Genetic Variability of West Nile Virus in US Blood Donors, 2002–2005
2008

Genetic Variability of West Nile Virus in US Blood Donors, 2002–2005

Sample size: 30 publication Evidence: moderate

Author Information

Author(s): Grinev Andriyan, Daniel Sylvester, Stramer Susan, Rossmann Susan, Caglioti Sally, Rios Maria

Primary Institution: Food and Drug Administration

Hypothesis

How has the genetic variability of West Nile Virus changed in US blood donors from 2002 to 2005?

Conclusion

The study found that West Nile Virus has continued to diverge from precursor isolates as its geographic distribution has expanded, with a small increase in genetic diversity over the years.

Supporting Evidence

  • West Nile virus was first detected in the US in 1999 and has become endemic.
  • Transfusion transmission of WNV was documented in 2002.
  • Genetic diversity in WNV isolates was observed from different geographic regions.
  • Nucleotide divergence of structural genes increased from 0.18% in 2002 to 0.37% in 2005.
  • 80% of nucleotide changes in structural regions were transitions and 75% were silent mutations.

Takeaway

Scientists looked at blood samples from people infected with West Nile Virus and found that the virus is changing a little bit over time as it spreads across the country.

Methodology

The study analyzed complete genomic sequences of 8 isolates and structural gene sequences from 22 additional isolates obtained from 30 infected blood donors.

Limitations

The study was limited by the small number of fully sequenced isolates and the potential for mutations during viral isolation.

Participant Demographics

Blood donors from 13 states in the continental United States.

Digital Object Identifier (DOI)

10.3201/eid1403.070463

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