Follow-up study of Greek patients with West Nile virus neuroinvasive disease.

OBJECTIVES

To investigate the extent to which Greek patients with West Nile virus neuroinvasive disease (WNND) recovered from the initial infection in 2010, when a West Nile virus (WNV) lineage 2 outbreak took place.

METHODS

Twenty-two patients with WNND were examined 16 months after the onset of symptoms. The physical and mental function of the 22 survivors was evaluated.

RESULTS

A considerable persistent morbidity and long length of time to recovery was observed. The most common symptoms were anorexia (77.3%) and muscle weakness (72.7%), followed by memory impairment (36.4%) and depression (22.7%). Older age was correlated with memory impairment, muscle weakness, and permanent damage. A complete recovery was seen in 7/22 (31.8%) patients, while three patients presented permanent damage. The critical time-point was 1 year after the onset of symptoms; at that time the patient's health status was either highly improved or had deteriorated irreversibly.

CONCLUSIONS

WNND is associated with considerable short- and long-term morbidity and mortality. Lineage 2 strains need further scientific attention. Public health measures are needed to prevent the infection, especially in the elderly with underlying diseases.