Outcome of West Nile fever in older adults

OBJECTIVES: To determine the effect of clinical presentation and cognitive changes on the postdischarge outcome in older adult patients with West Nile fever (WNF). DESIGN: Retrospective, cohort analysis. SETTING: Meir Hospital located in the center of Israel in the Sharon region. PARTICIPANTS: Thirty-two patients aged 65 and older hospitalized during a WNF outbreak. MEASUREMENTS: All patients' charts were analyzed retrospectively with special emphasis on their cognitive and functional state. A follow-up examination of patients with functional decline at discharge was performed after 3 months. RESULTS: A change in consciousness, rather than in cognition, predicted the outcome. The death rate was 22% (7/32); all fatal cases were aged 78 and older. Similarly, the functional decline and residual damage appeared only in the older age group (greater than or equal to75). Eighty-eight percent of the survivors returned to their premorbid function. In contrast to other viral infections, chronic conditions in the subjects had no effect on the outcome. CONCLUSIONS: In older adults, WNF carries a high death rate, but the outcome is favorable for the survivors.