Risk Factors ID”d for Poor Outcomes After West Nile Virus Infection

TUESDAY, Dec. 16, 2025 (HealthDay News) — Older age, certain comorbidities, and immunosuppression increase risk for severe West Nile disease and mortality, according to a study published online Dec. 10 in JAMA Network Open.

Seth D. Judson, M.D., from University of California, Los Angeles, and David Dowdy, M.D., Ph.D., from Johns Hopkins University in Baltimore, assessed risk factors associated with West Nile neuroinvasive disease (WNND) and mortality among adults with West Nile virus (WNV) infection using deidentified electronic medical record data from the TriNetX research network (January 2013 to December 2024).

The researchers identified 3,064 patients with a diagnosis of WNV infection, including 47 percent who were consistent with WNND. Risk factors associated with WNND included age (adjusted hazard ratio [aHR], 1.10 per decade), male sex (aHR, 1.29), cerebrovascular disease (aHR, 1.22), hematologic malignant neoplasms (aHR, 1.38), immune suppressant use (aHR, 1.43), hypertension (aHR, 1.18), alcohol-related disorders (aHR, 1.54), and multiple sclerosis (aHR, 2.34). Mortality was significantly associated with WNND (aHR, 2.49 for 30-day mortality), age (aHR, 1.32 per decade), chronic kidney disease (CKD) (aHR, 2.08), and cerebrovascular disease (aHR, 2.00).

“Our findings reveal groups that could be at particularly high risk for severe West Nile disease, and these populations could benefit from targeted preventative measures and future vaccines, if they become available,” Judson said in a statement. 

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