Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2007 Jan;135(1):57-66.
doi: 10.1017/S0950268806006662. Epub 2006 Jun 6.

Environmental and ecological determinants of West Nile virus occurrence in horses in North Dakota, 2002

M Ndiva Mongoh  1 , M L Khaitsa, N W Dyer
Affiliations

Environmental and ecological determinants of West Nile virus occurrence in horses in North Dakota, 2002

M Ndiva Mongoh et al. Epidemiol Infect. 2007 Jan.

Abstract

West Nile virus (WNV) outbreak in North Dakota in 2002 included over 569 horse cases, clustered mainly in the eastern and northeastern parts of the state. The pattern of occurrence observed suggested existence of specific environmental and ecological factors that increased the risk for infection and illness in those locations. We developed a predictive model with factors that explained the pattern of WNV occurrence observed. Results indicated that surface elevation, temperature, precipitation, reported WNV-positive birds, reported WNV-positive humans, and reported WNV-positive mosquitoes were important predictors of occurrence in horses. However, case distance from water bodies was not significant in the model. Future predictive models of WNV occurrence in horses should take into account these factors in order to improve accuracy and reliability. Research into other potential determinants such as horse management factors are required to determine more differential risk factors associated with WNV occurrence in horses.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Geographical distribution (by county) of WNV cases in horses in North Dakota, 2002.
Fig. 2
Fig. 2
Occurrence (by county) of WNV cases in horses, birds, humans and mosquitoes in North Dakota, 2002.
Fig. 3
Fig. 3
Geographical distribution (by county) of WNV cases in horses in North Dakota, 2003.
Fig. 4
Fig. 4
Predicted occurrence of WNV cases in horses in North Dakota, 2002, using the model. The equation for this model is: y=10·7+Factor 1 (4·23∗human cases) – Factor 2 (0·79∗mosquito cases) – Factor 3 (1·58∗temperature)+Factor 4 (6·11∗elevation)+Factor 5 (5·09∗precipitation) – Factor 6 (3·19∗dist waterbodies) – Factor 7 (0·57∗birds cases). Percentage of values are used to create the prediction maps to enable comparison between maps.
Fig. 5
Fig. 5
Predicted occurrence of WNV cases in horses in North Dakota, 2003, using the model. The equation for this model is: y=0·79+Factor 1 (0·52∗human cases)+Factor 2 (0·27∗temperature) – Factor 3 (0·07∗elevation)+Factor 4 (0·03∗mosquito cases)+Factor 5 (0·10∗precipitation)+Factor 6+Factor 7 (0·42∗dist waterbodies). Percentage of values are used to create the prediction maps to enable comparison between maps.
See this image and copyright information in PMC

References

    1. Rappole JH, Derrickson SR, Hubalek Z. Migratory birds and spread of West Nile Virus in the western hemisphere. Emerging Infectious Diseases. 2000;6:319–328. - PMC - PubMed
    1. Nash D et al. The outbreak of West Nile virus infection in the New York City area in 1999. New England Journal of Medicine. 2001;344:1807–1814. - PubMed
    1. Reisen Wet al. West Nile virus in California. Emerging Infectious Diseases2004101369–1378. - PMC - PubMed
    1. Marfin AA, Gubler DJ. West Nile encephalitis: an emerging disease in the United States. Clinical Infectious Diseases. 2001;33:1713–1719. - PubMed
    1. Garmendia AE, Van Kruiningen HJ, French RA. The West Nile virus: its recent emergence in North America. Microbes and Infection. 2001;3:223–229. - PubMed

Publication types

MeSH terms