What are “viral spillover risks”?

A new research found that climate change could increase the risk of “viral spillover” in several parts of the world. This could cause pandemics in the future.

Key facts

  • A new research article titled “Viral spillover risk increases with climate change in High Arctic lake sediments” was released recently.
  • Viral spillover occurs when viruses overcome several barriers to infect new host from reservoir host (in which it usually resides).
  • The researchers from the University of Ottawa sought to study the possibility of a viral spillover by collecting sediments and soil samples from Lake Hazen in Canada – the world’s largest High Arctic lake by volume.
  • High Arctic was chosen for this study since it is warming faster than the rest of the world.
  • The researchers sequenced the RNA and DNA to reconstruct the lake area’s virus composition and estimated the viral spillover risks.
  • The study found that the chances of viruses successfully infecting new host increases with the runoff from glacier melt.
  • With global warming increasing the instances of glacier melting, there is a high possibility of previously ice-trapped viruses and bacteria finding new hosts and increasing spillover risks.
  • Spillover risks are also increased due to changes in global distribution and dynamics of the viruses, their reservoirs and vectors.
  • However, this does not guarantee a higher possibility of pandemic occurring in the future.
  • This is because viral spillover depends on three main categories – pathogen pressure, human and vector behaviors and attributes of the host.
  • All these phases are fraught with several natural challenges that the virus must overcome to successfully reach the new host.
  • Coronaviruses successfully overcame these barriers since they are RNA viruses capable of evolving more quickly than other virus families because of their ability to recombine and acquire point mutations.
  • Other pathogens that have successfully spilled over to humans are Influenza A and Ebola.



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