Clinical description and follow-up investigation of human West Nile virus cases.

OBJECTIVES

The objective of this study was to investigate long-term outcomes after West Nile virus infection.

METHODS

We reviewed the medical records of persons reported with West Nile virus in Tennessee in 2002 and interviewed cases 1 year after acute illness.

RESULTS

In 2002, 56 cases of West Nile virus were reported in Tennessee; 48 (84%) had meningitis or encephalitis. Of those, 9 (19%) died during acute infection and 12 (25%) died within 6 months of illness onset. Patients with West Nile virus neurologic illness spent a median of 10 days in the hospital and were unable to resume normal activities for a median of 25 days. One year later, 12 of 22 (55%) persons reported that they were not fully recovered, with symptoms including fatigue, weakness, difficulty ambulating, and memory problems.

CONCLUSIONS

West Nile virus infection leads to high rates of mortality and substantial persistent morbidity. Prevention efforts should be targeted to populations at highest risk of severe sequelae.