• Chikungunya is not a nationally notifiable disease in the United States. However, chikungunya cases can be reported to ArboNET, the national surveillance system for arthropod-borne diseases.
• From 2006‒2013, studies identified an average of 28 people per year in the United States with positive tests for recent chikungunya virus infection (Range 5‒65 per year). All were travelers visiting or returning to the United States from affected areas, mostly in Asia. Only a quarter of the cases were reported to ArboNET.
• Beginning in 2014, cases have been identified in travelers returning from the Caribbean. As of June 10, a total of 39 chikungunya cases have been reported to ArboNET from U.S. states and territories (Table). One locally transmitted case has been reported from Puerto Rico. All other cases occurred in travelers returning from affected areas in the Caribbean (N=37) or Asia (N=1). To date, no local transmission has been identified in the continental United States.
• With the recent outbreaks in the Caribbean and the Pacific, the number of chikungunya cases among travelers visiting or returning to the United States from affected areas will likely increase. These imported cases could result in local spread of the virus in the continental United States.
The page includes a table of states with a total of 38 imported chikungunya cases; the case in Minnesota, Dr. Halverson tells us, is hers.