The West Nile virus invasion

West Nile virus was first detected in the United States in 1999 (New York), and within a few years, the virus spread across the country. Now, West Nile virus is endemic and has become the most important mosquito-borne virus threat in the United States. Yet, little progress has been made in controlling outbreaks, due in part to a declining interest in West Nile virus research. Thus, for future targeted control measures to be developed, there is a critical to explore the diversity of circulating West Nile viruses and how this may influence the emergence of new virus strains that cause disease outbreaks.


High-definition West Nile virus phylogenetics

We are organizing a large West Nile virus phylogenetics study to answer some fundamental questions about WNV ecology, epidemiology, and evolution within the United States.

  1. How far does West Nile virus currently spread? What are the barriers?
  2. Are West Nile virus outbreaks caused by newly introduced viruses?
  3. Has West Nile virus adapted to regions within the United States?
  4. Do different circulating West Nile virus strains have different outbreak potential?

To answer these questions, plus many more, we need to fill in our many gaps that remain regarding West Nile virus diversity in the United States. Thus, our goal is to sequence ~4,000 West Nile virus from across the country, focusing primarily on more recently isolated viruses (2013-present).


Open data sharing and visualization

We will make our sequencing data openly available immediately after generation ( and our results can be visualized on Nextstrain (, an interactive online tool to visualize WNV spread using genomics.


We need your help

There are already dozens of collaborators joining us to better understand West Nile virus in the United States, but we need more help. Please let us know if you have a freezer full of West Nile virus samples from the last few years and/or if you plan on doing collections this year. We view this as setting up partnerships, and not as sample stealing. We will share the data as soon as it is generated so that folks can use their data however they like – as long as we can use it for our large phylogenetic study. All involved will be treated as collaborators and included as co-authors.

If you want to join our collaboration, please send us an email and provide the following information:

  • locations of sample collection (state and county)
  • years in which you have West Nile virus samples
  • the number of samples that you could provide

We’ll be happy to include you in our study and answer any questions that you may have.


Nate –
Ryan –
Kristian –