West Nile virus disease in children, United States, 1999-2007.

BACKGROUND: Although West Nile virus (WNV) disease has occurred predominantly among adults in the United States, children are also susceptible. Epidemiological data describing WNV disease in children are limited.

METHODS: We described the epidemiological features of WNV disease among children (<18 years of age) reported to the Centers for Disease Control and Prevention from 1999 through 2007 and compared features of pediatric and adult West Nile neuroinvasive disease (WNND).

RESULTS: Of 1478 pediatric WNV cases reported from 1999 through 2007, 443 (30%) were classified as WNND, 1009 (68%) were classified as West Nile fever, and 26 (2%) were of unknown clinical presentation. Three WNND cases were fatal. The vast majority of reported case subjects (92%) had onset of illness between July and September. Children accounted for only 4% of all of the WNND case subjects reported from 1999 to 2007, with a median annual incidence of 0.07 case subjects per 100 000 children (range: 0.00-0.19 case subjects). In children and younger adults WNND most often manifested as meningitis, in contrast to the predominance of encephalitis among older adults with WNND. The geographic distribution and temporal trends were of pediatric and adult WNND.

CONCLUSIONS: The epidemiological characteristics of WNV disease in children are similar to adult case subjects; however, WNND is more likely to manifest as meningitis in children than in older adults. WNV should be considered in the differential diagnosis for pediatric patients presenting with febrile illness, meningitis, encephalitis, or acute flaccid paralysis, particularly during seasonal outbreaks in endemic areas.