Chikungunya

Chikungunya is an arthropod-borne viral disease which is transmitted by the same mosquitoes that transmit dengue, Aedes aegpyti and Aedes albopictus, and is difficult to distinguish clinically from dengue. Until recently chikungunya was limited to Africa and Asia. In the early part of the 21st Century, the disease began to occur in other regions, including major outbreaks in Reunion Island in 2005/6 and in Italy in 2007. In 2013, the disease was confirmed in the Americas for the first time, in Saint Martin in the Caribbean. As of 26 January 2015, 42 countries or territories in the Americas have been affected with over a million suspected cases.

The highest incidence was reported from Martinique, Guadeloupe, Saint Barthelemy, and Saint Martin (French part) where 18.3%, 17.5%, 17.1%, and 15.6%, respectively, of the population was affected. It is interesting to note that these countries were the first to report cases. French Guiana, the Dominican Republic, and Dominica also experienced relatively high incidence (6.5%, 5.2% and 5.2%, respectively). For reference, among American adults over 18, approximately 13% have sinusitis and 8% have hay fever.

The movie below shows the spread of the recent chikungunya epidemic in the Americas. This animation was created in ArcGIS v. 10.2.2 to show the cumulative incidence of suspected and confirmed cases of chikungunya beginning 03 January 2014 and ending 26 January 2015. The cumulative incidence is depicted using graduated symbols based on a normal quantile distribution. The Oceans layer from the ArcGIS base layer database is used as background. The data was compiled from the weekly PAHO reports and may be downloaded from this site in Excel format.