2015 provisional data for the United States • In 2015, chikungunya virus disease became a nationally notifiable condition. Cases are reported to CDC by state and local health departments using standard case definitions. • As of September 8, 2015, a total of 332 chikungunya virus disease cases have been reported to ArboNET from 37 U.S. states for 2015 (Table 1 & Map). All reported cases occurred in travelers returning from affected areas. No locally-transmitted cases have been reported from U.S. states. • A total of 112 chikungunya virus disease cases have been reported to ArboNET from U.S. territories (Table 2). All reported cases were locally-transmitted cases reported from Puerto Rico and the US Virgin Islands. • Table 1. Laboratory-confirmed chikungunya virus disease cases reported to ArboNET by state— United States, 2015 (as of September 8, 2015) • Table 2. Laboratory-confirmed chikungunya virus disease cases reported to ArboNET by territory — United States, 2015 (as of September 8, 2015)

Stephen B. Thacker CDC Library collection