Epidemiology and Infection



Risk factors for encephalitis and death from West Nile virus infection


K. MURRAY a1a2c1, S. BARANIUK a1, M. RESNICK a1, R. ARAFAT a3, C. KILBORN a4, K. CAIN a1, R. SHALLENBERGER a3, T. L. YORK a4, D. MARTINEZ a4, J. S. HELLUMS a1a5, D. HELLUMS a6, M. MALKOFF a5, N. ELGAWLEY a3, W. McNEELY a3, S. A. KHUWAJA a3 and R. B. TESH a2
a1 University of Texas, School of Public Health, Houston, TX, USA
a2 University of Texas Medical Branch, Galveston, TX, USA
a3 City of Houston Department of Health and Human Services, Houston, TX, USA
a4 Harris County Public Health and Environmental Services, Houston, TX, USA
a5 University of Texas, School of Medicine, Houston, TX, USA
a6 Baylor College of Medicine, Houston, TX, USA

Article author query
murray k   [PubMed][Google Scholar] 
baraniuk s   [PubMed][Google Scholar] 
resnick m   [PubMed][Google Scholar] 
arafat r   [PubMed][Google Scholar] 
kilborn c   [PubMed][Google Scholar] 
cain k   [PubMed][Google Scholar] 
shallenberger r   [PubMed][Google Scholar] 
york tl   [PubMed][Google Scholar] 
martinez d   [PubMed][Google Scholar] 
hellums js   [PubMed][Google Scholar] 
hellums d   [PubMed][Google Scholar] 
malkoff m   [PubMed][Google Scholar] 
elgawley n   [PubMed][Google Scholar] 
mcneely w   [PubMed][Google Scholar] 
khuwaja sa   [PubMed][Google Scholar] 
tesh rb   [PubMed][Google Scholar] 

Abstract

We conducted a nested case-control study to determine potential risk factors for developing encephalitis from West Nile virus (WNV) infection. Retrospective medical chart reviews were completed for 172 confirmed WNV cases hospitalized in Houston between 2002 and 2004. Of these cases, 113 had encephalitis, including 17 deaths, 47 had meningitis, and 12 were fever cases; 67% were male. Homeless patients were more likely to be hospitalized from WNV compared to the general population. A multiple logistic regression model identified age [odds ratio (OR) 1·1, P<0·001], history of hypertension, including those cases taking hypertension-inducing drugs (OR 2·9, P=0·012), and history of cardiovascular disease (OR 3·5, P=0·061) as independent risk factors for developing encephalitis from WNV infection. After adjusting for age, race/ethnicity (being black) (OR 12·0, P<0·001), chronic renal disease (OR 10·6, P<0·001), hepatitis C virus (OR 23·1, P=0·0013), and immunosuppression (OR 3·9, P=0·033) were identified as risk factors for death from WNV infection.

(Accepted March 8 2006)
(Published Online May 4 2006)


Correspondence:
c1 1200 Herman Pressler, Rm. 707, Houston, TX 77030, USA. (Email: Kristy.O.Murray@uth.tmc.edu)


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