Demographic characteristics of 981 individuals from 13 cohorts. (A) Number of individuals from each WNV group enrolled per center. (B) Number of individuals from each WNVD group enrolled per center. (C) Age distribution of the individuals enrolled, by WNV group. (D) Age distribution of the WNVD individuals, by center. (E) Sex distribution of the individuals enrolled, by WNV group. (F) Sex distribution of the individuals enrolled, by center. WNND, WNV neuroinvasive disease, a subset of WNVD; WNE, WNV encephalitis; WNM, WNV meningitis; AFP, acute flaccid paralysis; UNS, unspecified neurological syndrome (subsets of WNND group).