Risk Factors for West Nile Neuroinvasive Disease and Mortality in the US, 2013-2024

Area of Science:

• Epidemiology
• Infectious Diseases
• Public Health

Background:

• West Nile virus (WNV) is a significant mosquito-borne pathogen in the U.S., causing West Nile fever and potentially severe West Nile neuroinvasive disease (WNND).
• Understanding risk factors for WNND and associated mortality is crucial for effective public health interventions and resource allocation.

Purpose of the Study:

• To identify demographic and comorbidity-related risk factors associated with the development of WNND.
• To assess the impact of WNND on all-cause mortality in infected adults.
• To inform targeted prevention strategies for high-risk populations.

Main Methods:

• Retrospective cohort study utilizing deidentified electronic medical record data from the TriNetX research network (January 2013 - December 2024).
• Inclusion of patients diagnosed with WNV infection across 65 U.S. healthcare organizations.
• Analysis of demographic characteristics, comorbidities, and medication use as potential risk factors for WNND and mortality.

Main Results:

• The study analyzed 3064 patients with WNV infection, identifying 1127 cases of WNND.
• Key risk factors for WNND included older age, male sex, chronic kidney disease (CKD), cerebrovascular disease (CEVD), hematologic malignant neoplasms, immune suppressant use, hypertension, alcohol-related disorders, and multiple sclerosis.
• WNND was a significant risk factor for 30-day mortality, with increased mortality also associated with older age, CKD, and CEVD.

Conclusions:

• Multiple comorbidities are significant risk factors for developing WNND.
• Patients with WNND face a substantially increased risk of mortality.
• Targeted prevention and intervention strategies for individuals with identified risk factors are essential to mitigate WNV-related morbidity and mortality.