Epidemiological features of West Nile Virus (WNV) disease among children (<18 years of age) reported to the Centers for Disease Control and Prevention from 1999 through 2007 were analyzed and compared with those of adult WNV neuroinvasive disease (WNND), in a study at CDC&P, Fort Collins, CO. Of 1478 pediatric WNV cases reported, 443 (30%) had WNND, 1009 (68%) were classified as WN fever, and 26 (2%) were unclassified. The majority had onset between July and September. Among all cases of WNND reported, only 4% were in children. Of the 443 cases of pediatric WNND, 208 (47%) presented as meningitis, 163 (37%) as encephalitis or meningoencephalitis, 5 (1%) as acute flaccid paralysis (AFP), and 67 (15%) as unspecified WNND. The median age of WNND cases was 12 years. Three patients died. Median annual incidence of WNND was 0.07/100,000 children, in 40 states, primarily in South Dakota, Wyoming, and New Mexico. Of a total 11,081 WNND cases in the US, 4% occurred in children. The proportion classified as WNND was 30% and the same in children (<18 yrs) as in young adults (18-49 yrs). Older adults (>50 yrs) with WNND were more often classified with encephalitis (59%) than meningitis (23%), whereas in children and young adults, meningitis was preponderant (47% and 51%, respectively). [1]

COMMENT. According to the AAP Red Book (2006), the majority of pediatric WNV infections are asymptomatic, 20% have WNF, and <1% develop neuroinvasive disease. Risk of WNND increases with age and is highest in adults >60 years. Patients with WNND present with neck stiffness and headache, typical of aseptic meningitis, mental status changes of encephalitis, movement disorders such as tremor, seizures, or acute flaccid paralysis clinically similar to poliomyelitis or Guillain-Barre syndrome.