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Review
. 2021 May 6;15(5):e0009190.
doi: 10.1371/journal.pntd.0009190. eCollection 2021 May.

A 20-year historical review of West Nile virus since its initial emergence in North America: Has West Nile virus become a neglected tropical disease?

Shannon E Ronca  1   2   3 , Jeanne C Ruff  1   2 , Kristy O Murray  1   2   3
Affiliations
Review

A 20-year historical review of West Nile virus since its initial emergence in North America: Has West Nile virus become a neglected tropical disease?

Shannon E Ronca et al. PLoS Negl Trop Dis. .

Abstract

After the unexpected arrival of West Nile virus (WNV) in the United States in 1999, the mosquito-borne virus quickly spread throughout North America. Over the past 20 years, WNV has become endemic, with sporadic epizootics. Concerns about the economic impact of infection in horses lead to the licensure of an equine vaccine as early as 2005, but few advances regarding human vaccines or treatments have since been made. There is a high level of virus transmission in hot/humid, subtropical climates, and high morbidity that may disproportionately affect vulnerable populations including the homeless, elderly, and those with underlying health conditions. Although WNV continues to cause significant morbidity and mortality at great cost, funding and research have declined in recent years. These factors, combined with neglect by policy makers and amenability of control measures, indicate that WNV has become a neglected tropical disease.

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Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Epidemic curve of WNV human cases in the US and Canada, 1999–2019.
WNV, West Nile virus.
Fig 2
Fig 2. WNV strains over time.
This image was reproduced with permission from N. Grubaugh from the data available at https://nextstrain.org/WNV/NA [21,45]. WNV, West Nile virus.
Fig 3
Fig 3. Number of NIH awards granted since 2000.
NIH, National Institutes of Health.
Fig 4
Fig 4. Trend of WNV publications over time.
These reflect only those archived in PubMed. WNV, West Nile virus.
See this image and copyright information in PMC

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