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. 2021 Aug;21(8):620-627.
doi: 10.1089/vbz.2021.0014. Epub 2021 Jun 2.

Characterizing Areas with Increased Burden of West Nile Virus Disease in California, 2009-2018

Mary E Danforth  1 , Marc Fischer  2 , Robert E Snyder  1 , Nicole P Lindsey  2 , Stacey W Martin  2 , Vicki L Kramer  1
Affiliations

Characterizing Areas with Increased Burden of West Nile Virus Disease in California, 2009-2018

Mary E Danforth et al. Vector Borne Zoonotic Dis. 2021 Aug.

Abstract

West Nile virus (WNV) is a mosquito-borne flavivirus that can cause severe neurological disease in humans, for which there is no treatment or vaccine. From 2009 to 2018, California has reported more human disease cases than any other state in the United States. We sought to identify smaller geographic areas within the 10 California counties with the highest number of WNV cases that accounted for disproportionately large numbers of human cases from 2009 to 2018. Eleven areas, consisting of groups of high-burden ZIP codes, were identified in nine counties within southern California and California's Central Valley. Despite containing only 2% of California's area and 17% of the state's population, these high-burden ZIP codes accounted for 44% of WNV cases reported and had a mean annual incidence that was 2.4 times the annual state incidence. Focusing mosquito control and public education efforts in these areas would lower WNV disease burden.

Keywords: California; West Nile virus; arbovirus; epidemiology; public health.

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Conflict of interest statement

The authors report no real or perceived conflicts of interest.

Figures

FIG. 1.
FIG. 1.
WNV disease cases by county (A) and ZIP code (B) of residence—California, 2009–2018 (n = 4123 cases). Detailed regional maps of ZIP code-level data are shown in Fig. 2. (B) Includes 3864 (94%) cases with known ZIP code of residence. WNV, West Nile virus.
FIG. 2.
FIG. 2.
WNV disease cases by ZIP code in (A) southern California; (B) southern Central Valley; and (C) northern Central Valley—California, 2009–2018.
See this image and copyright information in PMC

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