, C. K., & Thu, H. M. (2023). Exposure to diverse sarbecoviruses indicates frequent zoonotic spillover in human communities interacting with wildlife. International Journal of Infectious Diseases, 0(0). https://doi.org/10.1016/j.ijid.2023.02.015

Fisher, M. C., & Garner, T. W. J. (2020). Chytrid fungi and global amphibian declines. Nature Reviews Microbiology, 18(6), 332–343. https://doi.org/10.1038/s41579-020-0335-x

Han, B. A., O’Regan, S. M., Paul Schmidt, J., & Drake, J. M. (2020). Integrating data mining and transmission theory in the ecology of infectious diseases. Ecology Letters, 23(8), 1178–1188. https://doi.org/10.1111/ele.13520

Kain, M. P., & Bolker, B. M. (2019). Predicting West Nile virus transmission in North American bird communities using phylogenetic mixed effects models and eBird citizen science data. Parasites & Vectors, 12(1), 395. https://doi.org/10.1186/s13071-019-3656-8

Keesing, F., & Ostfeld, R. S. (2021). Dilution effects in disease ecology. Ecology Letters, 24(11), 2490–2505. https://doi.org/10.1111/ele.13875

MacDonald, A. J., & Mordecai, E. A. (2019). Amazon deforestation drives malaria transmission, and malaria burden reduces forest clearing. Proceedings of the National Academy of Sciences, 116(44), 22212–22218. https://doi.org/10.1073/pnas.1905315116

Mordecai, E. A., Ryan, S. J., Caldwell, J. M., Shah, M. M., & LaBeaud, A. D. (2020). Climate change could shift disease burden from malaria to arboviruses in Africa. The Lancet Planetary Health, 4(9), e416–e423. https://doi.org/10.1016/S2542-5196(20)30178-9

Pounds, A. J., Bustamante, M. R., Coloma, L. A., Consuegra, J. A., Fogden, M. P. L., Foster, P. N., La Marca, E., Masters, K. L., Merino-Viteri, A., Puschendorf, R., Ron, S. R., Sánchez-Azofeifa, G. A., Still, C. J., & Young, B. E. (2006). Widespread amphibian extinctions from epidemic disease driven by global warming. Nature, 439(7073), 161–167. https://doi.org/10.1038/nature04246

Pulliam, J. R. C., & Dushoff, J. (2009). Ability to Replicate in the Cytoplasm Predicts Zoonotic Transmission of Livestock Viruses. The Journal of Infectious Diseases, 199(4), 565–568. https://doi.org/10.1086/596510

Rohr, J. R., Civitello, D. J., Halliday, F. W., Hudson, P. J., Lafferty, K. D., Wood, C. L., & Mordecai, E. A. (2020). Towards common ground in the biodiversity–disease debate. Nature Ecology & Evolution, 4(1), 24–33. https://doi.org/10.1038/s41559-019-1060-6

Rohr, J. R., & Raffel, T. R. (2010). Linking global climate and temperature variability to widespread amphibian declines putatively caused by disease. Proceedings of the National Academy of Sciences, 107(18), 8269–8274. https://doi.org/10.1073/pnas.0912883107

Rohr, J. R., Raffel, T. R., Romansic, J. M., McCallum, H., & Hudson, P. J. (2008). Evaluating the links between climate, disease spread, and amphibian declines. Proceedings of the National Academy of Sciences, 105(45), 17436–17441. https://doi.org/10.1073/pnas.0806368105

Walker, J. W., Han, B. A., Ott, I. M., & Drake, J. M. (2018). Transmissibility of emerging viral zoonoses. PLOS ONE, 13(11), e0206926. https://doi.org/10.1371/journal.pone.0206926

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Last updated: 2023-11-30 12:19:32.671124